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Start on Cloud

A unified distributed database ready for your transactional, analytical, and AI workloads.

DEPLOY YOUR WAY

OceanBase Cloud

The best way to deploy and scale OceanBase

OceanBase Enterprise

Run and manage OceanBase on your infra

TRY OPEN SOURCE

OceanBase Community Edition

The free, open-source distributed database

OceanBase seekdb

Open source AI native search database

Customer Stories

Real-world success stories from enterprises across diverse industries.

View All
BY USE CASES

Mission-Critical Transactions

Global & Multicloud Application

Elastic Scaling for Peak Traffic

Real-time Analytics

Active Geo-redundancy

Database Consolidation

Comprehensive knowledge hub for OceanBase.

Blog

Live Demos

Training & Certification

Documentation

Official technical guides, tutorials, API references, and manuals for all OceanBase products.

View All
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OceanBase Database

SQL - V4.3.5

  • Documentation updates
  • What's New
  • What is OceanBase Database
    • Overview
    • Differences between Enterprise Edition and Community Edition
    • System architecture
    • Compatibility with Oracle
      • Overview
      • SQL data types
      • Built-in functions
      • System views
    • Compatibility with MySQL
    • Limitations
  • Get Started
    • Quick start with OceanBase Database Community Edition
    • Learn OceanBase SQL
      • Before you begin
      • Basic SQL operations (MySQL mode)
      • Basic SQL operations (Oracle mode)
    • Build a sample application (MySQL mode)
      • Build a Python application
      • Build a Java application
      • Build a C application
      • Build a Go application
    • Build a sample application (Oracle mode)
      • Build a Java application
      • Build a C application
    • Try out advanced features of OceanBase Database
      • Scalable OLTP
        • Run the TPC-C benchmark in OceanBase Database
        • Try out the hot row update capability of OceanBase Database
      • Try out operational OLAP
      • Try out parallel import and data compression
      • Try out the multi-tenant feature
    • Video tutorial
  • Develop
    • Develop applications (MySQL mode)
      • Connect to OceanBase Database
        • Overview
        • Connect to an OceanBase tenant by using the mysql client
        • Connect to an OceanBase tenant by using OBClient
        • Connect to OceanBase Database by using ODC
        • Connect to OceanBase Database by using DBeaver
        • Connect to OceanBase Database by using Navicat
        • Use database connection pool
          • Database connection pool configuration
          • Tomcat
          • c3p0
          • Proxool
          • HikariCP
          • DBCP
          • Commons Pool
          • Druid
          • JDBC
      • Sample applications
        • Java
          • Spring Boot
          • Spring Batch
          • Spring JDBC
          • Spring Data JPA
          • Hibernate
          • MyBatis
          • Connector/J
          • TestContainers
        • Python
          • mysqlclient
          • PyMySQL
          • MySQL-connector-python
        • C
          • MySQL Connector/C
        • Go
          • Go-SQL-Driver/MySQL
          • GORM
        • PHP
          • EXT
          • MySQLi
          • PDO
        • Rust
          • Connect to OceanBase Database by using Rust
          • Connect to OceanBase Database by using SeaORM
      • Plan database objects
        • Create a database
        • Create a table group
        • Create a table
        • Create an index
        • Create an external table
      • Write data
        • Insert data
        • Update data
        • Delete data
        • Replace data
        • Generate test data in batches
      • Read data
        • Single-table queries
        • Join tables
          • INNER JOIN queries
          • FULL JOIN queries
          • LEFT JOIN queries
          • RIGHT JOIN queries
          • Subqueries
          • Lateral derived table
        • Use operators and functions in queries
          • Use arithmetic operators in queries
          • Use numerical functions in queries
          • Use string concatenation operators in queries
          • Use string functions in queries
          • Use datetime functions in queries
          • Use type conversion functions in queries
          • Use aggregate functions in queries
          • Use NULL-related functions in queries
          • Use the CASE conditional operator in queries
          • Lock query results with SELECT FOR UPDATE
          • Use the SELECT ... LOCK IN SHARE MODE statement to lock query results
        • Use a DBLink in queries
        • Set operations
      • Transactions
        • Overview
        • Start a transaction
        • Savepoints
          • Mark a savepoint
          • Roll back a transaction to a savepoint
          • Release a savepoint
        • Commit a transaction
        • Roll back a transaction
      • Application errors
        • Troubleshooting guidelines
          • About error codes
          • Error handling specifications for MySQL-compatible applications
        • Common errors and troubleshooting practices
          • Disconnected from the server, with ERROR 2013 reported
          • Idle transaction timed out, with ERROR 6002 reported
          • Transaction timed out, with ERROR 4012 reported
          • User locked, with ERROR 3118 reported
          • Incorrect user password, with ERROR 1045 reported
          • Table already exists, with ERROR 1050 reported
          • Table does not exist, with ERROR 1146 reported
          • Duplicate data inserted, with ERROR 1062 reported
          • ERROR 1215 reported in foreign key addition
          • Data truncated while being inserted, with ERROR 1265 reported
    • Develop applications (Oracle mode)
      • Connect to OceanBase Database
        • Overview
        • Connect to an OceanBase tenant by using OBClient
        • Connect to OceanBase Database by using ODC
        • Use database connection pool
          • Database connection pool configuration
          • Tomcat
          • c3p0
          • Proxool
          • HikariCP
          • DBCP
          • Commons Pool
          • Druid
      • Sample applications
        • Java
          • OceanBase Connector/J
          • Spring Boot
          • Spring Batch
          • Spring Data JDBC
          • Spring Data JPA
          • Hibernate
          • MyBatis
          • JFinal
        • Python
          • Python Driver Oracle Mode
        • C/C++
          • OceanBase Connector/C
          • OceanBase Connector/ODBC
          • SqlSugar
      • Plan database objects
        • Create a table group
        • Create a table
        • Create an index
        • Create an external table
      • Write data
        • Insert data
        • Update data
        • Delete data
        • Replace data
        • Generate test data in batches
      • Read data
        • Single-table queries
        • Join tables
          • INNER JOIN queries
          • FULL JOIN queries
          • LEFT JOIN queries
          • RIGHT JOIN queries
          • Subqueries
          • Lateral derived tables
        • Use operators and functions in queries
          • Use arithmetic operators in queries
          • Use numerical functions in queries
          • Use string concatenation operators in queries
          • Use string functions in queries
          • Use datetime functions in queries
          • Use type conversion functions in queries
          • Use aggregate functions in queries
          • Use NULL-related functions in queries
          • Use CASE functions in queries
          • Use the SELECT...FOR UPDATE statement to lock query results
        • Use a DBLink in queries
        • Set operations
      • Transactions
        • Overview
        • Start a transaction
        • Savepoints
          • Mark a savepoint
          • Roll back a transaction to a savepoint
        • Commit a transaction
        • Roll back a transaction
      • Application errors
        • Troubleshooting guidelines
          • About error codes
          • Error handling specifications for Oracle-compatible applications
        • Common errors and troubleshooting practices
          • Idle transaction timed out, with Error OBE-24761 reported
          • Transaction timed out, with Error OBE-00600 reported
          • User locked, with ERROR 3118 reported
          • Incorrect user password, with ERROR 1045 reported
          • Table already exists, with Error OBE-00955 reported
          • Table does not exist, with Error OBE-04043 reported
          • Duplicate data inserted, with Error OBE-00001 reported
          • Error OBE-00600 reported in foreign key addition
          • Inconsistent data types, with Error OBE-00932 reported
  • Deploy
    • Overview
    • HA deployment solutions for OceanBase clusters
    • Deploy OceanBase Database Enterprise Edition
      • Deployment process
      • Before deployment
        • Prepare servers
        • Configure servers
        • Prepare installation packages
        • Deploy OAT
      • Deploy through GUI
        • Configure deployment environment using OAT
          • Add a server
        • Deploy OCP
          • Overview
          • Upload installation packages
          • Create MetaDB
          • Deploy OCP
        • Deploy OceanBase clusters using OCP
          • Deploy a standalone OceanBase database by using OCP
          • Deploy a two-replica OceanBase cluster with the arbitration service by using OCP
          • Deploy a single-replica OceanBase cluster by using OCP
          • Deploy a three-replica OceanBase cluster by using OCP
        • (Optional) Deploy ODP
      • Deploy through CLI
        • Configure deployment environment
          • Initialize an OBServer node by using oatcli
          • (Optional) Configure the clock source
        • Deploy OceanBase clusters using CLI
          • Deploy a standalone OceanBase database by using the CLI
          • Deploy a two-replica OceanBase cluster with the arbitration service by using the CLI
          • Deploy a single-replica OceanBase cluster by using the CLI
          • Deploy a three-replica OceanBase cluster by using the CLI
        • (Optional) Deploy ODP
      • Deploy the Java SDK environment for OceanBase Database
    • Deploy OceanBase Database Community Edition
      • Overview
      • Deploy locally
        • Software and hardware requirements
        • Before deployment
          • (Optional) Check resources
          • (Optional) Set password-free SSH login
          • (Optional) Configure the clock source
          • (Optional) Perform disk planning
          • (Optional) Configure limits.conf
          • (Optional) Configure sysctl.conf
          • (Optional) Disable the firewall and SELinux
          • (Optional) Create a user
        • Deploy through GUI
          • Deploy an OceanBase cluster by using the obd GUI
          • Deploy an OceanBase cluster through the GUI of OCP
        • Deploy OceanBase Database in a production environment by using the CLI
        • Deploy OceanBase Database by using systemd
        • Deploy OceanBase Database in a container
      • Deploy an OceanBase cluster in a Kubernetes environment
      • Install OceanBase Desktop
    • Clear an OceanBase cluster
    • Recommended configurations
  • Migrate
    • Overview
    • Migrate from MySQL databases to OceanBase Database
      • Use OMS to migrate data from a MySQL database to a MySQL tenant of OceanBase Database
      • Use mydumper and myloader to migrate data from a MySQL database to OceanBase Database
      • Use DBCAT to migrate schemas from a MySQL database to OceanBase Database
      • Use DataX to migrate table data from a MySQL database to OceanBase Database
      • Use CloudCanal to migrate data from a MySQL database to OceanBase Database
      • Use Canal to synchronize data from a MySQL database to OceanBase Database
      • Use Flink CDC to synchronize data from a MySQL database to OceanBase Database
      • Use ChunJun to migrate data from a MySQL database to OceanBase Database
    • Migrate from OceanBase Database to MySQL databases
      • Use OMS to migrate data from a MySQL tenant of OceanBase Database to a MySQL database
      • Use OMS to migrate incremental data from an Oracle tenant of OceanBase Database to a MySQL database
      • Use DBCAT to migrate schemas from OceanBase Database to a MySQL database
      • Use DataX to migrate table data from OceanBase Database to a MySQL database
      • Use Canal to synchronize data from OceanBase Database to a MySQL database
      • Use CloudCanal to migrate data from OceanBase Database to a MySQL database
      • Use Flink CDC to migrate data from OceanBase Database to a MySQL database
      • Use ChunJun to migrate data from OceanBase Database to a MySQL database
    • Migrate from Oracle databases to OceanBase Database
      • Use OMS to migrate data from an Oracle database to a MySQL tenant of OceanBase Database
      • Use OMS to migrate data from an Oracle database to an Oracle tenant of OceanBase Database
      • Use DBCAT to migrate schemas from an Oracle database to OceanBase Database
      • Use DataX to migrate table data from an Oracle database to OceanBase Database
    • Migrate from OceanBase Database to Oracle databases
      • Use OMS to migrate data from an Oracle tenant of OceanBase Database to an Oracle database
      • Use DBCAT to migrate schemas from OceanBase Database to an Oracle database
      • Use DataX to migrate table data from OceanBase Database to an Oracle database
    • Migrate from DB2 databases to OceanBase Database
      • Use OMS to migrate data from a DB2 LUW database to a MySQL tenant of OceanBase Database
      • Use OMS to migrate data from a DB2 LUW database to an Oracle tenant of OceanBase Database
      • Use DBCAT to migrate table schemas from a DB2 LUW database to OceanBase Database
    • Migrate from OceanBase Database to DB2 databases
      • Use OMS to migrate data from a MySQL tenant of OceanBase Database to a DB2 LUW database
      • Use OMS to migrate data from an Oracle tenant of OceanBase Database to a DB2 LUW database
    • Migrate from TiDB databases to OceanBase Database
      • Use OMS to migrate data from a TiDB database to a MySQL tenant of OceanBase Database
    • Migrate from PostgreSQL databases to OceanBase Database
      • Use OMS to migrate data from a PostgreSQL database to a MySQL tenant of OceanBase Database
    • Migrate from CSV files to OceanBase Database
      • Use DataX to migrate CSV files to OceanBase Database
      • Import data by using the LOAD DATA statement
    • Import data from SQL files to OceanBase Database
    • Migrate data between OceanBase Database
      • Use OMS to migrate data from an OceanBase tenant to another of the same type
      • Use OMS to migrate data from an OceanBase tenant to another of the same type in active-active disaster recovery scenarios
      • Use obloader & obdumper to migrate data between MySQL tenants in OceanBase Database
      • Use obloader & obdumper to migrate data from a MySQL tenant to an Oracle tenant in OceanBase Database
      • Use obloader & obdumper to migrate data between Oracle tenants in OceanBase Database
      • Use obloader & obdumper to migrate data from an Oracle tenant to a MySQL tenant in OceanBase Database
    • Migrate data using SQL statements
      • Migrate data between tables
      • Migrate resource units
      • Export data using the OUTFILE statement
    • Overview of direct load
  • Manage
    • Log in to an OceanBase tenant
    • Manage clusters
      • Overview
      • Cluster parameters
      • Common cluster operations
        • View a zone
        • View a node
        • Restart a node
        • Add a node
        • Delete a node
        • Isolate a node
        • Replace a node
        • Start a zone
        • Add a zone
        • Delete a zone
        • Modify a zone
        • Isolate a zone
        • View cluster parameters
        • Modify cluster parameters
        • Reset cluster parameters
        • Online upgrade from standalone deployment to distributed deployment
        • Upgrade a cluster
          • OceanBase Database Enterprise Edition
            • Overview
            • Upgrade an arbitration service
            • Upgrade an OceanBase cluster
            • Check upgrade results
          • OceanBase Database Community Edition
            • Upgrade OceanBase Database by using obd
      • Troubleshoot common problems
        • Failures of a minority of nodes
        • Failures of the majority of nodes
    • Manage tenants
      • Tenant introduction
      • Tenant capacity
      • Tenant types
      • User tenant introduction
      • Tenant system variables
      • Common tenant operations
        • Create a tenant
        • Resource isolation
          • Overview
          • Manage resource isolation (Oracle mode)
            • Configure cgroups
            • Configure global CPU resource isolation for frontend and backend tasks
            • Calibrate the disk performance
            • Configure resource isolation within a tenant
            • Update a plan directive
            • Delete a plan directive
            • Delete a resource management plan
            • Delete a resource group
            • Clear cgroup configurations
          • Manage resource isolation (MySQL mode)
            • Configure cgroups
            • Configure global CPU resource isolation for foreground and background tasks
            • Calibrate the disk performance
            • Configure resource isolation within a tenant
            • Update resource management plan directive
            • Delete a plan directive
            • Delete a resource management plan
            • Delete a resource group
            • Clear cgroup configurations
        • View tenant and resource information
        • View and set the tenant allowlist
        • View system variables of a tenant
        • Modify system variables of a tenant
        • Scale in/out
          • Introduction to scaling in/out
          • Plan resources
          • Modify the unit config for a tenant
          • Modify the number of resource units for a tenant
          • Modify the number of primary zones for a tenant
        • Modify attributes of a resource pool
        • Modify attributes of a tenant
        • Lock and unlock a tenant
        • Clone a tenant
        • Cancel tenant cloning
        • Drop a tenant
        • Restore a tenant
        • Rename a tenant
        • Manage resource pools
          • View resource pool information
          • Allocate a resource pool to a tenant
          • Remove resource pools from a tenant
          • Merge and split a resource pool
          • Drop a resource pool
        • Manage unit configs
          • Query unit configs
          • Modify a unit config
          • Drop a unit config
        • Manage services
          • Create a service
          • Query the service status
          • Start a service
          • Stop a service
          • Delete a service
    • Manage replicas
      • Overview
      • Use columnstore replicas
      • Replica distribution
        • Locality
        • Common locality operations
          • View locality
          • Modify locality
          • Add replicas
          • Remove replicas
          • Convert the type of a replica
          • Adjust the distribution of replicas
          • View the locality change history
          • Migrate replicas
          • Modify the number of Paxos replicas of a log stream
          • Cancel a replica task
      • Traffic distribution
      • Data distribution
      • Data load balancing
        • Overview
        • Transfer a partition
        • Cancel a partition transfer task
        • Cancel a load balancing job
    • High availability
      • High availability overview
      • Multi-replica disaster recovery
        • Data link introduction
        • ODP high availability
        • Database-level high availability
        • Disaster recovery architecture and levels
      • Physical standby database disaster recovery
        • Overview
        • Limitations
        • Create a standby tenant
          • Preparations
          • Create an empty standby tenant
          • Create a standby tenant by using the backup and restore (with complete logs) feature
          • Create a standby tenant by using the BACKUP DATABASE PLUS ARCHIVELOG feature
        • Log transmission service
          • Overview
          • Configure log transmission service
            • Set a log restore source
            • Specify a log restore endpoint
          • View log restore source information
          • View the log synchronization progress
          • Pause or resume log synchronization
          • Optimize the log synchronization performance
          • Set the log synchronization bandwidth limit
          • Specify log compression
        • Log storage service
        • Switch roles
          • Overview of tenant roles
          • Switchover
          • Failover
        • Drop primary and standby tenants
      • Arbitration high availability
        • Arbitration service overview
        • Enable the arbitration service for a tenant
        • Disable the arbitration service for a tenant
        • Modify the log stream downgrade control time
        • Query log stream upgrade/downgrade information
        • Replace the arbitration service for a cluster
        • Remove the arbitration service for a cluster
        • Clear residual cluster information
      • Manage recycle bin
        • Overview
        • Enable or disable the recycle bin
        • View objects in the recycle bin
        • Restore objects from the recycle bin
        • Purge the recycle bin
      • Flashback queries
    • Security and permissions
      • Overview
      • Identification and authentication
        • MySQL mode
          • Identity authentication
          • Password complexity
          • Login failure processing
        • Oracle mode
          • Identity authentication
          • Password complexity
          • Login failure processing
      • Access control
        • Overview
        • Users and permissions
          • Overview
          • MySQL mode
            • Privilege types in MySQL-compatible mode
            • Create a user
            • Grant direct privileges
            • Privilege delegation
            • Role management
              • Overview
              • Create a role
              • Grant privileges to a role
              • Grant a role to a user or another role
              • Activate a role
              • View roles
              • Revoke privileges from a role
              • Revoke a role from a user or another role
              • Drop a role
            • Grant indirect privileges
            • View user privileges
            • Revoke privileges
            • Lock or unlock a user
            • Drop a user
          • Oracle mode
            • Privilege types in Oracle mode
            • Create a user
            • View the information of a user
            • Grant direct privileges
            • Privilege delegation
            • Manage roles
              • Overview
              • Create a role
              • Grant a role to another role
              • Grant a role to a user
              • Activate or deactivate roles for a user
              • View roles
              • Modify a role
              • Revoke a role
              • Drop a role
            • Grant indirect privileges
            • View user privileges
            • Revoke privileges
            • Use a proxy user
            • Lock or unlock a user
            • Drop a user
        • Network security access control
        • RPC connection authentication
        • Row-level access control
      • Data transmission encryption
        • Overview
        • OBServer transmission encryption
        • ODP transmission encryption
      • Transparent data encryption
        • Overview
        • MySQL mode
          • Enable TDE for new tables
          • Enable TDE for existing tables
          • Decrypt a table
        • Oracle mode
          • Enable TDE for new tables
          • Enable TDE for existing tables
          • Decrypt a table
      • Column encryption
        • Overview of column encryption
        • Create column encryption rules
        • Manage column encryption privileges
        • Column encryption FAQ
      • Security auditing
        • Security auditing overview
        • MySQL-compatible mode
          • Enable security auditing
          • Set an auditing rule
          • View auditing records
          • Disable security auditing
        • Oracle-compatible mode
          • Enable security auditing
          • Set and view auditing rules
          • View auditing records
          • Audit user logins
          • Audit user operations
          • Audit specified database objects
    • Backup and restore
      • Physical backup and restore
      • Experience physical backup and restore with simplified deployment
      • Deploy NFS
      • Log archive
        • Overview
        • Prepare for log archiving
        • Enable ARCHIVELOG
        • Suspend archiving
        • Disable ARCHIVELOG
        • View information about pieces
        • View the archiving progress
        • View the archiving history
        • View archiving parameter settings
        • Change the log archive destination
        • Clear the archive path setting
        • Views related to log archiving
      • Data backup
        • Prepare for backup
        • Initiate a full data backup job
        • Initiate an incremental data backup job
        • Back up parameters
        • Stop a backup job
        • View the data backup progress
        • View the data backup history
        • View parameters related to data backup
        • Change the backup destination
        • Views related to data backup
      • Update `access_id` and `access_key` information for the backup or archive path
      • Clear backup data
        • Automatic cleanup of expired backups
        • Stop backup cleanup
        • Query the backup cleanup progress
        • Query the backup cleanup history
        • Backup cleanup parameter
        • Views related to backup cleanup
      • Restore data
        • Preparations
        • Perform physical restore
        • Perform restore from the specified paths
        • Cancel physical restore
        • View the physical restore progress
        • View physical restore results
        • Replay logs to a standby tenant
        • Convert a standby tenant into primary tenant
        • Upgrade a tenant after restore
        • Parameters related to physical restore
        • Views related to physical restore
      • Restore by table
        • Overview of table-level restore
        • Preparations
        • Restore by table
        • Schema recovery during table-level recovery
        • Cancel table restore
        • View the table restore progress
        • View the table restore result
        • Parameters related to table restore
        • Views related to table restore
      • Backup and restore performance tuning
    • Monitor
      • Overview
      • Metrics
        • System monitoring
          • Overview
          • Metrics
          • Wait events
          • Latch events
        • SQL monitoring
          • Overview
          • SQL audit
          • Execution plans
      • Cases
    • Logs
      • Overview
      • Log levels
      • Log stability
      • Log control
      • Log compression and decompression
      • Log metrics
      • Alert logs
      • View logs
        • Search for the logs of a specific SQL request
        • Query the log of a previous SQL request by using the SQL Trace feature
    • Daily inspection
      • Overview
      • Check cluster parameters
      • Check the host status
      • Check tenant resource usage
      • Check cluster resource usage
      • Check the OBServer node status
      • Check the NTP offset
      • Deadlock detection
      • End-to-end tracing
        • Overview
        • Process
        • Methods
        • Show end-to-end tracing information
        • Quick start: End-to-end diagnosis with obdiag
    • Performance tuning
      • Overview
      • Identify bottlenecks on the data link
      • Identify bottlenecks within components
        • ODP performance bottlenecks
        • ODP performance analysis
        • OBServer performance bottlenecks
          • Overview
          • Non-optimal plan
            • Non-optimal plan
            • Buffer tables
            • Cardinality
          • Hard parsing
          • Capacity issues
          • Internal wait events
      • SQL tuning
        • SQL tuning system
        • Execution plan optimization
          • Statistical information and row estimation
            • Overview
            • Statistical information
              • Overview
              • Collect statistical information
                • Overview
                • Manually collect statistics
                • Automatic statistics collection
              • Query statistics
              • Manage statistical information
                • Overview
                • Delete and set statistics
                • Import and export statistics
                • Lock statistics
                • Query historical versions of statistics and roll back to a specified version
                • Configure statistics collection strategies
            • Row estimation
              • Overview
              • Row estimation based on the selectivity
              • Row estimation based on the storage layer
            • Use statistical information and row estimation
          • Plan management
            • Plan cache
            • Disadvantages of the plan cache and countermeasures
            • Views related to the plan cache
          • Index selection
            • Overview
            • Reduce row reads
            • Avoid table access by index primary key
            • Avoid sorting
          • Join
            • Joins
            • Join algorithm
              • Nested loop joins
              • Hash Join
              • Merge join
              • Common business issues
            • Join types
            • Join order
          • Order and limit optimization
            • Overview
            • SORT assignment and optimization
            • Optimization in ORDER BY + LIMIT scenarios
        • Business logic optimization
          • SQL specifications
          • Schema specifications
        • Locate and analyze slow queries I
        • Locate and analyze slow queries II
        • Typical scenarios and cases
    • Troubleshooting
      • Overview
      • Bootstrap
      • Storage
        • Minor compaction and major compaction
        • Memory-related errors
        • Migration, replication, and rebuild tasks
      • Election
        • Election
        • Leader switchover exceptions
        • Absence of the leader
      • Transaction
        • Transaction-related errors
        • Transaction rollbacks
        • Long-running transactions
        • Suspended transactions
        • Idle transactions
      • Log synchronization-related errors
      • Physical standby database
        • Log synchronization stuck for the physical standby database
        • Switchover and failover issues
        • Other issues
      • Backup and restore
        • Data backup failures
        • Physical restore failures
      • Arbitration server process startup failures
      • Troubleshoot SQL execution errors
      • Application exceptions -- error messages without OceanBase error codes
      • Application exceptions -- error messages with OceanBase error codes
      • Troubleshoot application disconnection issues
    • Emergency response
      • Emergency response overview
      • Analysis, diagnosis, and decision-making procedure
      • Common emergency problem handling
        • Hardware issues
          • Node failure
          • Network failure
          • ODP failure
          • Other hardware and network issues
        • Capacity issues
          • Exceptions of SQL queries
          • Node disk I/O high
          • Node network card overload
          • Tenant memory full
          • obproxy thread exhaustion
          • Node clog disk full
          • Node data disk full
          • Tenant request queue backlog
        • Other cluster issues
          • sys tenant or RootService exceptions
          • Insufficiency or leakage of system memory
  • OceanBase AP
    • Release note for AP core features
    • Overview of OceanBase AP
    • Core features
    • Quickly try out OceanBase AP
    • Deployment
      • Overview
      • Recommended parameter configurations in AP scenarios
    • Data table design
      • Table overview
      • Best practices for data table design
        • Unit 1: Best practices for optimizing storage structures and query performance
        • Unit 2: Best practices for creating special indexes
    • Import data
      • Overview
      • Direct load
        • Overview of direct load
        • Full direct load
        • Incremental direct load
        • Import data in direct load mode by using obloader
      • Import data to an external table
      • Strategies and best practices
    • Export data
    • Query acceleration
      • Statistics
      • Accelerate queries by using materialized views
      • Select a query parallelism level
    • OceanBase data processing
    • Data visualization
    • Performance diagnosis and tuning
      • Use the DBMS_XPLAN package for performance diagnostics
      • Use the GV$SQL_PLAN_MONITOR view for performance analysis
      • Views related to AP performance analysis
    • Performance testing
    • Ecosystem integration in AP scenarios
    • Recommended practical tutorials for analytical processing
  • Vector Search
    • Overview
      • Overview of vector search
      • Core features of vector search
      • AI application workflow with OceanBase vector search
    • Quick starts
      • Perform vector search by using SQL
      • Perform a vector search by using Python
    • Vector embedding
    • Store vector data
    • Vector index
      • Overview of vector indexes
      • Vector index memory management
      • Dense index
        • Overview of dense indexes
        • Choose an index type
        • HNSW series indexes
        • IVF series indexes
      • Maintain indexes
      • Optimize index performance
    • Use SQL functions
    • Text embedding for vector search
    • Vector similarity search
    • Migrate to OceanBase Database from a vector database
    • Tutorials
      • Overview
      • Build an image search application with OceanBase Database
      • Build an intelligent Q&A assistant with OceanBase Database
    • AI integrations
      • Overview of AI integration
    • Benchmark testing with VectorDBBench
    • References
      • Overview of vector data types
      • Compatibility
      • Supported clients and languages
        • Supported clients and languages for vector search
        • pyobvector Python SDK API reference
        • Java SDK interface
    • Vector search FAQs
  • Shared storage
    • Shared storage architecture
  • Integrations
    • Overview of the ecosystem
    • ORM frameworks
      • Java
        • Spring Boot
        • Spring Batch
        • Spring JDBC
        • Spring Data JPA
        • Hibernate
        • MyBatis
      • Python
        • SQLAlchemy
        • peewee
        • Tortoise ORM
      • Go
        • GORM
        • beego ORM
      • Rust
        • SeaORM
        • Diesel
      • Ruby
        • Active Record
        • Sequel
        • Ruby on Rails
      • Node.js
        • Sequelize
        • TypeORM
        • Prisma
        • Drizzle
      • C#
        • Dapper
        • SqlSugar
        • FreeSQL
      • PHP
        • Yii 2.0 ORM
        • Laravel Eloquent ORM
        • CakePHP
    • Database version management
      • Liquibase
      • Flyway
    • Data integration
      • Flink
        • Apache Flink
        • Flink DirectLoad
        • Flink Connector OceanBase
      • dbt
      • SeaTunnel
      • Dataphin
      • Maxwell
      • Debezium
      • Spark Catalog
      • NiFi
      • Qlik Replicate
      • RisingWave CDC
    • SQL development
      • WebLogic
      • DBeaver
      • Navicat
      • DataGrip
      • TablePlus
      • DMS
    • Orchestration and scheduling
      • Airflow
      • PowerJob
      • DolphinScheduler
      • Linkis
    • Visualization tools
      • Superset
      • Excel
      • Power BI
      • Quick BI
      • Tableau
      • GuanData
      • vividime
    • Database management
      • NineData
      • Bytebase
      • DataHub
      • Zabbix
    • AI
      • OpenAI
      • Qwen
      • LangChain
      • LlamaIndex
      • Dify
      • n8n
      • Trae
      • SpringAI
      • Cline
      • Cursor
      • Continue
      • MCP Toolbox
      • CamelAI
      • Firecrawl
      • Hugging Face
      • Ollama
      • Google Gemini
      • Cloudflare Workers AI
      • DB GPT
      • Jina AI
      • Augment Code
      • Claude Code
      • Kiro
  • Tutorials
    • Build an image search application with OceanBase Database
    • Build an intelligent Q&A chatbot with OceanBase
    • Build a cultural tourism assistant with OceanBase multi-model integration
    • Build a real-time data warehouse and visual dashboard with OceanBase
    • Analyze data in OceanBase Database using Superset
    • Build a WordPress website with OceanBase Database
    • Use direct load to accelerate massive data import
  • Reference
    • OceanBase concepts
      • OceanBase Database architecture
      • Development of OceanBase Database
      • Multi-tenant architecture
        • Overview
        • Compatibility modes
        • Tenants
        • Tenants and resource management
          • Tenant resource management
          • Multi-tenant resource isolation
          • Resource unit balancing
      • Database objects
        • Oracle mode
          • Introduction
            • Overview
            • Database object types
            • Database object storage
            • Dependencies between database objects
          • Tables
            • Overview
            • Data type
              • Overview
              • Character data types
              • Numeric data types
              • Datetime data types
              • ROWID data types
              • LOB data types
              • Format model
                • Overview
                • Number format models
                • Datetime format models
              • Multi-model data types
            • Integrity constraints
            • Table storage
            • Table compression
            • Partitioned table
            • Replicated table
            • Tables with and without a primary key
            • Temporary tables
            • Table groups
          • Indexes
            • Overview of indexes
            • Local and global indexes
            • Unique and non-unique indexes
            • Use indexes
            • Index storage
          • Partitions
            • Overview
            • Partitioning keys
            • Partitioning types
            • Partitioned indexes
            • External table partitions
          • Views
            • Views in a database
            • Standard views
              • Standard views
              • Overview
              • OceanBase-specific views
              • Oracle-compatible views
              • View operations and data access
            • Materialized views
              • Materialized views
              • Materialized view logs
              • Creation and update strategies for materialized views
          • Other objects
            • Sequences
            • Synonyms
          • System views
            • Dictionary views
            • Performance views
          • Data integrity
            • Overview
            • Integrity constraint type
              • Overview
              • NOT NULL constraints
              • UNIQUE KEY constraints
              • PRIMARY KEY constraints
              • FOREIGN KEY constraints
              • CHECK constraints
            • Use of integrity constraints
        • MySQL mode
          • Introduction
            • Overview
            • Database object types
            • Database object storage
            • Dependencies between database objects
          • Tables
            • Overview
            • Data type
              • Overview
              • Numeric data types
              • Datetime data types
              • Character data types
              • LOB data types
              • Multi-model data types
              • Spatial data types
              • JSON data types
            • Integrity constraints
            • Table storage
            • Table compression
            • Partitioned table
            • Replicated table
            • Tables with and without a primary key
            • Temporary tables
            • Table groups
          • Indexes
            • Overview of indexes
            • Local and global indexes
            • Unique and non-unique indexes
            • Spatial indexes
            • Full-text index
            • Use indexes
            • Index storage
          • Partitions
            • Overview
            • Partitioning keys
            • Partitioning types
            • Partitioned indexes
            • External table partitions
          • Views
            • Views in a database
            • Standard views
              • Overview
              • Overview
              • OceanBase-specific views
              • MySQL-compatible views
              • Oracle-compatible views in MySQL tenants
              • Oracle-compatible views in the sys tenant
              • View operations and data access
            • Materialized views
              • Materialized views
              • Materialized view logs
              • Creation and update strategies for materialized views
          • System views
            • Dictionary views
            • Performance views
          • Data integrity
            • Overview
            • Integrity constraint type
              • Overview
              • NOT NULL constraints
              • UNIQUE KEY constraints
              • PRIMARY KEY constraints
              • Foreign key constraints
            • Use of integrity constraints
      • Distributed database objects
        • Overview
        • Cluster architecture
        • Data partitions and replicas
          • Overview
          • Log streams
          • Partition replica type
            • Overview
            • Full-featured replica
            • Read-only replicas
            • Columnstore replica
          • Multi-replica consensus protocols
          • Data balancing
            • Intra-tenant balancing
            • Views and parameters related to data balancing
        • Dynamic scaling
          • Cluster scaling
          • Tenant resource scaling
            • Overview
            • Horizontal scaling of tenant resources
            • Vertical scaling of tenant resources
            • Cross-zone management of tenant resources
      • Data link
        • Overview
        • Database proxy
          • Overview
          • SQL routing
          • Connection management
          • ODP configuration management
          • Logs and monitoring
        • Database connector
          • Overview
          • OBCI
          • OceanBase Connector/J
          • OceanBase Connector/C
        • Cross-data source access through DBLink
          • DBLink in MySQL mode
          • DBLink in Oracle mode
      • User interface and query language
        • SQL
          • Introduction
            • Overview
            • SQL data access
            • SQL standards
          • SQL statements
            • Overview
            • DDL statements
            • Monitor DDL execution progress
            • DML statements
            • DCL
          • Execution process of SQL queries
          • Query SQL execution plans
          • Distributed execution plan
            • Perform distributed execution and parallel queries
            • Generate distributed execution plans
            • Run and disable a parallel query
            • Manage distributed execution plans
            • Perform parameter tuning for PX
        • PL
          • PL concepts
            • Oracle mode
              • Subprograms
              • Stored procedures
              • Functions
              • Triggers
              • Packages
            • MySQL mode
              • Subprograms
              • Stored procedures
              • Functions
              • Triggers
          • PL subprogram execution mechanism
        • Client programming languages
      • Transaction management
        • Transaction
          • Overview
          • Transaction structure
          • Statement-level atomicity
          • GTS
          • Transaction control
            • Overview
            • Active transactions
            • Savepoint
            • Transaction control statements
              • MySQL transaction control
              • Oracle transaction control
          • Redo logs
          • Local transactions
          • Distributed transaction
            • Overview
            • Two-phase commit
          • XA transactions
        • Transaction concurrency and consistency
          • Overview
          • Multi-version read consistency
          • Concurrency control
            • Overview
            • Lock mechanism
          • Transaction isolation level
            • Overview
            • Transaction isolation levels in Oracle mode
            • Transaction isolation levels in MySQL mode
          • Weak-consistency read
      • Storage architecture
        • Overview
        • Data storage
          • Data storage overview
          • MemTables
          • SSTables
          • Columnar storage
          • Compression and encoding
        • Compaction
          • Overview
          • Compaction
          • Major compaction
        • Multi-level caching in shared-nothing architecture
        • Multi-level caching in shared storage
        • Query processing
        • Data integrity
          • Detect silent data corruption
      • Data reliability and high availability
        • High availability architecture
          • Overview
          • ODP high availability
          • Leader election in distributed systems
          • Multi-replica log synchronization
          • Paxos protocol
          • Automatic handling of node failures
        • Deployment solutions for disaster recovery
        • Data protection
          • Overview
          • Flashback queries
          • Recycle bin
        • Backup and restore
          • Overview
          • Backup directory structure
          • Backup architecture
          • Restore process
        • Arbitration-based high availability solution
        • Physical Standby Database solution
      • Database security
        • Overview
        • Authentication
        • Access control
        • Data transmission encryption
        • Data storage encryption
        • Monitoring and alerting
        • Security audit
      • OBServer node architecture
        • Structure of the OBServer node installation directory
        • Configuration file
        • observer thread model
          • Threads
          • Worker threads
          • Background threads
        • Logs
        • Memory management
          • Overview
          • Memory-related parameters
          • Memory-related views
          • Memory usage logs
          • Diagnose memory errors
      • OceanBase plugin mechanism
    • System management
      • Configuration management
        • Overview
        • Set parameters
        • Set variables
      • Storage management
        • Minor compaction management
          • Overview
          • Automatically trigger a minor compaction
          • Manually initiate a minor compaction
          • View minor compaction information
          • Modify minor compaction parameters
        • Major compaction management
          • Overview
          • Automatically trigger a major compaction
          • Configure scheduled major compactions
          • Adaptive major compactions
          • Manually initiate a major compaction
          • Manually control a major compaction
          • View major compaction information
          • Modify major compaction settings
        • Data compression
          • Overview
          • Data encoding and compression
      • Memory management
        • Overview
        • Memory structure
        • Set the maximum memory for an OceanBase database
        • Manage internal system memory
        • Memory management in a tenant
        • Manage the memory of the plan cache
        • Memleak-based regular memory leak diagnostics mechanism
        • Query memory usage information
        • FAQ about memory
      • Process management
        • Overview
        • Multi-tenant threads of OceanBase Database
        • View the thread status
        • Background threads of OceanBase Database
        • FAQ about multi-tenant threads
      • Disk management
        • Configure automatic scale-out of disk space for data files
        • View the disk space used by a tenant or table
    • Database object management
      • Overview
      • MySQL mode
        • Create and manage databases
          • Create a database
          • View databases
          • Modify a database
          • Drop a database
        • Create and manage tables
          • Overview
          • Create a table
          • Column skip index attribute
          • Define an auto-increment column
          • Define column constraints
          • Query tables
          • Modify a table
          • Change the attribute of a table
          • Empty a table
          • Drop a table
          • Lock a table
          • Create and manage external tables
            • External tables
            • Create an external table
            • Add partitions for an external table
            • Manage external files
            • Data type mapping
        • Create and manage partitions
          • Overview
          • Create a partitioned table
          • Partition splitting
            • Overview
            • Manual partition splitting
            • Automatic partition splitting
          • Dynamic partitioning
            • Overview of dynamic partitioning
            • Create a dynamic partitioned table
            • Query a dynamic partitioned table
            • Modify a dynamic partitioned table
            • Dynamic partition management tasks
          • Modify partitioning rules
          • Add a partition
          • Drop a partition
          • Truncate a partition
          • Partition pruning
          • Query data in specified partitions
          • Create indexes on partitioned tables
            • Overview
            • Local indexes
            • Global indexes
          • Partition exchange
        • Create and manage table groups
          • Overview
          • Create a table group
          • Query information about a table group
          • Add tables to a table group
          • Modify the SHARDING attribute of a table group
          • Manage tables in a table group
          • Drop a table group
        • Create and manage indexes
          • Overview
          • Create an index
          • Query indexes
          • Monitor indexes
          • Drop an index
          • System functions supported for function-based indexes
          • System functions not supported for function-based indexes
        • Manage views
          • Manage standard views
          • Manage materialized views
            • Overview of materialized views
            • Materialized view log
            • Automatic management of materialized view logs
            • Create a materialized view
            • Refresh materialized views
            • Rewrite queries based on materialized views
            • Query materialized views
            • Modify the attributes of a materialized view
            • Drop a materialized view
        • Create and manage sequences
          • Create a sequence
          • Query sequences
          • Reference a sequence
          • Modify a sequence
          • Drop a sequence
        • Create and manage triggers
          • Overview
          • Create a DML trigger
          • Query trigger information
          • Drop a trigger
        • Create and manage DBLinks
          • Create a DBLink
          • Query existing DBLinks
          • Manage DBLinks
          • Use a DBLink to access data in a remote database
          • Drop a DBLink
        • Create and manage catalogs
          • Catalog overview
          • Create a catalog
          • View a catalog
          • Delete a catalog
      • Oracle mode
        • Create and manage tables
          • Overview
          • Create a table
          • Column skip index attribute
          • Define column constraints
          • Query the definition of a table
          • Modify a table
          • Change the attribute of a table
          • Empty a table
          • Drop a table
          • Lock a table
          • Create and manage external tables
            • Overview
            • Create an external table
            • Add partitions for an external table
            • Manage external files
            • Data type mapping
        • Create and manage partitions
          • Overview
          • Create a partitioned table
          • Partition splitting
            • Overview
            • Manual partition splitting
            • Automatic subpartition splitting
          • Dynamic partitioning
            • Overview of dynamic partitioning
            • Create a dynamic partitioned table
            • Query a dynamic partitioned table
            • Modify a dynamic partitioned table
            • Dynamic partition management tasks
          • Modify partitioning rules
          • Rename a partition
          • Add a partition
          • Drop a partition
          • Truncate a partition
          • Partition pruning
          • Query data in specified partitions
          • Create indexes on partitioned tables
            • Overview
            • Local indexes
            • Global indexes
          • Partition exchange
        • Create and manage table groups
          • Overview
          • Create a table group
          • Query information about a table group
          • Add tables to a table group
          • Modify the SHARDING attribute of a table group
          • Manage tables in a table group
          • Drop a table group
        • Create and manage indexes
          • Overview
          • Create an index
          • Query indexes
          • Monitor indexes
          • Drop an index
          • System functions supported for function-based indexes
          • System functions not supported for function-based indexes
        • Manage views
          • Manage standard views
          • Manage materialized views
            • Overview of materialized views
            • Materialized view logs
            • Automatic management of materialized view logs
            • Create a materialized view
            • Refresh a materialized view
            • Rewrite queries based on materialized views
            • Query materialized views
            • Modify the attributes of a materialized view
            • Drop a materialized view
        • Manage sequences
        • Manage synonyms
        • Create and manage triggers
          • Overview
          • Create a DML trigger
          • Create an INSTEAD OF trigger
          • Create a composite trigger
          • Modify and drop a trigger
          • Disable or enable a trigger
          • Query trigger information
        • Manage directory objects
        • Create and manage DBLinks
          • Create a DBLink
          • Query existing DBLinks
          • Manage DBLinks
          • Use a DBLink to access data in a remote database
          • Use a DBLink to modify the data in a remote database
          • Drop a DBLink
          • Install and configure OCI
    • Database design specifications and practices
      • Object naming conventions
        • Overview
        • Tenant naming conventions
        • User naming conventions
        • Table naming conventions
        • Field naming conventions
        • Other naming conventions
      • Object structure design specifications
        • Field design
        • Table structure design
        • Partitioned table design
        • Index design
        • Other structural designs
      • Character set specifications
      • Database connection specifications
      • Comments
      • ORM conventions
      • Exception handling
    • SQL reference
      • Introduction to SQL
      • SQL syntax
        • System tenants
          • Overview
          • ALTER SYSTEM
            • ACTIVATE STANDBY
            • ADD REPLICA
            • ADD RESTORE SOURCE
            • SET LOG_ARCHIVE_DEST
            • SET LOG_ARCHIVE_DEST_STATE
            • ARCHIVELOG
            • NOARCHIVELOG
            • ARBITRATION
            • BOOTSTRAP
            • BACKUP KEY
            • BACKUP
            • BACKUP CLUSTER PARAMETERS
            • BALANCE TASK
            • CANCEL BACKUP
            • CANCEL BALANCE JOB
            • CANCEL CLONE
            • CANCEL DELETE BACKUP
            • CANCEL MIGRATE UNIT
            • CANCEL REPLICA TASK
            • CANCEL RESTORE
            • CANCEL RECOVER TABLE
            • CANCEL TRANSFER PARTITION
            • CLEAR RESTORE SOURCE
            • MAJOR and MINOR
            • MIGRATE REPLICA
            • MIGRATE UNIT
            • MODIFY PAXOS_REPLICA_NUM
            • MODIFY REPLICA
            • MODULE DATA
            • DELETE BACKUP POLICY
            • FLUSH PLAN CACHE
            • JOB
            • SET LOG_RESTORE_SOURCE
            • PARAMETER
            • RECOVER STANDBY
            • RECOVER STANDBY CANCEL
            • REMOVE REPLICA
            • REFRESH
            • RESTORE
            • RESTORE PREVIEW
            • RECOVER TABLE
            • SET DATA_BACKUP_DEST
            • SERVER
            • SERVICE_NAME
            • SWITCHOVER
            • THROTTLE
            • TRANSFER PARTITION
            • WASH MEMORY FRAGMENTATION
            • ZONE
          • ALTER RESOURCE POOL
          • ALTER RESOURCE TENANT
          • ALTER RESOURCE UNIT
          • ALTER TENANT
          • CREATE RESOURCE POOL
          • CREATE RESOURCE UNIT
          • CREATE TENANT
          • CREATE STANDBY TENANT
          • DROP RESOURCE POOL
          • DROP RESOURCE UNIT
          • DROP TENANT
          • SET DECRYPTION
          • SET ENCRYPTION
          • SHOW RESTORE PREVIEW
        • User tenants (MySQL mode)
          • Basic elements
            • Data types
              • Overview
              • Numeric types
                • Overview
                • Integer data types
                • Fixed-point data types
                • Floating-point data types
                • Bit value data type
              • Datetime types
                • Overview
                • DATE, DATETIME, and TIMESTAMP types
                • TIME type
                • YEAR type
              • String types
                • Overview
                • CHAR and VARCHAR
                • BINARY and VARBINARY
              • Large objects and text types
                • Overview
                • BLOB types
                • TEXT types
                • STRING types
                • LOB types
              • ENUM type
              • SET type
              • JSON data types
                • Overview
                • Create a JSON value
                • Query and modify JSON values
                • Convert a JSON data type
                • Update partial JSON data
              • Spatial data types
                • Overview
                • SRS
                • Create a spatial column
                • Create a spatial index
                • Spatial data formats
              • Roaring bitmap types
                • Overview
                • Create a highly compressed bitmap column
              • Array data types
                • Overview of array element types
                • Create an array column
              • Map data types
                • Overview of the map data type
                • ## Create map columns
            • Expressions
              • Overview
              • Expression syntax
              • Data type conversion rules
            • Character set and collation
              • Overview
              • CHARACTER SET
              • Collations
              • Database-level character set and collation
              • Table-level character set and collation
              • Column-level character sets and collations
              • Character sets and collations for character expressions
              • Character sets and collations for client connection
            • Literals
              • Overview
              • Strings
              • Numbers
              • Datetime values
              • Bit values
              • Boolean values
              • NULLs
            • Schema object names
            • User-defined variables
            • Comments
          • Operators
            • Overview of operators
            • Operator precedence
            • Arithmetic operators
            • Bitwise operators
            • Comparison operators
            • Logical operators
            • Assignment operators
            • Date and time operators
            • Concatenation operators
            • BINARY operator
            • CASE conditional operator
          • Functions
            • Overview
            • Single-row functions
              • Datetime functions
                • ADDDATE
                • CONVERT_TZ
                • CURDATE
                • CURRENT_DATE
                • CURRENT_TIME
                • CURRENT_TIMESTAMP
                • CURTIME
                • DATE
                • DATE_ADD
                • DATE_FORMAT
                • DATE_SUB
                • DATEDIFF
                • DAYOFMONTH
                • DAYOFWEEK
                • DAYOFYEAR
                • EXTRACT
                • FROM_DAYS
                • FROM_UNIXTIME
                • GET_FORMAT
                • HOUR
                • LAST_DAY
                • LOCALTIME
                • LOCALTIMESTAMP
                • MAKEDATE
                • MAKETIME
                • MICROSECOND
                • MINUTE
                • MONTH
                • MONTHNAME
                • NOW
                • PERIOD_ADD
                • PERIOD_DIFF
                • QUARTER
                • SEC_TO_TIME
                • SECOND
                • STR_TO_DATE
                • SUBDATE
                • SUBTIME
                • SYSDATE
                • TIME
                • TIME_FORMAT
                • TIME_TO_SEC
                • TIME_TO_USEC
                • TIMEDIFF
                • TIMESTAMP
                • TIMESTAMPADD
                • TIMESTAMPDIFF
                • TO_DAYS
                • TO_SECONDS
                • UNIX_TIMESTAMP
                • USEC_TO_TIME
                • UTC_DATE
                • UTC_TIME
                • UTC_TIMESTAMP
                • WEEK
                • WEEKDAY
                • WEEKOFYEAR
                • YEARWEEK
                • YEAR
                • ADDTIME
                • DAYNAME
                • DAY
              • String functions
                • ASCII
                • BIN
                • BIT_LENGTH
                • CHAR
                • CHAR_LENGTH
                • CHARACTER_LENGTH
                • CONCAT
                • CONCAT_WS
                • ELT
                • EXPORT_SET
                • FIELD
                • FIND_IN_SET
                • FORMAT
                • HEX
                • INSERT
                • INSTR
                • INT2IP
                • IP2INT
                • KEYVALUE
                • LCASE
                • LEFT
                • LENGTH
                • LOCATE
                • LOWER
                • LPAD
                • LTRIM
                • MAKE_SET
                • MD5_CONCAT_WS
                • MID
                • OCT
                • OCTET_LENGTH
                • ORD
                • POSITION
                • QUOTE
                • REGEXP
                • REGEXP_INSTR
                • REGEXP_LIKE
                • REGEXP_REPLACE
                • REGEXP_SUBSTR
                • REPEAT
                • REPLACE
                • REVERSE
                • RIGHT
                • RLIKE
                • RPAD
                • RTRIM
                • SPACE
                • SPLIT_PART
                • STRCMP
                • SUBSTR
                • SUBSTRING
                • SUBSTRING_INDEX
                • TRIM
                • UCASE
                • UNHEX
                • UPPER
                • URL_DECODE
                • URL_ENCODE
                • WEIGHT_STRING
                • TO_BASE64
                • FROM_BASE64
                • SOUNDEX
              • Conversion functions
                • CAST
                • CONVERT
                • DECODE_TRACE_ID
                • SCN_TO_TIMESTAMP
                • TIMESTAMP_TO_SCN
                • TO_CHAR(character)
                • TO_CHAR(number)
                • TO_CHAR(datetime)
              • Mathematical functions
                • ABS
                • ACOS
                • ASIN
                • ATAN
                • ATAN2
                • BIT_COUNT
                • CEIL
                • CEILING
                • CONV
                • COS
                • COT
                • CRC32
                • DEGREES
                • EXP
                • FLOOR
                • GENERATOR
                • LN
                • LOG
                • LOG10
                • LOG2
                • MOD
                • NEG
                • NORMAL
                • PI
                • POW
                • POWER
                • RADIANS
                • RAND
                • RANDOM
                • RANDSTR
                • ROUND
                • SIGN
                • SIN
                • SQRT
                • TAN
                • TRUNCATE
                • UNIFORM
                • ZIPF
              • Comparison functions
                • GREATEST
                • INTERVAL
                • ISNULL
                • LEAST
              • Process control functions
                • CASE
                • IF
                • IFNULL
                • NULLIF
                • ORA_DECODE
            • Aggregate functions
              • APPROX_COUNT_DISTINCT
              • AVG
              • BIT_AND
              • BIT_OR
              • BIT_XOR
              • COUNT
              • GROUP_CONCAT
              • GROUPING
              • MAX
              • MIN
              • STD
              • STDDEV
              • STDDEV_POP
              • STDDEV_SAMP
              • SUM
              • VAR_POP
              • VAR_SAMP
              • VARIANCE
            • Analysis functions
              • APPROX_COUNT_DISTINCT
              • AVG
              • BIT_AND
              • BIT_OR
              • BIT_XOR
              • COUNT
              • CUME_DIST
              • DENSE_RANK
              • FIRST_VALUE
              • LAG
              • LAST_VALUE
              • LEAD
              • MAX
              • MIN
              • NTH_VALUE
              • NTILE
              • PERCENT_RANK
              • PERCENTILE_CONT
              • RANK
              • ROW_NUMBER
              • STD
              • STDDEV
              • STDDEV_POP
              • STDDEV_SAMP
              • SUM
              • VAR_POP
              • VAR_SAMP
              • VARIANCE
            • Encryption functions
              • AES_DECRYPT
              • AES_ENCRYPT
              • COMPRESS
              • DECODE
              • DES_DECRYPT
              • DES_ENCRYPT
              • ENCODE
              • ENCRYPT
              • ENHANCED_AES_ENCRYPT
              • ENHANCED_AES_DECRYPT
              • MD5
              • PASSWORD
              • UNCOMPRESS
              • UNCOMPRESSED_LENGTH
              • RANDOM_BYTES
              • SHA
              • SHA1
              • SHA2
              • VALIDATE_PASSWORD_STRENGTH
              • SM3
              • SM4_ENCRYPT
              • SM4_DECRYPT
            • Information functions
              • BENCHMARK
              • CHARSET
              • COERCIBILITY
              • COLLATION
              • CONNECTION_ID
              • CURRENT_ROLE
              • CURRENT_USER
              • DATABASE
              • FOUND_ROWS
              • LAST_INSERT_ID
              • LAST_INSERT_ID Behavior Description
              • ICU_VERSION
              • OB_TRANSACTION_ID
              • ROW_COUNT
              • SCHEMA
              • SESSION_USER
              • SYSTEM_USER
              • USER
              • VERSION
              • OB_VERSION
            • JSON functions
              • Overview
              • Functions for creating JSON text
                • JSON_ARRAY
                • JSON_OBJECT
                • JSON_QUOTE
              • Functions for searching JSON text
                • JSON_CONTAINS
                • JSON_CONTAINS_PATH
                • JSON_EXTRACT
                • JSON_KEYS
                • JSON_OVERLAPS
                • JSON_SEARCH
                • JSON_VALUE
                • MEMBER OF
              • Functions for modifying JSON text
                • JSON_ARRAY_APPEND
                • JSON_APPEND
                • JSON_ARRAY_INSERT
                • JSON_INSERT
                • JSON_MERGE
                • JSON_MERGE_PATCH
                • JSON_MERGE_PRESERVE
                • JSON_REMOVE
                • JSON_REPLACE
                • JSON_SET
                • JSON_UNQUOTE
              • Functions for returning JSON text properties
                • JSON_DEPTH
                • JSON_LENGTH
                • JSON_TYPE
                • JSON_VALID
              • `JSON_TABLE`
              • JSON utility functions
                • JSON_PRETTY
                • JSON_STORAGE_SIZE
              • JSON aggregate functions
                • JSON_ARRAYAGG
                • JSON_OBJECTAGG
              • JSON schema validation functions
                • JSON_SCHEMA_VALID
                • JSON_SCHEMA_VALIDATION_REPORT
            • XML functions
              • Overview
              • Functions for querying XML data
                • EXTRACTVALUE
              • Functions for modifying XML data
                • UPDATEXML
            • Spatial functions
              • Overview
              • Functions that create geometry values
              • Spatial operation functions
              • Spatial relation functions
              • Geometry property functions
              • Geometry format conversion functions
              • Spatial analysis functions
              • Spatial constructor functions
              • Spatial accessor functions
              • Spatial format conversion functions
              • Geometry processing functions
              • _ST_GeoHash
            • Performance schema functions
              • FORMAT_BYTES
              • FORMAT_PICO_TIME
            • Lock functions
              • Overview of lock functions
              • GET_LOCK
              • IS_FREE_LOCK
              • IS_USED_LOCK
              • RELEASE_ALL_LOCKS
              • RELEASE_LOCK
            • Bitmap functions
              • Overview
              • Bitmap constructors
              • Bitmap cardinality functions
              • Roaring bitmap operation functions
              • Roaring bitmap judgment functions
              • Roaring bitmap output functions
              • Roaring bitmap aggregate functions
            • Array functions
              • Overview
              • Array constructor functions
              • Array judgment functions
              • Array output functions
              • Array functions
            • Text processing functions
              • TOKENIZE
            • Audit functions
              • Overview
              • AUDIT_LOG_FILTER_REMOVE_FILTER
              • AUDIT_LOG_FILTER_REMOVE_USER
              • AUDIT_LOG_FILTER_SET_FILTER
              • AUDIT_LOG_FILTER_SET_USER
            • Map functions
              • Overview of map functions
              • Mapping constructor
              • Mapping comparison functions and operators
              • Mapping operation functions
            • Sequence functions
              • NEXTVAL(SEQ) function
              • CURRVAL(SEQ) function
            • Other functions
              • ANY_VALUE
              • BIN_TO_UUID
              • COALESCE
              • DEFAULT
              • NAME_CONST
              • INET_ATON
              • INET_NTOA
              • INET6_ATON
              • INET6_NTOA
              • IS_IPV4
              • IS_IPV4_COMPAT
              • IS_IPV6
              • IS_UUID
              • MATCH AGAINST
              • NVL
              • UUID_TO_BIN
              • SLEEP
              • UUID
              • UUID_SHORT
              • VALUES
          • Queries and subqueries
            • Overview
            • Subqueries
            • Joins
            • Full-text queries
          • SQL statements
            • General syntax
            • Common table expressions
            • ALTER COMPILE
            • ALTER DATABASE
            • ALTER MATERIALIZED VIEW
            • ALTER MATERIALIZED VIEW LOG
            • ALTER EXTERNAL TABLE
            • ALTER OUTLINE
            • ALTER SENSITIVE RULE
            • ALTER SEQUENCE
            • ALTER/CHANGE/MODIFY EXTERNAL_STORAGE_DEST
            • MAJOR and MINOR
            • ALTER TABLE
            • ALTER TABLEGROUP
            • ALTER TABLESPACE
            • ALTER USER
            • ALTER VIEW
            • ALTER INSTANCE ROTATE INNODB MASTER KEY
            • ANALYZE
            • CACHE INDEX
            • CREATE CONCURRENT_LIMITING_RULE
            • CREATE DATABASE LINK
            • CREATE DATABASE
            • CREATE EXTERNAL CATALOG
            • CREATE EXTERNAL TABLE
            • CREATE INDEX
            • CREATE MATERIALIZED VIEW
            • CREATE MATERIALIZED VIEW LOG
            • CREATE OUTLINE
            • CREATE FORMAT OUTLINE
            • CREATE RESTORE POINT
            • CREATE ROLE
            • CREATE SEQUENCE
            • CREATE SENSITIVE RULE
            • CREATE TABLE
            • CREATE TABLEGROUP
            • CREATE TABLESPACE
            • CREATE USER
            • CREATE VIEW
            • CHECKSUM TABLE
            • CREATE EVENT
            • DEALLOCATE PREPARE
            • DROP DATABASE LINK
            • DELETE
            • DESCRIBE
            • DROP CATALOG
            • DROP CONCURRENT_LIMITING_RULE
            • DROP DATABASE
            • DROP INDEX
            • DROP MATERIALIZED VIEW
            • DROP MATERIALIZED VIEW LOG
            • DROP OUTLINE
            • DROP ROLE
            • DROP SENSITIVE RULE
            • DROP TABLE
            • DROP TABLEGROUP
            • DROP TABLESPACE
            • DROP SEQUENCE
            • DROP USER
            • DROP VIEW
            • DROP RESTORE POINT
            • EXECUTE
            • EXPLAIN
            • FLASHBACK
            • FLUSH TABLE
            • GRANT
            • HELP
            • INSERT
            • KILL
            • LOAD DATA
            • LOAD INDEX INTO CACHE
            • LOCK TABLES
            • OPTIMIZE
            • PREPARE
            • PURGE
            • PURGE RECYCLEBIN
            • RENAME USER
            • RENAME TABLE
            • REPLACE
            • REPAIR TABLE
            • REVOKE
            • SAVEPOINT
            • SCHEMA
            • SELECT INTO
            • SELECT
              • SELECT
              • JOIN clause
              • WINDOW clause
              • UNION clause
            • SET DEFAULT ROLE
            • SET
            • SET CATALOG
            • SET CHARSET
            • SET NAMES
            • SET PASSWORD
            • SET ROLE
            • SET TRANSACTION
            • SHOW
            • SUBMIT JOB
            • SHOW JOB STATUS
            • CANCEL JOB
            • TRANSACTION
            • TRUNCATE TABLE
            • UNLOCK TABLES
            • UPDATE
            • USE
            • VALUES
            • XA TRANSACTION
          • DDL feature
            • Overview
            • Online and offline DDL operations
            • Index operations
            • Primary key operations
            • Column operations
            • Generated column operations
            • Foreign key operations
            • Table operations
            • Partition operations
            • Column type change rules
            • Conversion rules for numeric data types
          • Pseudocolumns
            • Overview of pseudocolumns
            • PARTITIONID pseudo column
            • Sequence pseudo columns
        • User tenants (Oracle mode)
          • Pseudocolumns
            • Overview
            • Hierarchical query pseudocolumns
            • Sequence pseudocolumns
            • ORA_ROWSCN pseudocolumn
            • ROWNUM pseudocolumn
            • ROWID pseudocolumn
            • PARTITIONID pseudocolumns
          • Basic elements
            • Built-in data types
              • Overview
              • Character data types
                • Overview
                • CHAR data type
                • NCHAR data type
                • NVARCHAR2 data type
                • VARCHAR2 data type
                • VARCHAR data type
              • Numeric data types
                • Overview
                • NUMBER data type
                • FLOAT data type
                • Floating-point numbers
                • Precedence of numeric data types
              • Datetime and interval data types
                • Overview
                • DATE data type
                • TIMESTAMP data type
                • TIMESTAMP WITH TIME ZONE data type
                • TIMESTAMP WITH LOCAL TIME ZONE data type
                • INTERVAL YEAR TO MONTH data type
                • INTERVAL DAY TO SECOND data type
                • Calculation of dates, timestamps, and intervals
              • RAW data type
              • Large object data types
                • Overview
                • BLOB data type
                • CLOB data type
                • LOB types
              • Rowid data types
              • User-defined data types
              • Any types
              • JSON data types
                • Overview
                • Create a column of the JSON data type
                • Query JSON data
                • Conversion rules for JSON data types
              • XML data types
                • Overview
                • XML data definition
                • Create a column of the XMLType data type
                • Query XMLType data
                • Conversion of XMLType data
              • Spatial data types
                • Overview
                • Create a spatial column
                • SDO_GEOMETRY attribute access
                • Create a spatial index
            • Data type comparison rules
              • Overview
              • Numeric value comparison rules
              • Date value comparison rules
              • Character value comparison rules
              • Data type precedence
              • Data type conversion rules
              • Security considerations for data conversion
            • Literals
              • Overview
              • Text literals
              • Numeric literals
              • Datetime literals
                • Date literals
                • Timestamp literals
              • Interval literals
            • Format model
              • Overview
              • Number format models
              • Datetime format models
              • RR datetime format element
              • String-to-date conversion rules
            • NULL value
              • Overview
              • NULLs in SQL functions
              • NULLs in comparison conditions
              • NULLs in conditional expressions
            • Annotations
              • Overview
              • Comments for SQL statements
              • Comments on schema and non-schema objects
              • Hints
                • Overview
                • Use query block name and QB_NAME hint to control query optimization
                • Hint list
                  • Global hints
                    • Optimizer Stats Hint
                    • Transform Hint
                    • Other hints under the GLOBAL hint
                  • Optimized hints
                    • Access path hints under the Optimized Hint type
                    • Join Order Hints in the Optimized Hint Category
                    • Join operation hints in the Optimized Hint category
                    • Subquery hints under the Optimized Hint category
                    • Group By Hint
                    • DISTINCT hint
                    • Set Hint
                    • Distributed DML hints in the Optimized Hint category
                  • Transform hints
                    • Stmt Transform Hint
                    • Cost Based Transform Hint
                    • Heuristics transform hints
                    • Other hints under the Transform Hint type
                  • Outline related hints
                  • Other hints
            • Database objects
              • Schema objects
              • Non-schema objects
            • Database naming conventions
              • Overview
              • Suggestions on schema object names
            • Database object reference methods
              • Overview
              • Reference schema objects
              • Reference objects in a remote database
                • Create a DBLink
                • Reference a DBLink
              • Refer to partitioned tables and indexes
              • Reference an attribute or method of an object type
            • Character sets and collations
          • Operators
            • Overview of operators
            • Operator precedence
            • Arithmetic operators
            • Concatenation operator
            • Hierarchical query operators
            • Set operators
            • COLLATE operator
          • Functions
            • Overview
            • Single-row functions
              • Numeric functions
                • ABS
                • ACOS
                • ASIN
                • ATAN
                • ATAN2
                • BITAND
                • CEIL
                • COS
                • COSH
                • EXP
                • FLOOR
                • GENERATOR
                • LN
                • LOG
                • MOD
                • NANVL
                • NORMAL
                • POWER
                • REMAINDER
                • ROUND
                • RANDOM
                • RANDSTR
                • SIGN
                • SIN
                • SINH
                • SQRT
                • TAN
                • TANH
                • TRUNC
                • UNIFORM
                • WIDTH_BUCKET
                • ZIPF
              • String functions that return a string
                • CHR
                • CONCAT
                • INITCAP
                • LOWER
                • LPAD
                • LTRIM
                • NLS_LOWER
                • NLSSORT
                • NLS_UPPER
                • REGEXP_REPLACE
                • REGEXP_SUBSTR
                • REPLACE
                • RPAD
                • RTRIM
                • SUBSTR
                • TRANSLATE
                • TRANSLATE ... USING
                • TRIM
                • UPPER
              • String functions that return numbers
                • ASCII
                • INSTR
                • LENGTH
                • REGEXP_COUNT
                • REGEXP_INSTR
              • Datetime functions
                • ADD_MONTHS
                • CURRENT_DATE
                • CURRENT_TIMESTAMP
                • DBTIMEZONE
                • EXTRACT(datetime)
                • FROM_TZ
                • LAST_DAY
                • LOCALTIMESTAMP
                • MONTHS_BETWEEN
                • NEXT_DAY
                • NUMTODSINTERVAL
                • NUMTOYMINTERVAL
                • ROUND (date)
                • SESSIONTIMEZONE
                • SYS_EXTRACT_UTC
                • SYSDATE
                • SYSTIMESTAMP
                • TO_CHAR(datetime)
                • TO_DSINTERVAL
                • TO_TIMESTAMP
                • TO_TIMESTAMP_TZ
                • TO_YMINTERVAL
                • TRUNC (date)
                • TZ_OFFSET
              • Generic comparison functions
                • GREATEST
                • LEAST
              • Conversion functions
                • ASCIISTR
                • CAST
                • CHARTOROWID
                • CONVERT
                • HEXTORAW
                • NUMTODSINTERVAL
                • NUMTOYMINTERVAL
                • RAWTOHEX
                • ROWIDTOCHAR
                • ROWIDTONCHAR
                • SCN_TO_TIMESTAMP
                • TIMESTAMP_TO_SCN
                • TO_BINARY_DOUBLE
                • TO_BINARY_FLOAT
                • TO_BLOB
                • TO_CHAR(character)
                • TO_CHAR(datetime)
                • TO_CHAR(number)
                • TO_CLOB
                • TO_DATE
                • TO_DSINTERVAL
                • TO_MULTI_BYTE
                • TO_NUMBER
                • TO_NCHAR(character)
                • TO_NCHAR(datetime)
                • TO_NCHAR(number)
                • TO_SINGLE_BYTE
                • TO_TIMESTAMP
                • TO_TIMESTAMP_TZ
                • TO_YMINTERVAL
                • UNISTR
              • Encoding and decoding functions
                • DECODE
                • DUMP
                • ORA_HASH
                • VSIZE
              • Null value related functions
                • COALESCE
                • LNNVL
                • NANVL
                • NULLIF
                • NVL
                • NVL2
              • Environment and identifier functions
                • SYS_CONTEXT
                • SYS_GUID
                • UID
                • USER
                • USERENV
                • OB_VERSION
              • Hierarchical functions
                • SYS_CONNECT_BY_PATH
              • JSON functions
                • Overview
                • Create JSON text functions
                  • JSON_ARRAY
                  • JSON_OBJECT
                  • JSON_ARRAYAGG
                  • JSON_OBJECTAGG
                • Query JSON text functions
                  • JSON_VALUE
                  • JSON_QUERY
                  • JSON_EXISTS
                  • JSON_TABLE
                • Validate JSON text functions
                  • JSON_EQUAL
                • Modify JSON text functions
                  • JSON_MERGEPATCH
              • XML functions
                • Overview
                • Construct XMLType data functions
                  • XMLAGG
                  • XMLATTRIBUTES
                  • XMLELEMENT
                  • XMLPARSE
                  • XMLCONCAT
                  • XMLFOREST
                • Query XMLType data functions
                  • EXTRACT
                  • EXTRACTVALUE
                  • XMLSERIALIZE
                  • XMLCAST
                  • XMLTABLE
                  • XMLSEQUENCE
                  • EXISTSNODE
                • Modify XMLType data functions
                  • UPDATEXML
                  • INSERTCHILDXML
                  • DELETEXML
              • Spatial functions
                • Overview of spatial functions
                • Constructor functions
                • Spatial query functions
                • Format conversion functions
            • Aggregate functions
              • APPROX_COUNT_DISTINCT
              • AVG
              • CORR
              • COUNT
              • COVAR_POP
              • COVAR_SAMP
              • CUME_DIST
              • DENSE_RANK
              • GROUPING
              • KEEP
              • LISTAGG
              • MAX
              • MEDIAN
              • MIN
              • PERCENT_RANK
              • PERCENTILE_CONT
              • PERCENTILE_DISC
              • RANK
              • REGR_(Linear Regression)
              • ROLLUP
              • STDDEV
              • STDDEV_POP
              • STDDEV_SAMP
              • SUM
              • VAR_POP
              • VAR_SAMP
              • VARIANCE
              • WMSYS.WM_CONCAT/WM_CONCAT
              • GROUP_ID
              • GROUPING_ID
            • Analysis functions
              • Overview
              • AVG
              • CORR
              • COUNT
              • COVAR_POP
              • COVAR_SAMP
              • CUME_DIST
              • DENSE_RANK
              • FIRST_VALUE
              • KEEP
              • LAG
              • LAST_VALUE
              • LEAD
              • LISTAGG
              • MAX
              • MEDIAN
              • MIN
              • NTILE
              • NTH_VALUE
              • PERCENT_RANK
              • PERCENTILE_CONT
              • PERCENTILE_DISC
              • RANK
              • RATIO_TO_REPORT
              • REGR_(Linear Regression)
              • ROW_NUMBER
              • STDDEV
              • STDDEV_POP
              • STDDEV_SAMP
              • SUM
              • VAR_POP
              • VAR_SAMP
              • VARIANCE
              • WMSYS.WM_CONCAT/WM_CONCAT
            • Information functions
              • OB_TRANSACTION_ID
            • Sequence functions
              • NEXTVAL(SEQ) function
              • CURRVAL(SEQ) function
          • Expressions
            • Overview
            • Simple expressions
            • Compound expressions
            • Case expressions
            • Column expressions
            • CURSOR expressions
            • Datetime expressions
            • Function expressions
            • Interval expressions
            • Scalar subquery expressions
            • Type constructor expressions
            • Expression list
          • Conditions
            • Overview
            • Condition precedence
            • Comparison conditions
            • Floating-point conditions
            • Logical conditions
            • Pattern-matching conditions
            • NULL conditions
            • Compound conditions
            • BETWEEN condition
            • EXISTS condition
            • IN condition
          • Queries and subqueries
            • Overview
            • Simple queries
            • Hierarchical queries
            • Composite queries
            • JOIN queries
            • Subqueries
            • Lateral derived tables
            • DUAL table query
          • SQL statements
            • DDL
              • ALTER EXTERNAL TABLE
              • ALTER INDEX
              • ALTER KEYSTORE
              • ALTER MATERIALIZED VIEW
              • ALTER MATERIALIZED VIEW LOG
              • ALTER OUTLINE
              • ALTER PROFILE
              • ALTER ROLE
              • ALTER SEQUENCE
              • ALTER SESSION
              • ALTER SYSTEM FLUSH CACHE
              • ALTER/CHANGE/MODIFY EXTERNAL_STORAGE_DEST
              • ALTER SYSTEM SET PARAMETER
              • ALTER TABLE
              • ALTER TABLEGROUP
              • ALTER TABLESPACE
              • ALTER USER
              • COMMENT
              • CREATE CONTEXT
              • CREATE CONCURRENT_LIMITING_RULE
              • CREATE DIRECTORY
              • CREATE DATABASE LINK
              • CREATE EXTERNAL CATALOG
              • CREATE EXTERNAL TABLE
              • CREATE INDEX
              • CREATE KEYSTORE
              • CREATE MATERIALIZED VIEW
              • CREATE MATERIALIZED VIEW LOG
              • CREATE OUTLINE
              • CREATE PROFILE
              • CREATE FORMAT OUTLINE
              • CREATE ROLE
              • CREATE SEQUENCE
              • CREATE SYNONYM
              • CREATE TABLE
              • CREATE TABLEGROUP
              • CREATE TABLESPACE
              • CREATE USER
              • CREATE VIEW
              • DROP CATALOG
              • DROP CONTEXT
              • DROP CONCURRENT_LIMITING_RULE
              • DROP DATABASE LINK
              • DROP DIRECTORY
              • DROP INDEX
              • DROP MATERIALIZED VIEW
              • DROP MATERIALIZED VIEW LOG
              • DROP OUTLINE
              • DROP PROFILE
              • DROP ROLE
              • DROP SEQUENCE
              • DROP SYNONYM
              • DROP TABLE
              • DROP TABLEGROUP
              • DROP TABLESPACE
              • DROP USER
              • DROP VIEW
              • RENAME
              • TRUNCATE TABLE
              • MAJOR and MINOR
            • DML
              • DELETE
              • INSERT
              • MERGE
              • PURGE
              • EXPLAIN
              • SELECT
                • SIMPLE SELECT
                • Set-based SELECT
                • WITH CLAUSE
                • JOIN clause
              • UPDATE
            • DCL
              • ANALYZE
              • ALTER SYSTEM KILL SESSION
              • AUDIT
              • COMMIT
              • FLASHBACK TABLE BEFORE DROP
              • GRANT
              • KILL
              • LOAD DATA
              • LOCK TABLE
              • REVOKE
              • ROLLBACK
              • SAVEPOINT
              • SELECT INTO
              • SET CATALOG
              • SET NAMES
              • SET PASSWORD
              • SET ROLE
              • SET VARIABLE
              • SHOW
              • SHRINK
              • TRANSACTION
          • DDL feature
            • Overview
            • Online and offline DDL operations
            • Index operations
            • Primary key operations
            • Column operations
            • Generated column operations
            • Foreign key operations
            • Table operations
            • Partition operations
            • Column type change rules
            • Conversion rules for numeric data types
      • SQL specifications and practices
        • Limitations on writing SQL statements
        • SQL writing specifications
          • SELECT statements
          • DML statement writing standards
          • DDL statements
          • Multi-table join statements
          • Table scan
          • Transactions
          • Cache
          • How to use hints
          • Others
        • SQL statement examples
          • Implicit data type conversion
          • Join tables
          • Weak consistency read
          • Paging
      • Reserved keywords (MySQL mode)
      • Reserved keywords (Oracle mode)
      • Data type conversion behavior in strict mode for MySQL tenants
    • PL reference
      • What is PL
        • PL overview
        • Main features of PL
        • PL architecture
      • PL reference (MySQL mode)
        • Syntax of PL stored programs
        • PL stored procedures
          • Overview
          • Variables in stored programs
          • Stored procedures
          • Stored objects and privilege management
          • Stored functions
          • Triggers
          • EVENT
          • Limitations on stored programs
        • PL cursors
          • Overview
          • Cursor execution process
          • Limitations on server cursors
        • PL conditional control statements
          • CASE
          • IF
          • ITERATE
          • LEAVE
          • LOOP
          • REPEAT
          • RETURN
          • WHILE
        • PL data manipulation statements
          • CALL
          • DO
        • PL data definition statements
          • ALTER FUNCTION
          • ALTER PROCEDURE
          • CREATE FUNCTION
          • CREATE PROCEDURE
          • CREATE TRIGGER
          • DROP FUNCTION
          • DROP PROCEDURE
          • DROP TRIGGER
        • PL database management statements
          • SHOW CREATE FUNCTION
          • SHOW CREATE PROCEDURE
          • SHOW CREATE TRIGGER
          • SHOW FUNCTION STATUS
          • SHOW PROCEDURE STATUS
          • SHOW TRIGGERS
        • PL related dictionary views
          • INFORMATION_SCHEMA PARAMETERS
          • INFORMATION_SCHEMA ROUTINES
          • INFORMATION_SCHEMA TRIGGERS
        • PL exception handling
          • Overview
          • DECLARE ... CONDITION
          • DECLARE ... HANDLER
          • GET DIAGNOSTICS
          • RESIGNAL
          • SIGNAL
          • Scope of procedures
          • Diagnostics area
          • Exception handling and OUT/INOUT parameters
          • Limitations on exception handling
        • PL system packages
          • Overview
          • DBMS_MVIEW
            • Overview
            • PURGE_LOG
            • REFRESH
          • DBMS_MVIEW_STATS
            • Overview
            • PURGE_REFRESH_STATS
            • SET_MVREF_STATS_PARAMS
            • SET_SYSTEM_DEFAULT
          • DBMS_PARTITION
            • DBMS_PARTITION overview
            • MANAGE_DYNAMIC_PARTITION
          • DBMS_RESOURCE_MANAGER
            • Overview
            • CREATE_CONSUMER_GROUP
            • CREATE_PLAN
            • CREATE_PLAN_DIRECTIVE
            • DELETE_CONSUMER_GROUP
            • DELETE_PLAN
            • DELETE_PLAN_DIRECTIVE
            • SET_CONSUMER_GROUP_MAPPING
            • UPDATE_PLAN_DIRECTIVE
          • DBMS_SPM
            • Overview
            • ACCEPT_SQL_PLAN_BASELINE
            • ALTER_SQL_PLAN_BASELINE
            • CANCEL_EVOLVE_TASK
            • CONFIGURE
            • DROP_EVOLVE_TASK
            • DROP_SQL_PLAN_BASELINE
            • LOAD_PLANS_FROM_CURSOR_CACHE
          • DBMS_STATS
            • Overview
            • ALTER_STATS_HISTORY_RETENTION
            • CREATE_STAT_TABLE
            • DELETE_COLUMN_STATS
            • DELETE_INDEX_STATS
            • DELETE_TABLE_STATS
            • DELETE_SCHEMA_STATS
            • DELETE_SCHEMA_PREFS
            • DELETE_SYSTEM_STATS
            • DELETE_TABLE_PREFS
            • DROP_STAT_TABLE
            • EXPORT_COLUMN_STATS
            • EXPORT_INDEX_STATS
            • EXPORT_TABLE_STATS
            • EXPORT_SCHEMA_STATS
            • FLUSH_DATABASE_MONITORING_INFO
            • GATHER_INDEX_STATS
            • GATHER_TABLE_STATS
            • GATHER_SCHEMA_STATS
            • GATHER_SYSTEM_STATS
            • GET_STATS_HISTORY_AVAILABILITY
            • GET_STATS_HISTORY_RETENTION
            • GET_PARAM
            • GET_PREFS
            • IMPORT_INDEX_STATS
            • IMPORT_COLUMN_STATS
            • IMPORT_TABLE_STATS
            • IMPORT_SCHEMA_STATS
            • LOCK_PARTITION_STATS
            • LOCK_SCHEMA_STATS
            • LOCK_TABLE_STATS
            • RESTORE_TABLE_STATS
            • RESTORE_SCHEMA_STATS
            • RESET_GLOBAL_PREF_DEFAULTS
            • RESET_PARAM_DEFAULTS
            • PURGE_STATS
            • SET_COLUMN_STATS
            • SET_INDEX_STATS
            • SET_TABLE_STATS
            • SET_GLOBAL_PREFS
            • SET_PARAM
            • SET_SCHEMA_PREFS
            • SET_SYSTEM_STATS
            • SET_TABLE_PREFS
            • UNLOCK_PARTITION_STATS
            • UNLOCK_SCHEMA_STATS
            • UNLOCK_TABLE_STATS
            • CANCEL_GATHER_STATS
          • DBMS_TRUSTED_CERTIFICATE_MANAGER
            • Overview
            • ADD_TRUSTED_CERTIFICATE
            • DELETE_TRUSTED_CERTIFICATE
            • UPDATE_TRUSTED_CERTIFICATE
          • DBMS_UDR
            • Overview
            • CREATE_RULE
            • DISABLE_RULE
            • ENABLE_RULE
            • REMOVE_RULE
          • DBMS_VECTOR
            • Overview of DBMS_VECTOR
            • REFRESH_INDEX
            • REBUILD_INDEX
            • INDEX_VECTOR_MEMORY_ESTIMATE
            • INDEX_VECTOR_MEMORY_ADVISOR
          • DBMS_WORKLOAD_REPOSITORY
            • Overview
            • ASH_REPORT
            • CREATE_SNAPSHOT
            • DROP_SNAPSHOT_RANGE
            • MODIFY_SNAPSHOT_SETTINGS
          • DBMS_XPLAN
            • Overview
            • DISPLAY_ACTIVE_SESSION_PLAN
            • DISPLAY_CURSOR
            • DISPLAY
            • DISABLE_OPT_TRACE
            • DISPLAY_SQL_PLAN_BASELINE
            • ENABLE_OPT_TRACE
            • SET_OPT_TRACE_PARAMETER
          • DBMS_LIMIT_CALCULATOR
            • Overview
            • CALCULATE_MIN_PHY_RES_NEEDED_BY_UNIT
            • CALCULATE_MIN_PHY_RES_NEEDED_BY_LOGIC_RES
            • CALCULATE_MIN_PHY_RES_NEEDED_BY_STANDBY_TENANT
          • DBMS_EXTERNAL_TABLE
            • Overview
            • AUTO_REFRESH_EXTERNAL_TABLE
        • Reserved and non-reserved PL keywords
      • PL reference (Oracle mode)
        • PL language basics
          • Character sets
          • Lexical elements
          • Syntax
          • Reference identifiers
          • Identifier scope and visibility
          • Assignment
          • Expressions
          • PL blocks
          • Subprograms
          • Error-reporting functions
        • PL data types
          • Overview
          • SQL data types
          • LOB data types
          • BOOLEAN type
          • User-defined subtypes
          • PLS_INTEGER and BINARY_INTEGER
          • Arrays
          • PL JSON data types
        • PL process control
          • Overview
          • Conditional control
          • Loop control
          • Sequential control
        • PL collections and records
          • Overview
          • Collections
          • Associative arrays
          • Varrays
          • Nested tables
          • Collection constructors
          • Collection methods
            • Overview
            • DELETE method
            • TRIM method
            • EXTEND method
            • EXISTS method
            • FIRST and LAST methods
            • COUNT method
            • LIMIT method
            • PRIOR and NEXT methods
          • Records
          • Insert records into a table and update a table by using records
          • Create and call a subprogram with record type parameters
        • PL static SQL
          • Overview
          • Cursors
            • Overview
            • Cursor attributes
            • Implicit cursors
            • Explicit cursors
            • Cursor variables
            • Use FOR loops to iterate over a cursor
            • Modify and drop a cursor
          • Transaction processing and control
          • Autonomous transactions
            • Overview
            • Control autonomous transactions
            • Autonomous triggers
            • Call autonomous functions from SQL statements
          • FORALL and BULK COLLECT
        • PL dynamic SQL
          • Overview
          • Execute dynamic SQL statements
          • DBMS_SQL system package
        • PL stored procedures and functions
          • Overview
          • Create a stored procedure
          • Create a function
          • Manage stored procedures and functions
          • Privilege control
          • Pipeline functions
            • Overview
            • Create a pipelined table function
            • Application
          • User-defined functions
            • Overview
            • Interface for user-defined aggregate functions
            • Create a user-defined aggregate function
            • Use user-defined aggregate functions
          • Collection of stored procedure information and its impact on parallel execution of SQL statements
          • PL Database Link
        • PL triggers
          • Overview
          • Create a DML trigger
          • Modify and drop a trigger
          • Disable or enable a trigger
          • Query trigger information
          • INSTEAD OF DML triggers
          • Composite DML triggers
          • System triggers
        • PL packages
          • Overview
          • Create a package
          • Overloaded programs in a package
          • Manage packages
          • Definition of the PL environment by the STANDARD package
        • PL exception handling
          • Overview
          • Compile-time warnings
          • Exception types
          • Exception handling processes
        • DDL operations on stored PL units
          • Overview
          • ALTER FUNCTION
          • ALTER PACKAGE
          • ALTER PROCEDURE
          • ALTER TRIGGER
          • ALTER TYPE
          • CREATE FUNCTION
          • CREATE PACKAGE
          • CREATE PACKAGE BODY
          • CREATE PROCEDURE
          • CREATE TRIGGER
          • CREATE TYPE
          • CREATE TYPE BODY
          • DROP FUNCTION
          • DROP PACKAGE
          • DROP PROCEDURE
          • DROP TRIGGER
          • DROP TYPE
          • DROP TYPE BODY
        • PL label security package
          • Overview
          • SA_SYSDBA policy management package
            • Overview
            • SA_SYSDBA.ALTER_POLICY
            • SA_SYSDBA.CREATE_POLICY
            • SA_SYSDBA.DROP_POLICY
          • SA_COMPONENTS label component package
            • Overview of the SA_COMPONENTS package
            • SA_COMPONENTS.ALTER_LEVEL
            • SA_COMPONENTS.CREATE_LEVEL
            • SA_COMPONENTS.DROP_LEVEL
          • SA_LABEL_ADMIN label management package
            • Overview
            • SA_LABEL_ADMIN.ALTER_LABEL
            • SA_LABEL_ADMIN.CREATE_LABEL
            • SA_LABEL_ADMIN.DROP_LABEL
          • SA_POLICY_ADMIN policy management package
            • Overview
            • SA_POLICY_ADMIN.APPLY_TABLE_POLICY
            • SA_POLICY_ADMIN.DISABLE_TABLE_POLICY
            • SA_POLICY_ADMIN.ENABLE_TABLE_POLICY
            • SA_POLICY_ADMIN.REMOVE_TABLE_POLICY
          • SA_USER_ADMIN user label management package
            • Overview
            • SA_USER_ADMIN.SET_LEVELS
          • SA_SESSION session management package
            • Overview
            • SA_SESSION.LABEL
            • SA_SESSION.RESTORE_DEFAULT_LABELS
            • SA_SESSION.ROW_LABEL
            • SA_SESSION.SET_LABEL
            • SA_SESSION.SET_ROW_LABEL
        • PL system package (Oracle mode)
          • Overview
          • DBMS_APPLICATION_INFO
            • Overview
            • READ_CLIENT_INFO
            • READ_MODULE
            • SET_ACTION
            • SET_CLIENT_INFO
            • SET_MODULE
          • DBMS_AUDIT_MGMT
            • Overview
            • CLEAN_AUDIT_TRAIL
            • CREATE_PURGE_JOB
            • DROP_PURGE_JOB
            • SET_LAST_ARCHIVE_TIMESTAMP
            • SET_PURGE_JOB_STATUS
          • DBMS_CRYPTO
            • Overview
            • ENCRYPT
            • DECRYPT
            • HASH
          • DBMS_DEBUG
            • Overview
            • ATTACH_SESSION
            • CONTINUE
            • DEBUG_ON
            • DEBUG_OFF
            • DETACH_SESSION
            • DELETE_BREAKPOINT
            • DISABLE_BREAKPOINT
            • ENABLE_BREAKPOINT
            • GET_VALUE
            • GET_VALUES
            • GET_RUNTIME_INFO
            • GET_TIMEOUT_BEHAVIOUR
            • INITIALIZE
            • PROBE_VERSION
            • PRINT_BACKTRACE
            • SET_TIMEOUT
            • SET_TIMEOUT_BEHAVIOUR
            • SET_BREAKPOINT
            • SHOW_BREAKPOINTS
          • DBMS_DESCRIBE
            • Overview
            • DESCRIBE_PROCEDURE
          • DBMS_JOB
            • Overview
            • BROKEN
            • CHANGE
            • ZONE
            • INTERVAL
            • NEXT_DATE
            • REMOVE
            • RUN
            • SUBMIT
            • USER_EXPORT
            • WHAT
          • DBMS_LOB
            • Overview
            • APPEND
            • CLOSE
            • COPY
            • CREATETEMPORARY
            • ERASE
            • FREETEMPORARY
            • GETLENGTH
            • ISOPEN
            • INSTR
            • ISTEMPORARY
            • OPEN
            • READ
            • SUBSTR
            • TRIM
            • WRITE
            • WRITEAPPEND
          • DBMS_LOCK
            • Overview
            • ALLOCATE_UNIQUE
            • ALLOCATE_UNIQUE_AUTONOMOUS
            • REQUEST
            • SLEEP
            • RELEASE
          • DBMS_METADATA
            • Overview
            • GET_DDL
            • GET_TABLE_INDEX_DDL
          • DBMS_MVIEW
            • Overview
            • PURGE_LOG
            • REFRESH
          • DBMS_MONITOR
            • Overview
            • OB_SESSION_TRACE_ENABLE
            • OB_SESSION_TRACE_DISABLE
            • OB_CLIENT_ID_TRACE_ENABLE
            • OB_CLIENT_ID_TRACE_DISABLE
            • OB_MOD_ACT_TRACE_ENABLE
            • OB_MOD_ACT_TRACE_DISABLE
            • OB_TENANT_TRACE_ENABLE
            • OB_TENANT_TRACE_DISABLE
          • DBMS_MVIEW_STAT
            • Overview
            • PURGE_REFRESH_STATS
            • SET_MVREF_STATS_PARAMS
            • SET_SYSTEM_DEFAULT
          • DBMS_OUTPUT
            • Overview
            • DISABLE
            • ENABLE
            • GET_LINE
            • GET_LINES
            • NEW_LINE
            • PUT
            • PUT_LINE
          • DBMS_PLAN_CACHE
            • Overview
            • PURGE
          • DBMS_PARTITION
            • Overview of DBMS_PARTITION
            • MANAGE_DYNAMIC_PARTITION
          • DBMS_RANDOM
            • Overview
            • INITIALIZE
            • NORMAL
            • RANDOM
            • SEED
            • STRING
            • TERMINATE
            • VALUE
          • DBMS_RESOURCE_MANAGER
            • Overview
            • CREATE_CONSUMER_GROUP
            • CREATE_PLAN
            • CREATE_PLAN_DIRECTIVE
            • DELETE_CONSUMER_GROUP
            • DELETE_PLAN
            • DELETE_PLAN_DIRECTIVE
            • SET_CONSUMER_GROUP_MAPPING
            • UPDATE_PLAN_DIRECTIVE
          • DBMS_SCHEDULER
            • Overview
            • CREATE_JOB
            • CREATE_JOB_CLASS
            • CREATE_PROGRAM
            • DEFINE_PROGRAM_ARGUMENT
            • DISABLE
            • DISABLE
            • DROP_JOB
            • DROP_JOB_CLASS
            • DROP_PROGRAM
            • ENABLE
            • ENABLE
            • GENERATE_JOB_NAME
            • PURGE_LOG
            • RUN_JOB
            • SET_ATTRIBUTE
            • SET_JOB_ARGUMENT_VALUE
            • STOP_JOB
          • DBMS_SESSION
            • Overview
            • CLEAR_ALL_CONTEXT
            • CLEAR_CONTEXT
            • CLEAR_IDENTIFIER
            • RESET_PACKAGE
            • SET_CONTEXT
            • SET_IDENTIFIER
          • DBMS_SPM
            • Overview
            • ACCEPT_SQL_PLAN_BASELINE
            • ALTER_SQL_PLAN_BASELINE
            • CANCEL_EVOLVE_TASK
            • CONFIGURE
            • DROP_EVOLVE_TASK
            • DROP_SQL_PLAN_BASELINE
            • LOAD_PLANS_FROM_CURSOR_CACHE
          • DBMS_SQL
            • Overview of DBMS_SQL
            • BIND_VARIABLE
            • CLOSE_CURSOR
            • COLUMN_VALUE
            • DEFINE_COLUMN
            • DEFINE_ARRAY
            • DESCRIBE_COLUMNS
            • EXECUTE
            • EXECUTE_AND_FETCH
            • FETCH_ROWS
            • IS_OPEN
            • LAST_ERROR_POSITION
            • OPEN_CURSOR
            • PARSE
            • VARIABLE_VALUE
          • DBMS_STATS
            • Overview
            • ALTER_STATS_HISTORY_RETENTION
            • CREATE_STAT_TABLE
            • DELETE_COLUMN_STATS
            • DELETE_INDEX_STATS
            • DELETE_TABLE_STATS
            • DELETE_SCHEMA_STATS
            • DELETE_SCHEMA_PREFS
            • DELETE_SYSTEM_STATS
            • DELETE_TABLE_PREFS
            • DROP_STAT_TABLE
            • EXPORT_COLUMN_STATS
            • EXPORT_INDEX_STATS
            • EXPORT_TABLE_STATS
            • EXPORT_SCHEMA_STATS
            • FLUSH_DATABASE_MONITORING_INFO
            • GATHER_INDEX_STATS
            • GATHER_TABLE_STATS
            • GATHER_SCHEMA_STATS
            • GATHER_SYSTEM_STATS
            • GET_STATS_HISTORY_AVAILABILITY
            • GET_STATS_HISTORY_RETENTION
            • GET_PARAM
            • GET_PREFS
            • IMPORT_INDEX_STATS
            • IMPORT_COLUMN_STATS
            • IMPORT_TABLE_STATS
            • IMPORT_SCHEMA_STATS
            • LOCK_PARTITION_STATS
            • LOCK_SCHEMA_STATS
            • LOCK_TABLE_STATS
            • RESTORE_TABLE_STATS
            • RESTORE_SCHEMA_STATS
            • RESET_GLOBAL_PREF_DEFAULTS
            • RESET_PARAM_DEFAULTS
            • PURGE_STATS
            • SET_COLUMN_STATS
            • SET_INDEX_STATS
            • SET_TABLE_STATS
            • SET_GLOBAL_PREFS
            • SET_PARAM
            • SET_SCHEMA_PREFS
            • SET_SYSTEM_STATS
            • SET_TABLE_PREFS
            • UNLOCK_PARTITION_STATS
            • UNLOCK_SCHEMA_STATS
            • UNLOCK_TABLE_STATS
            • COPY_TABLE_STATS
            • CANCEL_GATHER_STATS
          • DBMS_UDR
            • Overview
            • CREATE_RULE
            • DISABLE_RULE
            • ENABLE_RULE
            • REMOVE_RULE
          • DBMS_UTILITY
            • Overview of DBMS_UTILITY
            • ACTIVE_INSTANCES
            • CURRENT_INSTANCE
            • DB_VERSION
            • FORMAT_CALL_STACK
            • FORMAT_ERROR_BACKTRACE
            • FORMAT_ERROR_STACK
            • GET_ENDIANNESS
            • GET_HASH_VALUE
            • GET_PARAMETER_VALUE
            • GET_SQL_HASH
            • GET_TIME
            • IS_BIT_SET
            • IS_CLUSTER_DATABASE
            • NAME_RESOLVE
            • NAME_TOKENIZE
            • OLD_CURRENT_SCHEMA
            • OLD_CURRENT_USER
            • PORT_STRING
            • TABLE_TO_COMMA
            • COMMA_TO_TABLE
            • VALIDATE
          • DBMS_WORKLOAD_REPOSITORY
            • Overview
            • ASH_REPORT
          • DBMS_XA
            • Overview
            • DBMS_XA constants
            • DBMS_XA_XID object type
            • DIST_TXN_SYNC
            • XA_COMMIT
            • XA_END
            • XA_FORGET
            • XA_GETLASTOER
            • XA_PREPARE
            • XA_RECOVER
            • XA_ROLLBACK
            • XA_SETTIMEOUT
            • XA_START
          • DBMS_XMLGEN
            • Overview
            • CONVERT
          • DBMS_PROFILER
            • Overview of DBMS_PROFILER
            • START_PROFILER
            • STOP_PROFILER
            • PAUSE_PROFILER
            • RESUME_PROFILER
            • FLUSH_DATA
            • GET_VERSION
            • INTERNAL_VERSION_CHECK
            • ROLLUP_UNIT
            • ROLLUP_RUN
            • OB_INIT_OBJECTS
            • OB_DROP_OBJECTS
          • DBMS_XPLAN
            • Overview
            • DISPLAY_ACTIVE_SESSION_PLAN
            • DISPLAY_CURSOR
            • DISPLAY
            • DISABLE_OPT_TRACE
            • DISPLAY_SQL_PLAN_BASELINE
            • ENABLE_OPT_TRACE
            • SET_OPT_TRACE_PARAMETER
          • DBMS_EXTERNAL_TABLE
            • Overview
            • AUTO_REFRESH_EXTERNAL_TABLE
          • DBMS_DDL
            • Overview of DBMS_DDL
            • WRAP
            • CREATE_WRAPPED
          • ODCIConst
            • Overview
            • ODCIArgDesc.ArgType
            • ODCIEnv.CallProperty
            • ODCIEnv.Envflags
            • ODCIIndexAlter
            • ODCIIndexAlter parameter alter_option
            • ODCIIndexInfo.IndexInfoFlags
            • ODCIIndexInfo.IndexParaDegree
            • ODCIPredInfo.Flags
            • ODCIQueryInfo.Flags
            • ODCIStatsOptions.Flags
            • ODCIStatsOptions.Options
            • Return Status
            • ScnFlg
          • UTL_ENCODE
            • Overview
            • BASE64_DECODE
            • BASE64_ENCODE
          • UTL_FILE
            • Overview
            • FCLOSE
            • FFLUSH
            • FOPEN
            • FGETPOS
            • FREMOVE
            • FRENAME
            • FSEEK
            • NEW_LINE
            • GET_LINE
            • PUT
            • PUT_LINE
          • UTL_I18N
            • Overview
            • RAW_TO_CHAR
            • STRING_TO_RAW
          • UTL_RECOMP
            • Overview
            • RECOMP_PARALLEL
            • RECOMP_SERIAL
            • TRUNCATE_UTL_RECOMP_SKIP_LIST
            • POPULATE_UTL_RECOMP_SKIP_LIST
            • PARALLEL_SLAVE
          • UTL_RAW
            • Overview of UTL_RAW
            • BIT_AND
            • BIT_COMPLEMENT
            • BIT_OR
            • BIT_XOR
            • CAST_FROM_BINARY_DOUBLE
            • CAST_FROM_BINARY_FLOAT
            • CAST_FROM_BINARY_INTEGER
            • CAST_FROM_NUMBER
            • CAST_TO_BINARY_DOUBLE
            • CAST_TO_BINARY_FLOAT
            • CAST_TO_BINARY_INTEGER
            • CAST_TO_NUMBER
            • CAST_TO_RAW
            • CAST_TO_VARCHAR2
            • COMPARE
            • CONCAT
            • COPIES
            • LENGTH
            • REVERSE
            • SUBSTR
            • TRANSLATE
          • UTL_TCP
            • Overview of UTL_TCP
            • OPEN_CONNECTION
            • CLOSE_CONNECTION
            • CLOSE_ALL_CONNECTIONS
            • WRITE_LINE
            • WRITE_TEXT
            • WRITE_RAW
            • GET_LINE
            • GET_TEXT
          • UTL_SMTP
            • Overview of UTL_SMTP
            • OPEN_CONNECTION
            • CLOSE_CONNECTION
            • QUIT
            • AUTH
            • COMMAND
            • COMMAND_REPLIES
            • HELO
            • EHLO
            • MAIL
            • RCPT
            • OPEN_DATA
            • WRITE_DATA
            • WRITE_RAW_DATA
            • CLOSE_DATA
            • DATA
            • VRFY
            • HELP
            • NOOP
            • RSET
          • ANYDATA TYPE
            • Overview of ANYDATA type
            • BEGINCREATE static procedure
            • ENDCREATE member procedure
            • GET* member functions
            • GETTYPE member function
            • GETTYPENAME member function
            • PIECEWISE member procedure
            • SET* member procedures
          • XMLType
            • Overview of XMLType
            • CREATEXML
            • GETCLOBVAL
            • GETSTRINGVAL
            • TRANSFORM
            • XMLTYPE
            • EXISTSNODE
            • EXTRACT
        • Reserved PL keywords
    • System views
      • System views overview
      • System views overview
      • Views in OceanBase Database V3.x and V4.x
      • SYS tenant views
        • Dictionary views
          • information_schema.CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
          • information_schema.CHARACTER_SETS
          • information_schema.CHECK_CONSTRAINTS
          • information_schema.COLLATION_CHARACTER_SET_APPLICABILITY
          • information_schema.COLLATIONS
          • information_schema.COLUMN_PRIVILEGES
          • information_schema.COLUMNS
          • information_schema.ENGINES
          • information_schema.events
          • information_schema.GLOBAL_STATUS
          • information_schema.GLOBAL_VARIABLES
          • information_schema.KEY_COLUMN_USAGE
          • information_schema.PARAMETERS
          • information_schema.PARTITIONS
          • information_schema.PROCESSLIST
          • information_schema.QUERY_RESPONSE_TIME
          • information_schema.REFERENTIAL_CONSTRAINTS
          • information_schema.role_table_grants
          • information_schema.role_column_grants
          • information_schema.role_routine_grants
          • information_schema.ROUTINES
          • information_schema.SCHEMA_PRIVILEGES
          • information_schema.SCHEMATA
          • information_schema.SESSION_STATUS
          • information_schema.SESSION_VARIABLES
          • information_schema.STATISTICS
          • information_schema.TABLE_CONSTRAINTS
          • information_schema.TABLE_PRIVILEGES
          • information_schema.TABLES
          • information_schema.USER_PRIVILEGES
          • information_schema.VIEW_TABLE_USAGE
          • information_schema.VIEWS
          • mysql.columns_priv
          • mysql.db
          • mysql.default_roles
          • mysql.help_category
          • mysql.help_keyword
          • mysql.help_relation
          • mysql.help_topic
          • mysql.proc
          • mysql.procs_priv
          • mysql.role_edges
          • mysql.time_zone
          • mysql.time_zone_name
          • mysql.time_zone_transition
          • mysql.time_zone_transition_type
          • mysql.user
          • oceanbase.ALL_OB_EXTERNAL_TABLE_FILES
          • oceanbase.CDB_CKPT_HISTORY
          • oceanbase.CDB_OB_DATABASE_PRIVILEGE
          • oceanbase.CDB_IND_COLUMNS
          • oceanbase.CDB_IND_PARTITIONS
          • oceanbase.CDB_IND_SUBPARTITIONS
          • CDB_INDEX_USAGE
          • oceanbase.CDB_INDEXES
          • CDB_MVIEW_LOGS
          • oceanbase.CDB_MVIEW_RUNNING_JOBS
          • CDB_MVIEWS
          • CDB_MVREF_CHANGE_STATS
          • CDB_MVREF_RUN_STATS
          • CDB_MVREF_STATS
          • CDB_MVREF_STATS_PARAMS
          • CDB_MVREF_STATS_SYS_DEFAULTS
          • CDB_MVREF_STMT_STATS
          • oceanbase.CDB_OB_ACCESS_POINT
          • oceanbase.CDB_OB_LS_ARB_REPLICA_TASKS
          • oceanbase.CDB_OB_ARCHIVE_DEST
          • oceanbase.CDB_OB_ARCHIVELOG
          • oceanbase.CDB_OB_ARCHIVELOG_PIECE_FILES
          • oceanbase.CDB_OB_ARCHIVELOG_SUMMARY
          • oceanbase.CDB_OB_AUTO_INCREMENT
          • CDB_OB_AUX_STATISTICS
          • oceanbase.CDB_OB_BACKUP_DELETE_JOB_HISTORY
          • oceanbase.CDB_OB_BACKUP_DELETE_JOBS
          • oceanbase.CDB_OB_BACKUP_DELETE_POLICY
          • oceanbase.CDB_OB_BACKUP_DELETE_TASK_HISTORY
          • oceanbase.CDB_OB_BACKUP_DELETE_TASKS
          • oceanbase.CDB_OB_BACKUP_JOB_HISTORY
          • oceanbase.CDB_OB_BACKUP_JOBS
          • oceanbase.CDB_OB_BACKUP_PARAMETER
          • oceanbase.CDB_OB_BACKUP_SET_FILES
          • oceanbase.CDB_OB_BACKUP_STORAGE_INFO
          • oceanbase.CDB_OB_BACKUP_STORAGE_INFO_HISTORY
          • oceanbase.CDB_OB_BACKUP_TASK_HISTORY
          • oceanbase.CDB_OB_BACKUP_TASKS
          • oceanbase.CDB_OB_BALANCE_JOB_HISTORY
          • oceanbase.CDB_OB_BALANCE_JOBS
          • oceanbase.CDB_OB_BALANCE_TASK_HISTORY
          • oceanbase.CDB_OB_BALANCE_TASKS
          • oceanbase.CDB_OB_COLUMN_CHECKSUM_ERROR_INFO
          • oceanbase.CDB_OB_CCL_RULES
          • oceanbase.CDB_OB_CS_REPLICA_STATS
          • oceanbase.CDB_OB_DATA_DICTIONARY_IN_LOG
          • oceanbase.CDB_OB_DATABASES
          • oceanbase.CDB_OB_DEADLOCK_EVENT_HISTORY
          • oceanbase.CDB_OB_DYNAMIC_PARTITION_TABLES
          • oceanbase.CDB_OB_EXTERNAL_TABLE_FILES
          • oceanbase.CDB_OB_FREEZE_INFO
          • oceanbase.CDB_OB_IMPORT_TABLE_JOB_HISTORY
          • oceanbase.CDB_OB_IMPORT_TABLE_JOBS
          • oceanbase.CDB_OB_IMPORT_TABLE_TASK_HISTORY
          • oceanbase.CDB_OB_IMPORT_TABLE_TASKS
          • oceanbase.CDB_OB_KV_REDIS_TABLE
          • oceanbase.CDB_OB_KV_TTL_TASK_HISTORY
          • oceanbase.CDB_OB_KV_TTL_TASKS
          • oceanbase.CDB_OB_LOG_RESTORE_SOURCE
          • oceanbase.CDB_OB_LS
          • oceanbase.CDB_OB_LS_ARB_REPLICA_TASK_HISTORY
          • oceanbase.CDB_OB_LS_HISTORY
          • oceanbase.CDB_OB_LS_LOCATIONS
          • oceanbase.CDB_OB_LS_LOG_ARCHIVE_PROGRESS
          • oceanbase.CDB_OB_LS_REPLICA_TASKS
          • oceanbase.CDB_OB_LS_REPLICA_TASK_HISTORY
          • oceanbase.CDB_OB_MAJOR_COMPACTION
          • oceanbase.CDB_OB_RECOVER_TABLE_JOB_HISTORY
          • oceanbase.CDB_OB_RECOVER_TABLE_JOBS
          • oceanbase.CDB_OB_SERVICES
          • oceanbase.CDB_OB_RESTORE_HISTORY
          • oceanbase.CDB_OB_RESTORE_PROGRESS
          • oceanbase.CDB_OB_RSRC_DIRECTIVES
          • oceanbase.CDB_OB_SENSITIVE_COLUMNS
          • oceanbase.CDB_OB_SENSITIVE_RULE_PLAINACCESS_USERS
          • oceanbase.CDB_OB_SENSITIVE_RULES
          • oceanbase.CDB_OB_SERVER_SPACE_USAGE
          • oceanbase.CDB_OB_SPACE_USAGE
          • oceanbase.CDB_OB_SYS_VARIABLES
          • oceanbase.CDB_OB_STORAGE_IO_USAGE
          • oceanbase.CDB_OB_TABLE_LOCATIONS
          • oceanbase.CDB_OB_TABLEGROUP_PARTITIONS
          • oceanbase.CDB_OB_TABLEGROUP_SUBPARTITIONS
          • oceanbase.CDB_OB_TABLEGROUP_TABLES
          • oceanbase.CDB_OB_TABLEGROUPS
          • oceanbase.CDB_OB_TABLET_CHECKSUM_ERROR_INFO
          • oceanbase.CDB_OB_TABLET_REPLICAS
          • oceanbase.CDB_OB_TABLET_TO_LS
          • oceanbase.CDB_OB_TABLE_SPACE_USAGE
          • oceanbase.CDB_OB_TEMP_FILES
          • oceanbase.CDB_OB_TENANT_EVENT_HISTORY
          • oceanbase.CDB_OB_TRANSFER_PARTITION_TASKS
          • oceanbase.CDB_OB_TRANSFER_PARTITION_TASK_HISTORY
          • oceanbase.CDB_OB_TRANSFER_TASK_HISTORY
          • oceanbase.CDB_OB_TRANSFER_TASKS
          • oceanbase.CDB_OB_USERS
          • oceanbase.CDB_OB_VECTOR_INDEX_TASKS
          • oceanbase.CDB_OB_VECTOR_INDEX_TASK_HISTORY
          • oceanbase.CDB_OB_ZONE_MAJOR_COMPACTION
          • oceanbase.CDB_OBJECTS
          • oceanbase.CDB_PART_INDEXES
          • oceanbase.CDB_PART_KEY_COLUMNS
          • oceanbase.CDB_PART_TABLES
          • oceanbase.CDB_SCHEDULER_JOB_RUN_DETAILS
          • oceanbase.CDB_SUBPART_KEY_COLUMNS
          • oceanbase.CDB_SUBPARTITION_TEMPLATES
          • oceanbase.CDB_TAB_COL_STATISTICS
          • oceanbase.CDB_TAB_COLS
          • oceanbase.CDB_TAB_COLS_V$
          • oceanbase.CDB_TAB_PARTITIONS
          • oceanbase.CDB_TAB_SUBPARTITIONS
          • oceanbase.CDB_TABLES
          • oceanbase.CDB_WR_ACTIVE_SESSION_HISTORY
          • oceanbase.CDB_WR_CONTROL
          • oceanbase.CDB_WR_EVENT_NAME
          • oceanbase.CDB_WR_SNAPSHOT
          • oceanbase.CDB_WR_SQLSTAT
          • oceanbase.CDB_WR_SQLTEXT
          • oceanbase.CDB_WR_STATNAME
          • oceanbase.CDB_WR_SYS_TIME_MODEL
          • oceanbase.CDB_WR_SYSSTAT
          • oceanbase.CDB_WR_SYSTEM_EVENT
          • oceanbase.DBA_DB_LINKS
          • oceanbase.DBA_IND_PARTITIONS
          • oceanbase.DBA_IND_STATISTICS
          • oceanbase.DBA_IND_SUBPARTITIONS
          • oceanbase.DBA_INDEX_USAGE
          • oceanbase.DBA_MVIEW_DEPS
          • oceanbase.DBA_MVIEW_LOGS
          • oceanbase.DBA_MVIEW_RUNNING_JOBS
          • oceanbase.DBA_MVIEWS
          • DBA_MVREF_CHANGE_STATS
          • oceanbase.DBA_MVREF_RUN_STATS
          • oceanbase.DBA_MVREF_STATS
          • oceanbase.DBA_MVREF_STATS_PARAMS
          • oceanbase.DBA_MVREF_STATS_SYS_DEFAULTS
          • oceanbase.DBA_MVREF_STMT_STATS
          • oceanbase.DBA_OB_ACCESS_POINT
          • oceanbase.DBA_OB_ARBITRATION_SERVICE
          • oceanbase.DBA_OB_ARCHIVE_DEST
          • oceanbase.DBA_OB_ARCHIVELOG
          • oceanbase.DBA_OB_ARCHIVELOG_PIECE_FILES
          • oceanbase.DBA_OB_ARCHIVELOG_SUMMARY
          • oceanbase.DBA_OB_AUTO_INCREMENT
          • DBA_OB_AUX_STATISTICS
          • oceanbase.DBA_OB_BACKUP_DELETE_JOB_HISTORY
          • oceanbase.DBA_OB_BACKUP_DELETE_JOBS
          • oceanbase.DBA_OB_BACKUP_DELETE_POLICY
          • oceanbase.DBA_OB_BACKUP_DELETE_TASK_HISTORY
          • oceanbase.DBA_OB_BACKUP_DELETE_TASKS
          • oceanbase.DBA_OB_BACKUP_JOB_HISTORY
          • oceanbase.DBA_OB_BACKUP_JOBS
          • oceanbase.DBA_OB_BACKUP_PARAMETER
          • oceanbase.DBA_OB_BACKUP_SET_FILES
          • oceanbase.DBA_OB_BACKUP_STORAGE_INFO
          • oceanbase.DBA_OB_BACKUP_STORAGE_INFO_HISTORY
          • oceanbase.DBA_OB_BACKUP_TASK_HISTORY
          • oceanbase.DBA_OB_BACKUP_TASKS
          • oceanbase.DBA_OB_BALANCE_JOB_HISTORY
          • oceanbase.DBA_OB_BALANCE_JOBS
          • oceanbase.DBA_OB_BALANCE_TASK_HISTORY
          • oceanbase.DBA_OB_BALANCE_TASKS
          • oceanbase.DBA_OB_CLONE_HISTORY
          • oceanbase.DBA_OB_CLONE_PROGRESS
          • oceanbase.DBA_OB_CLUSTER_EVENT_HISTORY
          • oceanbase.DBA_OB_CONCURRENT_LIMIT_SQL
          • oceanbase.DBA_OB_CCL_RULES
          • oceanbase.DBA_OB_CS_REPLICA_STATS
          • oceanbase.DBA_OB_DATA_DICTIONARY_IN_LOG
          • oceanbase.DBA_OB_DATABASE_PRIVILEGE
          • oceanbase.DBA_OB_DATABASES
          • oceanbase.DBA_OB_DEADLOCK_EVENT_HISTORY
          • oceanbase.DBA_OB_DYNAMIC_PARTITION_TABLES
          • oceanbase.DBA_OB_EXTERNAL_TABLE_FILES
          • DBA_OB_FORMAT_OUTLINES
          • oceanbase.DBA_OB_FREEZE_INFO
          • oceanbase.DBA_OB_IMPORT_TABLE_JOB_HISTORY
          • oceanbase.DBA_OB_IMPORT_TABLE_JOBS
          • oceanbase.DBA_OB_IMPORT_TABLE_TASK_HISTORY
          • oceanbase.DBA_OB_IMPORT_TABLE_TASKS
          • oceanbase.DBA_OB_KV_TTL_TASK_HISTORY
          • oceanbase.DBA_OB_KV_TTL_TASKS
          • oceanbase.DBA_OB_LOG_RESTORE_SOURCE
          • oceanbase.DBA_OB_LS
          • oceanbase.DBA_OB_LS_ARB_REPLICA_TASKS
          • oceanbase.DBA_OB_LS_ARB_REPLICA_TASK_HISTORY
          • oceanbase.DBA_OB_LS_HISTORY
          • oceanbase.DBA_OB_LS_LOCATIONS
          • oceanbase.DBA_OB_LS_LOG_ARCHIVE_PROGRESS
          • oceanbase.DBA_OB_LS_REPLICA_TASKS
          • oceanbase.DBA_OB_LS_REPLICA_TASK_HISTORY
          • oceanbase.DBA_OB_MAJOR_COMPACTION
          • oceanbase.DBA_OB_OUTLINE_CONCURRENT_HISTORY
          • oceanbase.DBA_OB_OUTLINES
          • oceanbase.DBA_OB_RECOVER_TABLE_JOB_HISTORY
          • oceanbase.DBA_OB_SERVICES
          • oceanbase.DBA_OB_RECOVER_TABLE_JOBS
          • oceanbase.DBA_OB_RESOURCE_POOLS
          • oceanbase.DBA_OB_RESTORE_HISTORY
          • oceanbase.DBA_OB_RESTORE_PROGRESS
          • oceanbase.DBA_OB_ROOTSERVICE_EVENT_HISTORY
          • oceanbase.DBA_OB_RSRC_IO_DIRECTIVES
          • oceanbase.DBA_OB_RSRC_DIRECTIVES
          • oceanbase.DBA_OB_SEQUENCE_OBJECTS
          • oceanbase.DBA_OB_SERVER_EVENT_HISTORY
          • oceanbase.DBA_OB_SERVER_JOBS
          • oceanbase.DBA_OB_SERVERS
          • oceanbase.DBA_OB_STORAGE_IO_USAGE
          • oceanbase.DBA_OB_SYS_VARIABLES
          • oceanbase.DBA_OB_TABLE_LOCATIONS
          • oceanbase.DBA_OB_TABLE_OPT_STAT_GATHER_HISTORY
          • oceanbase.DBA_OB_TABLE_STAT_STALE_INFO
          • oceanbase.DBA_OB_TABLEGROUP_PARTITIONS
          • oceanbase.DBA_OB_TABLEGROUP_SUBPARTITIONS
          • oceanbase.DBA_OB_TABLEGROUP_TABLES
          • oceanbase.DBA_OB_TABLEGROUPS
          • oceanbase.DBA_OB_TABLET_REPLICAS
          • oceanbase.DBA_OB_TABLET_TO_LS
          • oceanbase.DBA_OB_TASK_OPT_STAT_GATHER_HISTORY
          • oceanbase.DBA_OB_TEMP_FILES
          • oceanbase.DBA_OB_TENANT_EVENT_HISTORY
          • oceanbase.DBA_OB_TENANT_JOBS
          • oceanbase.DBA_OB_TENANTS
          • oceanbase.DBA_OB_TRANSFER_PARTITION_TASKS
          • oceanbase.DBA_OB_TRANSFER_PARTITION_TASK_HISTORY
          • oceanbase.DBA_OB_TRANSFER_TASK_HISTORY
          • oceanbase.DBA_OB_TRANSFER_TASKS
          • DBA_OB_TRUSTED_ROOT_CERTIFICATE
          • oceanbase.DBA_OB_UNIT_CONFIGS
          • oceanbase.DBA_OB_UNIT_JOBS
          • oceanbase.DBA_OB_UNITS
          • oceanbase.DBA_OB_USER_DEFINED_RULES
          • oceanbase.DBA_OB_USERS
          • oceanbase.DBA_OB_VECTOR_INDEX_TASKS
          • oceanbase.DBA_OB_VECTOR_INDEX_TASK_HISTORY
          • oceanbase.DBA_OB_ZONE_MAJOR_COMPACTION
          • oceanbase.DBA_OB_ZONES
          • oceanbase.DBA_OB_ZONE_STORAGE
          • oceanbase.DBA_OBJECTS
          • oceanbase.DBA_PART_COL_STATISTICS
          • oceanbase.DBA_PART_HISTOGRAMS
          • oceanbase.DBA_PART_INDEXES
          • oceanbase.DBA_PART_KEY_COLUMNS
          • oceanbase.DBA_PART_TABLES
          • oceanbase.DBA_RECYCLEBIN
          • oceanbase.DBA_RSRC_CONSUMER_GROUPS
          • oceanbase.DBA_RSRC_GROUP_MAPPINGS
          • oceanbase.DBA_RSRC_PLAN_DIRECTIVES
          • oceanbase.DBA_RSRC_PLANS
          • oceanbase.DBA_SCHEDULER_JOBS
          • oceanbase.DBA_SCHEDULER_JOB_RUN_DETAILS
          • oceanbase.DBA_SCHEDULER_WINDOWS
          • oceanbase.DBA_SEQUENCES
          • oceanbase.DBA_SQL_MANAGEMENT_CONFIG
          • oceanbase.DBA_SQL_PLAN_BASELINES
          • oceanbase.DBA_SUBPART_COL_STATISTICS
          • oceanbase.DBA_SUBPART_HISTOGRAMS
          • oceanbase.DBA_SUBPART_KEY_COLUMNS
          • oceanbase.DBA_SUBPARTITION_TEMPLATES
          • oceanbase.DBA_TAB_COL_STATISTICS
          • oceanbase.DBA_TAB_HISTOGRAMS
          • oceanbase.DBA_TAB_MODIFICATIONS
          • oceanbase.DBA_TAB_PARTITIONS
          • oceanbase.DBA_TAB_STATISTICS
          • oceanbase.DBA_TAB_STATS_HISTORY
          • oceanbase.DBA_TAB_SUBPARTITIONS
          • oceanbase.DBA_WR_ACTIVE_SESSION_HISTORY
          • oceanbase.DBA_WR_CONTROL
          • oceanbase.DBA_WR_EVENT_NAME
          • oceanbase.DBA_WR_SNAPSHOT
          • oceanbase.DBA_WR_SQLSTAT
          • oceanbase.DBA_WR_SQLTEXT
          • oceanbase.DBA_WR_STATNAME
          • oceanbase.DBA_WR_SYS_TIME_MODEL
          • oceanbase.DBA_WR_SYSSTAT
          • oceanbase.DBA_WR_SYSTEM_EVENT
          • oceanbase.DBA_OB_LICENSE
        • Performance views
          • GV$ACTIVE_SESSION_HISTORY
          • GV$DML_STATS
          • GV$LATCH
          • GV$OB_ACTIVE_SESSION_HISTORY
          • GV$OB_COMPACTION_DIAGNOSE_INFO
          • GV$OB_COMPACTION_PROGRESS
          • GV$OB_COMPACTION_SUGGESTIONS
          • GV$OB_CGROUP_CONFIG
          • GV$OB_DTL_INTERM_RESULT_MONITOR
          • GV$OB_FLT_TRACE_CONFIG
          • GV$OB_FUNCTION_IO_STAT
          • GV$OB_GROUP_IO_STAT
          • GV$OB_IO_BENCHMARK
          • GV$OB_IO_CALIBRATION_STATUS
          • GV$OB_KVCACHE
          • GV$OB_KV_GROUP_COMMIT_STATUS
          • GV$OB_LOG_STAT
          • GV$OB_LOG_TRANSPORT_DEST_STAT
          • GV$OB_LS_SNAPSHOTS
          • GV$OB_MEMORY
          • GV$OB_MEMSTORE
          • GV$OB_MEMSTORE_INFO
          • GV$OB_MERGE_INFO
          • GV$OB_NIC_INFO
          • GV$OB_RPC_INCOMING
          • GV$OB_RPC_OUTGOING
          • GV$OB_PARAMETERS
          • GV$OB_PLAN_CACHE_PLAN_EXPLAIN
          • GV$OB_PLAN_CACHE_PLAN_STAT
          • GV$OB_PLAN_CACHE_STAT
          • GV$OB_PROCESSLIST
          • GV$OB_PS_ITEM_INFO
          • GV$OB_PS_STAT
          • GV$OB_PX_P2P_DATAHUB
          • GV$OB_PX_TARGET_MONITOR
          • GV$OB_PX_WORKER_STAT
          • GV$OB_QUERY_RESPONSE_TIME_HISTOGRAM
          • GV$OB_RES_MGR_SYSSTAT
          • GV$OB_SERVER_SCHEMA_INFO
          • GV$OB_SERVERS
          • GV$OB_SERVER_STORAGE
          • GV$OB_SESS_TIME_MODEL
          • GV$OB_SESSION
          • GV$OB_SHARED_STORAGE_QUOTA
          • GV$OB_SQL_AUDIT
          • GV$OB_SQL_CCL_STATUS
          • GV$SQL_JOIN_FILTER
          • GV$OB_SQL_PLAN
          • GV$SQL_PLAN_MONITOR
          • GV$OB_SQL_WORKAREA_MEMORY_INFO
          • GV$OB_SQLSTAT
          • GV$OB_SSTABLES
          • GV$OB_SS_LOCAL_CACHE
          • GV$OB_STORAGE_CACHE_TASKS
          • GV$OB_SYS_TIME_MODEL
          • GV$OB_TABLET_COMPACTION_HISTORY
          • GV$OB_TABLET_COMPACTION_PROGRESS
          • GV$OB_TABLET_LOCAL_CACHE
          • GV$OB_TENANT_MEMORY
          • GV$OB_TENANT_RESOURCE_LIMIT
          • GV$OB_TENANT_RESOURCE_LIMIT_DETAIL
          • GV$OB_TENANT_RUNTIME_INFO
          • GV$OB_TRANSACTION_PARTICIPANTS
          • GV$OB_TRANSACTION_SCHEDULERS
          • GV$OB_UNITS
          • GV$OB_VECTOR_MEMORY
          • GV$SESSION_EVENT
          • GV$SESSION_LONGOPS
          • GV$SESSION_WAIT
          • GV$SESSION_WAIT_HISTORY
          • GV$SESSTAT
          • GV$SQL_WORKAREA
          • GV$SQL_WORKAREA_ACTIVE
          • GV$SQL_WORKAREA_HISTOGRAM
          • GV$SYSSTAT
          • GV$SYSTEM_EVENT
          • gv$tenant
          • gv$tenant_memstore_allocator_info
          • GV$OB_ARBITRATION_MEMBER_INFO
          • GV$OB_ARBITRATION_SERVICE_STATUS
          • GV$OB_KV_CLIENT_INFO
          • GV$OB_LOCKS
          • GV$OB_OPT_STAT_GATHER_MONITOR
          • GV$OB_THREAD
          • GV$OB_PL_CACHE_OBJECT
          • GV$UNIT
          • GV$VECTOR_MEMORY
          • V$OB_PL_CACHE_OBJECT
          • V$ACTIVE_SESSION_HISTORY
          • V$DML_STATS
          • V$ENCRYPTED_TABLESPACES
          • V$EVENT_NAME
          • V$LATCH
          • V$OB_ACTIVE_SESSION_HISTORY
          • V$OB_ARCHIVE_DEST_STATUS
          • V$OB_COMPACTION_DIAGNOSE_INFO
          • V$OB_COMPACTION_PROGRESS
          • V$OB_COMPACTION_SUGGESTIONS
          • V$OB_COMPATIBILITY_CONTROL
          • V$OB_CGROUP_CONFIG
          • V$OB_DTL_INTERM_RESULT_MONITOR
          • V$OB_DYNAMIC_PARTITION_TABLES
          • V$OB_ENCRYPTED_TABLES
          • V$OB_FUNCTION_IO_STAT
          • V$OB_GROUP_IO_STAT
          • V$OB_IO_BENCHMARK
          • V$OB_IO_CALIBRATION_STATUS
          • V$OB_KVCACHE
          • V$OB_KV_CLIENT_INFO
          • V$OB_KV_GROUP_COMMIT_STATUS
          • V$OB_LOG_STAT
          • V$OB_LOG_TRANSPORT_DEST_STAT
          • V$OB_LS_LOG_RESTORE_STATUS
          • V$OB_LS_REPLICA_TASK_PLAN
          • V$OB_LS_SNAPSHOTS
          • V$OB_MEMORY
          • V$OB_MEMSTORE
          • V$OB_MEMSTORE_INFO
          • V$OB_MERGE_INFO
          • V$OB_NIC_INFO
          • V$OB_RPC_INCOMING
          • V$OB_RPC_OUTGOING
          • V$OB_PARAMETERS
          • V$OB_PLAN_CACHE_PLAN_EXPLAIN
          • V$OB_PLAN_CACHE_PLAN_STAT
          • V$OB_PLAN_CACHE_STAT
          • V$OB_PROCESSLIST
          • V$OB_PS_ITEM_INFO
          • V$OB_PS_STAT
          • V$OB_PX_P2P_DATAHUB
          • V$OB_PX_TARGET_MONITOR
          • V$OB_PX_WORKER_STAT
          • V$OB_QUERY_RESPONSE_TIME_HISTOGRAM
          • V$OB_RES_MGR_SYSSTAT
          • V$OB_SERVER_SCHEMA_INFO
          • V$OB_SERVERS
          • V$OB_SERVER_STORAGE
          • V$OB_SESS_TIME_MODEL
          • V$OB_SESSION
          • V$SESSION_EVENT
          • V$OB_SHARED_STORAGE_QUOTA
          • V$OB_SQL_AUDIT
          • V$OB_SQL_CCL_STATUS
          • V$SQL_JOIN_FILTER
          • V$OB_SQL_PLAN
          • V$OB_SQL_WORKAREA_MEMORY_INFO
          • V$OB_SQLSTAT
          • V$OB_SSTABLES
          • V$OB_SS_LOCAL_CACHE
          • V$OB_STORAGE_CACHE_TASKS
          • V$OB_SYS_TIME_MODEL
          • V$OB_TABLET_COMPACTION_HISTORY
          • V$OB_TABLET_COMPACTION_PROGRESS
          • V$OB_TABLET_LOCAL_CACHE
          • V$OB_TENANT_MEMORY
          • V$OB_TENANT_RESOURCE_LIMIT
          • V$OB_TENANT_RESOURCE_LIMIT_DETAIL
          • V$OB_TENANT_RUNTIME_INFO
          • V$OB_TIMESTAMP_SERVICE
          • V$OB_TRANSACTION_PARTICIPANTS
          • V$OB_TRANSACTION_SCHEDULERS
          • V$OB_UNITS
          • V$RESTORE_POINT
          • V$RSRC_PLAN
          • V$SESSION_LONGOPS
          • V$SESSION_WAIT
          • V$SESSION_WAIT_HISTORY
          • V$SESSTAT
          • V$SQL_MONITOR_STATNAME
          • V$SQL_PLAN_MONITOR
          • V$SQL_WORKAREA
          • V$SQL_WORKAREA_ACTIVE
          • V$SQL_WORKAREA_HISTOGRAM
          • V$STATNAME
          • V$SYSSTAT
          • V$SYSTEM_EVENT
          • V$OB_ARBITRATION_MEMBER_INFO
          • V$OB_ARBITRATION_SERVICE_STATUS
          • V$OB_LOCKS
          • V$OB_OPT_STAT_GATHER_MONITOR
          • V$OB_THREAD
          • V$OB_VECTOR_MEMORY
          • v$tenant_memstore_allocator_info
          • V$UNIT
          • V$VECTOR_MEMORY
      • MySQL tenant views
        • Dictionary views
          • information_schema.CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
          • information_schema.CHARACTER_SETS
          • information_schema.CHECK_CONSTRAINTS
          • information_schema.COLLATION_CHARACTER_SET_APPLICABILITY
          • information_schema.COLLATIONS
          • information_schema.COLUMN_PRIVILEGES
          • information_schema.COLUMNS
          • information_schema.ENGINES
          • information_schema.events
          • information_schema.GLOBAL_STATUS
          • information_schema.GLOBAL_VARIABLES
          • information_schema.KEY_COLUMN_USAGE
          • information_schema.PARAMETERS
          • information_schema.PARTITIONS
          • information_schema.PROCESSLIST
          • information_schema.QUERY_RESPONSE_TIME
          • information_schema.REFERENTIAL_CONSTRAINTS
          • information_schema.role_table_grants
          • information_schema.role_column_grants
          • information_schema.role_routine_grants
          • information_schema.ROUTINES
          • information_schema.SCHEMA_PRIVILEGES
          • information_schema.SCHEMATA
          • information_schema.SESSION_STATUS
          • information_schema.SESSION_VARIABLES
          • information_schema.ST_GEOMETRY_COLUMNS
          • information_schema.ST_SPATIAL_REFERENCE_SYSTEMS
          • information_schema.STATISTICS
          • information_schema.TABLE_CONSTRAINTS
          • information_schema.TABLE_PRIVILEGES
          • information_schema.TABLES
          • information_schema.USER_PRIVILEGES
          • information_schema.VIEW_TABLE_USAGE
          • information_schema.VIEWS
          • mysql.audit_log_filter
          • mysql.audit_log_user
          • mysql.columns_priv
          • mysql.db
          • mysql.default_roles
          • mysql.help_category
          • mysql.help_keyword
          • mysql.help_relation
          • mysql.help_topic
          • mysql.proc
          • mysql.procs_priv
          • mysql.role_edges
          • mysql.time_zone
          • mysql.time_zone_name
          • mysql.time_zone_transition
          • mysql.time_zone_transition_type
          • mysql.user
          • oceanbase.ALL_OB_EXTERNAL_TABLE_FILES
          • oceanbase.DBA_DB_LINKS
          • oceanbase.DBA_IND_PARTITIONS
          • oceanbase.DBA_IND_STATISTICS
          • oceanbase.DBA_IND_SUBPARTITIONS
          • oceanbase.DBA_INDEX_USAGE
          • oceanbase.DBA_MVIEW_DEPS
          • oceanbase.DBA_MVIEW_LOGS
          • oceanbase.DBA_MVIEW_RUNNING_JOBS
          • oceanbase.DBA_MVIEWS
          • DBA_MVREF_CHANGE_STATS
          • oceanbase.DBA_MVREF_RUN_STATS
          • oceanbase.DBA_MVREF_STATS
          • oceanbase.DBA_MVREF_STATS_PARAMS
          • oceanbase.DBA_MVREF_STATS_SYS_DEFAULTS
          • oceanbase.DBA_MVREF_STMT_STATS
          • oceanbase.DBA_OB_ACCESS_POINT
          • oceanbase.DBA_OB_ARCHIVE_DEST
          • oceanbase.DBA_OB_ARCHIVELOG
          • oceanbase.DBA_OB_ARCHIVELOG_PIECE_FILES
          • oceanbase.DBA_OB_ARCHIVELOG_SUMMARY
          • oceanbase.DBA_OB_AUTO_INCREMENT
          • DBA_OB_AUX_STATISTICS
          • oceanbase.DBA_OB_BACKUP_DELETE_JOB_HISTORY
          • oceanbase.DBA_OB_BACKUP_DELETE_JOBS
          • oceanbase.DBA_OB_BACKUP_DELETE_POLICY
          • oceanbase.DBA_OB_BACKUP_DELETE_TASK_HISTORY
          • oceanbase.DBA_OB_BACKUP_DELETE_TASKS
          • oceanbase.DBA_OB_BACKUP_JOB_HISTORY
          • oceanbase.DBA_OB_BACKUP_JOBS
          • oceanbase.DBA_OB_BACKUP_PARAMETER
          • oceanbase.DBA_OB_BACKUP_SET_FILES
          • oceanbase.DBA_OB_BACKUP_STORAGE_INFO
          • oceanbase.DBA_OB_BACKUP_STORAGE_INFO_HISTORY
          • oceanbase.DBA_OB_BACKUP_TASK_HISTORY
          • oceanbase.DBA_OB_BACKUP_TASKS
          • oceanbase.DBA_OB_BALANCE_JOB_HISTORY
          • oceanbase.DBA_OB_BALANCE_JOBS
          • oceanbase.DBA_OB_BALANCE_TASK_HISTORY
          • oceanbase.DBA_OB_BALANCE_TASKS
          • oceanbase.DBA_OB_CONCURRENT_LIMIT_SQL
          • oceanbase.DBA_OB_CCL_RULES
          • oceanbase.DBA_OB_CS_REPLICA_STATS
          • oceanbase.DBA_OB_DATA_DICTIONARY_IN_LOG
          • oceanbase.DBA_OB_DATABASE_PRIVILEGE
          • oceanbase.DBA_OB_DATABASES
          • oceanbase.DBA_OB_DEADLOCK_EVENT_HISTORY
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          • oceanbase.DBA_OB_EXTERNAL_TABLE_FILES
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          • oceanbase.DBA_OB_FREEZE_INFO
          • oceanbase.DBA_OB_IMPORT_TABLE_JOB_HISTORY
          • oceanbase.DBA_OB_IMPORT_TABLE_JOBS
          • oceanbase.DBA_OB_IMPORT_TABLE_TASK_HISTORY
          • oceanbase.DBA_OB_IMPORT_TABLE_TASKS
          • oceanbase.DBA_OB_KV_REDIS_TABLE
          • oceanbase.DBA_OB_KV_TTL_TASK_HISTORY
          • oceanbase.DBA_OB_KV_TTL_TASKS
          • oceanbase.DBA_OB_LOG_RESTORE_SOURCE
          • oceanbase.DBA_OB_LS
          • oceanbase.DBA_OB_LS_ARB_REPLICA_TASKS
          • oceanbase.DBA_OB_LS_ARB_REPLICA_TASK_HISTORY
          • oceanbase.DBA_OB_LS_HISTORY
          • oceanbase.DBA_OB_LS_LOCATIONS
          • oceanbase.DBA_OB_LS_LOG_ARCHIVE_PROGRESS
          • oceanbase.DBA_OB_LS_REPLICA_TASKS
          • oceanbase.DBA_OB_LS_REPLICA_TASK_HISTORY
          • oceanbase.DBA_OB_MAJOR_COMPACTION
          • oceanbase.DBA_OB_OUTLINE_CONCURRENT_HISTORY
          • oceanbase.DBA_OB_OUTLINES
          • oceanbase.DBA_OB_RECOVER_TABLE_JOB_HISTORY
          • oceanbase.DBA_OB_RECOVER_TABLE_JOBS
          • oceanbase.DBA_OB_SERVICES
          • oceanbase.DBA_OB_RESTORE_HISTORY
          • oceanbase.DBA_OB_RESTORE_PROGRESS
          • oceanbase.DBA_OB_RSRC_IO_DIRECTIVES
          • oceanbase.DBA_OB_RSRC_DIRECTIVES
          • oceanbase.DBA_OB_SENSITIVE_COLUMNS
          • oceanbase.DBA_OB_SENSITIVE_RULE_PLAINACCESS_USERS
          • oceanbase.DBA_OB_SENSITIVE_RULES
          • oceanbase.DBA_OB_SEQUENCE_OBJECTS
          • oceanbase.DBA_OB_STORAGE_IO_USAGE
          • oceanbase.DBA_OB_SYS_VARIABLES
          • oceanbase.DBA_OB_TABLE_LOCATIONS
          • oceanbase.DBA_OB_TABLE_OPT_STAT_GATHER_HISTORY
          • oceanbase.DBA_OB_TABLE_STAT_STALE_INFO
          • oceanbase.DBA_OB_TABLEGROUP_PARTITIONS
          • oceanbase.DBA_OB_TABLEGROUP_SUBPARTITIONS
          • oceanbase.DBA_OB_TABLEGROUP_TABLES
          • oceanbase.DBA_OB_TABLEGROUPS
          • oceanbase.DBA_OB_TABLET_REPLICAS
          • oceanbase.DBA_OB_TABLE_SPACE_USAGE
          • oceanbase.DBA_OB_TABLET_TO_LS
          • oceanbase.DBA_OB_TASK_OPT_STAT_GATHER_HISTORY
          • oceanbase.DBA_OB_TENANT_EVENT_HISTORY
          • oceanbase.DBA_OB_TENANTS
          • oceanbase.DBA_OB_TEMP_FILES
          • oceanbase.DBA_OB_TRANSFER_PARTITION_TASKS
          • oceanbase.DBA_OB_TRANSFER_PARTITION_TASK_HISTORY
          • oceanbase.DBA_OB_TRANSFER_TASK_HISTORY
          • oceanbase.DBA_OB_TRANSFER_TASKS
          • oceanbase.DBA_OB_USER_DEFINED_RULES
          • oceanbase.DBA_OB_USERS
          • oceanbase.DBA_OB_VECTOR_INDEX_TASKS
          • oceanbase.DBA_OB_VECTOR_INDEX_TASK_HISTORY
          • oceanbase.DBA_OB_ZONE_MAJOR_COMPACTION
          • oceanbase.DBA_OBJECTS
          • oceanbase.DBA_PART_COL_STATISTICS
          • oceanbase.DBA_PART_HISTOGRAMS
          • oceanbase.DBA_PART_INDEXES
          • oceanbase.DBA_PART_KEY_COLUMNS
          • oceanbase.DBA_PART_TABLES
          • oceanbase.DBA_RECYCLEBIN
          • oceanbase.DBA_RSRC_CONSUMER_GROUPS
          • oceanbase.DBA_RSRC_GROUP_MAPPINGS
          • oceanbase.DBA_RSRC_PLAN_DIRECTIVES
          • oceanbase.DBA_RSRC_PLANS
          • oceanbase.DBA_SCHEDULER_JOBS
          • oceanbase.DBA_SCHEDULER_JOB_RUN_DETAILS
          • oceanbase.DBA_SCHEDULER_WINDOWS
          • oceanbase.DBA_SEQUENCES
          • oceanbase.DBA_SQL_MANAGEMENT_CONFIG
          • oceanbase.DBA_SQL_PLAN_BASELINES
          • oceanbase.DBA_SUBPART_COL_STATISTICS
          • oceanbase.DBA_SUBPART_HISTOGRAMS
          • oceanbase.DBA_SUBPART_KEY_COLUMNS
          • oceanbase.DBA_SUBPARTITION_TEMPLATES
          • oceanbase.DBA_TAB_COL_STATISTICS
          • oceanbase.DBA_TAB_HISTOGRAMS
          • oceanbase.DBA_TAB_MODIFICATIONS
          • oceanbase.DBA_TAB_PARTITIONS
          • oceanbase.DBA_TAB_STATISTICS
          • oceanbase.DBA_TAB_STATS_HISTORY
          • oceanbase.DBA_TAB_SUBPARTITIONS
          • oceanbase.DBA_WR_ACTIVE_SESSION_HISTORY
          • oceanbase.DBA_WR_CONTROL
          • oceanbase.DBA_WR_EVENT_NAME
          • oceanbase.DBA_WR_SNAPSHOT
          • oceanbase.DBA_WR_SQLSTAT
          • oceanbase.DBA_WR_SQLTEXT
          • oceanbase.DBA_WR_STATNAME
          • oceanbase.DBA_WR_SYS_TIME_MODEL
          • oceanbase.DBA_WR_SYSSTAT
          • oceanbase.DBA_WR_SYSTEM_EVENT
        • Performance views
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          • V$OB_MEMORY
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          • V$OB_RPC_INCOMING
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          • V$OB_PARAMETERS
          • V$OB_PLAN_CACHE_PLAN_EXPLAIN
          • V$OB_PLAN_CACHE_PLAN_STAT
          • V$OB_PLAN_CACHE_STAT
          • V$OB_PROCESSLIST
          • V$OB_PS_ITEM_INFO
          • V$OB_PS_STAT
          • V$OB_PX_P2P_DATAHUB
          • V$OB_PX_TARGET_MONITOR
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          • V$OB_QUERY_RESPONSE_TIME_HISTOGRAM
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          • V$RSRC_PLAN
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          • V$OB_SESS_TIME_MODEL
          • V$OB_SESSION
          • V$SESSION_EVENT
          • V$OB_SHARED_STORAGE_QUOTA
          • V$OB_SQL_AUDIT
          • V$OB_SQL_CCL_STATUS
          • V$SQL_JOIN_FILTER
          • V$OB_SQL_PLAN
          • V$OB_SQL_WORKAREA_MEMORY_INFO
          • V$OB_SQLSTAT
          • V$OB_SSTABLES
          • V$OB_SS_LOCAL_CACHE
          • V$OB_STORAGE_CACHE_TASKS
          • V$OB_SYS_TIME_MODEL
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          • V$OB_TABLET_LOCAL_CACHE
          • V$OB_TENANT_MEMORY
          • V$OB_TENANT_RESOURCE_LIMIT
          • V$OB_TENANT_RESOURCE_LIMIT_DETAIL
          • V$OB_TIMESTAMP_SERVICE
          • V$OB_TRANSACTION_PARTICIPANTS
          • V$OB_TRANSACTION_SCHEDULERS
          • V$OB_UNITS
          • V$OB_VECTOR_MEMORY
          • V$RESTORE_POINT
          • V$SESSION_LONGOPS
          • V$SESSION_WAIT
          • V$SESSION_WAIT_HISTORY
          • V$SESSTAT
          • V$SQL_MONITOR_STATNAME
          • V$SQL_PLAN_MONITOR
          • V$SQL_WORKAREA
          • V$SQL_WORKAREA_ACTIVE
          • V$SQL_WORKAREA_HISTOGRAM
          • V$STATNAME
          • V$SYSSTAT
          • V$SYSTEM_EVENT
          • V$OB_ARBITRATION_MEMBER_INFO
          • V$OB_ARBITRATION_SERVICE_STATUS
          • V$OB_LOCKS
          • V$OB_OPT_STAT_GATHER_MONITOR
          • V$OB_THREAD
      • Oracle tenant views
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          • DBA_OB_BACKUP_DELETE_POLICY
          • DBA_OB_BACKUP_DELETE_TASK_HISTORY
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          • DBA_OB_BACKUP_TASK_HISTORY
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          • DBA_OB_BALANCE_JOB_HISTORY
          • DBA_OB_BALANCE_JOBS
          • DBA_OB_BALANCE_TASK_HISTORY
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          • DBA_OB_CONCURRENT_LIMIT_SQL
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          • DBA_OB_IMPORT_TABLE_TASKS
          • DBA_OB_LOG_RESTORE_SOURCE
          • DBA_OB_LS
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          • DBA_OB_LS_ARB_REPLICA_TASK_HISTORY
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          • DBA_OB_LS_REPLICA_TASK_HISTORY
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          • USER_ARGUMENTS
          • USER_AUDIT_OBJECT
          • USER_AUDIT_SESSION
          • USER_AUDIT_STATEMENT
          • USER_AUDIT_TRAIL
          • USER_COL_COMMENTS
          • USER_COL_PRIVS
          • USER_COLL_TYPES
          • USER_CONS_COLUMNS
          • USER_CONSTRAINTS
          • USER_DB_LINKS
          • USER_DEPENDENCIES
          • USER_ERRORS
          • USER_IND_COLUMNS
          • USER_IND_EXPRESSIONS
          • USER_IND_PARTITIONS
          • USER_IND_STATISTICS
          • USER_IND_SUBPARTITIONS
          • USER_INDEXES
          • USER_PLSQL_TYPES
          • USER_PLSQL_COLL_TYPES
          • USER_PLSQL_TYPE_ATTRS
          • USER_JOBS
          • USER_MVIEW_LOGS
          • USER_MVIEWS
          • USER_MVREF_CHANGE_STATS
          • USER_MVREF_RUN_STATS
          • USER_MVREF_STATS
          • USER_MVREF_STATS_PARAMS
          • USER_MVREF_STATS_SYS_DEFAULTS
          • USER_MVREF_STMT_STATS
          • USER_OBJECTS
          • USER_OB_SOURCE
          • USER_PART_COL_STATISTICS
          • USER_PART_HISTOGRAMS
          • USER_PART_INDEXES
          • USER_PART_KEY_COLUMNS
          • USER_PART_TABLES
          • USER_POLICIES
          • USER_POLICY_CONTEXTS
          • USER_POLICY_GROUPS
          • USER_PROCEDURES
          • USER_PROFILES
          • USER_RECYCLEBIN
          • USER_ROLE_PRIVS
          • USER_SCHEDULER_JOB_ARGS
          • USER_SCHEDULER_PROGRAM_ARGS
          • USER_SEC_RELEVANT_COLS
          • USER_SEGMENTS
          • USER_SEQUENCES
          • USER_SOURCE
          • USER_SUBPART_COL_STATISTICS
          • USER_SUBPART_HISTOGRAMS
          • USER_SUBPART_KEY_COLUMNS
          • USER_SUBPARTITION_TEMPLATES
          • USER_SYNONYMS
          • USER_SYS_PRIVS
          • USER_TAB_COL_STATISTICS
          • USER_TAB_COLS
          • USER_TAB_COLUMNS
          • USER_TAB_COMMENTS
          • USER_TAB_HISTOGRAMS
          • USER_TAB_MODIFICATIONS
          • USER_TAB_PARTITIONS
          • USER_TAB_PRIVS
          • USER_TAB_STATISTICS
          • USER_TAB_STATS_HISTORY
          • USER_TAB_SUBPARTITIONS
          • USER_TABLES
          • USER_TABLESPACES
          • USER_TRIGGER_ORDERING
          • USER_TRIGGERS
          • USER_TYPE_ATTRS
          • USER_TYPE_METHODS
          • USER_TYPES
          • USER_USERS
          • USER_VIEWS
        • Performance views
          • GV$ACTIVE_SESSION_HISTORY
          • GV$DBLINK
          • GV$DML_STATS
          • GV$GLOBAL_TRANSACTION
          • GV$INSTANCE
          • GV$OB_ACTIVE_SESSION_HISTORY
          • GV$OB_ARBITRATION_MEMBER_INFO
          • GV$OB_COMPACTION_DIAGNOSE_INFO
          • GV$OB_COMPACTION_PROGRESS
          • GV$OB_COMPACTION_SUGGESTIONS
          • GV$OB_CGROUP_CONFIG
          • GV$OB_DTL_INTERM_RESULT_MONITOR
          • GV$OB_FLT_TRACE_CONFIG
          • GV$OB_FUNCTION_IO_STAT
          • GV$OB_GLOBAL_TRANSACTION
          • GV$OB_GROUP_IO_STAT
          • GV$OB_KVCACHE
          • GV$OB_LOG_STAT
          • GV$OB_LOG_TRANSPORT_DEST_STAT
          • GV$OB_LS_SNAPSHOTS
          • GV$OB_MEMORY
          • GV$OB_MEMSTORE
          • GV$OB_MEMSTORE_INFO
          • GV$OB_NIC_INFO
          • GV$OB_OPT_STAT_GATHER_MONITOR
          • GV$OB_PARAMETERS
          • GV$OB_PLAN_CACHE_PLAN_EXPLAIN
          • GV$OB_PL_CACHE_OBJECT
          • GV$OB_PLAN_CACHE_PLAN_STAT
          • GV$OB_PLAN_CACHE_STAT
          • GV$OB_PROCESSLIST
          • GV$OB_PS_ITEM_INFO
          • GV$OB_PS_STAT
          • GV$OB_PX_P2P_DATAHUB
          • GV$OB_PX_TARGET_MONITOR
          • GV$OB_PX_WORKER_STAT
          • GV$OB_QUERY_RESPONSE_TIME_HISTOGRAM
          • GV$OB_RES_MGR_SYSSTAT
          • GV$OB_SERVER_SCHEMA_INFO
          • GV$OB_SESS_TIME_MODEL
          • GV$OB_SESSION
          • GV$OB_SHARED_STORAGE_QUOTA
          • GV$OB_SQL_AUDIT
          • GV$OB_SQL_CCL_STATUS
          • GV$SQL_JOIN_FILTER
          • GV$OB_SQL_PLAN
          • GV$OB_SQL_WORKAREA_MEMORY_INFO
          • GV$OB_SQLSTAT
          • GV$OB_SSTABLES
          • GV$OB_SS_LOCAL_CACHE
          • GV$OB_SYS_TIME_MODEL
          • GV$OB_TABLET_COMPACTION_HISTORY
          • GV$OB_TABLET_COMPACTION_PROGRESS
          • GV$OB_TENANT_MEMORY
          • GV$OB_TENANT_RESOURCE_LIMIT
          • GV$OB_TENANT_RESOURCE_LIMIT_DETAIL
          • GV$OB_TRANSACTION_PARTICIPANTS
          • GV$OB_TRANSACTION_SCHEDULERS
          • GV$OB_UNITS
          • GV$OB_RESULT_CACHE_OBJECTS
          • GV$OPEN_CURSOR
          • GV$SESSION_WAIT
          • GV$SESSION_WAIT_HISTORY
          • GV$SESSTAT
          • GV$SQL_PLAN_MONITOR
          • GV$SQL_WORKAREA
          • GV$SQL_WORKAREA_ACTIVE
          • GV$SQL_WORKAREA_HISTOGRAM
          • GV$SYSSTAT
          • GV$SYSTEM_EVENT
          • GV$OB_ARBITRATION_SERVICE_STATUS
          • GV$OB_LOCKS
          • GV$OB_THREAD
          • V$ACTIVE_SESSION_HISTORY
          • V$DBLINK
          • V$DML_STATS
          • V$OB_ENCRYPTED_TABLES
          • V$ENCRYPTED_TABLESPACES
          • V$EVENT_NAME
          • V$GLOBAL_TRANSACTION
          • V$GLOBALCONTEXT
          • V$INSTANCE
          • V$OB_MEMORY
          • V$OB_MEMSTORE
          • V$NLS_PARAMETERS
          • V$OB_ACTIVE_SESSION_HISTORY
          • V$OB_ARBITRATION_MEMBER_INFO
          • V$OB_ARCHIVE_DEST_STATUS
          • V$OB_COMPACTION_DIAGNOSE_INFO
          • V$OB_COMPACTION_PROGRESS
          • V$OB_COMPACTION_SUGGESTIONS
          • V$OB_CGROUP_CONFIG
          • V$OB_DTL_INTERM_RESULT_MONITOR
          • V$OB_DYNAMIC_PARTITION_TABLES
          • V$OB_FUNCTION_IO_STAT
          • V$OB_GLOBAL_TRANSACTION
          • V$OB_GROUP_IO_STAT
          • V$OB_KVCACHE
          • V$OB_LOG_STAT
          • V$OB_LOG_TRANSPORT_DEST_STAT
          • V$OB_LS_LOG_RESTORE_STATUS
          • V$OB_LS_SNAPSHOTS
          • V$OB_MEMSTORE_INFO
          • V$OB_NIC_INFO
          • V$OB_OPT_STAT_GATHER_MONITOR
          • V$OB_PARAMETERS
          • V$OB_PL_CACHE_OBJECT
          • V$OB_PROCESSLIST
          • V$OB_PX_P2P_DATAHUB
          • V$OB_PX_TARGET_MONITOR
          • V$OB_PX_WORKER_STAT
          • V$OB_QUERY_RESPONSE_TIME_HISTOGRAM
          • V$OB_RES_MGR_SYSSTAT
          • V$OB_RESULT_CACHE_OBJECTS
          • V$OB_SERVER_SCHEMA_INFO
          • V$OB_SESS_TIME_MODEL
          • V$OB_SESSION
          • V$OB_SHARED_STORAGE_QUOTA
          • V$OB_SQL_PLAN
          • V$OB_SQL_WORKAREA_MEMORY_INFO
          • V$OB_SQLSTAT
          • V$OB_SS_LOCAL_CACHE
          • V$OB_SYS_TIME_MODEL
          • V$OB_TABLET_COMPACTION_HISTORY
          • V$OB_TABLET_COMPACTION_PROGRESS
          • V$OB_TENANT_RESOURCE_LIMIT
          • V$OB_TENANT_RESOURCE_LIMIT_DETAIL
          • V$OB_TIMESTAMP_SERVICE
          • V$OB_TRANSACTION_PARTICIPANTS
          • V$OB_TRANSACTION_SCHEDULERS
          • V$OB_UNITS
          • V$OPEN_CURSOR
          • V$OB_PLAN_CACHE_PLAN_EXPLAIN
          • V$OB_PLAN_CACHE_PLAN_STAT
          • V$OB_PLAN_CACHE_STAT
          • V$OB_PS_ITEM_INFO
          • V$OB_PS_STAT
          • V$RSRC_PLAN
          • V$SESSION_WAIT
          • V$SESSION_WAIT_HISTORY
          • V$SESSTAT
          • V$OB_SQL_AUDIT
          • V$OB_SQL_CCL_STATUS
          • V$SQL_JOIN_FILTER
          • V$SQL_MONITOR_STATNAME
          • V$SQL_PLAN_MONITOR
          • V$SQL_WORKAREA
          • V$SQL_WORKAREA_ACTIVE
          • V$SQL_WORKAREA_HISTOGRAM
          • V$OB_SSTABLES
          • V$RESTORE_POINT
          • V$STATNAME
          • V$SYSSTAT
          • V$SYSTEM_EVENT
          • V$OB_TENANT_MEMORY
          • V$TIMEZONE_NAMES
          • V$VERSION
          • V$OB_ARBITRATION_SERVICE_STATUS
          • V$OB_LOCKS
          • V$OB_LS_REPLICA_TASK_PLAN
          • V$OB_THREAD
      • Description of common statistical events
      • General wait events
    • Parameters and system variables
      • Overview
      • Changes in V3.x and V4.x
      • Parameters
        • Overview of parameters
        • Cluster-level parameters
          • alert_log_level
          • all_cluster_list
          • all_server_list
          • arbitration_degradation_policy
          • auto_broadcast_location_cache_rate_limit
          • auto_leader_switch_interval
          • auto_refresh_location_cache_rate_limit
          • autoinc_cache_refresh_interval
          • backup_backup_dest
          • backup_backup_dest_option
          • backup_concurrency
          • backup_dest
          • backup_dest_option
          • backup_log_archive_option
          • backup_net_limit
          • backup_recovery_window
          • backup_region
          • backup_zone
          • balance_blacklist_failure_threshold
          • balance_blacklist_retry_interval
          • balancer_emergency_percentage
          • balancer_log_interval
          • balancer_task_timeout
          • balancer_timeout_check_interval
          • balancer_tolerance_percentage
          • bf_cache_miss_count_threshold
          • bf_cache_priority
          • builtin_db_data_verify_cycle
          • cache_wash_threshold
          • clog_cache_priority
          • clog_disk_usage_limit_percentage
          • clog_disk_utilization_threshold
          • clog_expire_days
          • clog_io_isolation_mode
          • clog_sync_time_warn_threshold
          • clog_transport_compress_func
          • cluster
          • cluster_id
          • config_additional_dir
          • cpu_count
          • cpu_reserved
          • data_copy_concurrency
          • data_dir
          • data_disk_usage_limit_percentage
          • data_disk_write_limit_percentage
          • data_storage_error_tolerance_time
          • data_storage_warning_tolerance_time
          • datafile_disk_percentage
          • datafile_maxsize
          • datafile_next
          • datafile_size
          • dead_socket_detection_timeout
          • debug_sync_timeout
          • default_compress
          • default_compress_func
          • default_row_format
          • default_transport_compress_func
          • devname
          • diag_syslog_per_error_limit
          • disk_io_thread_count
          • dtl_buffer_size
          • election_blacklist_interval
          • election_cpu_quota
          • _enable_add_fulltext_index_to_existing_table
          • enable_asan_for_memory_context
          • enable_async_syslog
          • enable_auto_leader_switch
          • enable_auto_refresh_location_cache
          • enable_cgroup
          • enable_dblink
          • enable_ddl
          • enable_election_group
          • enable_global_background_resource_isolation
          • enable_global_freeze_trigger
          • enable_log_archive
          • enable_major_freeze
          • enable_manual_merge
          • enable_merge_by_turn
          • enable_ob_esi_process
          • enable_ob_ratelimit
          • enable_one_phase_commit
          • enable_perf_event
          • enable_pg
          • enable_record_trace_id
          • enable_record_trace_log
          • enable_rereplication
          • enable_rich_error_msg
          • enable_rootservice_standalone
          • enable_rpc_authentication_bypass
          • enable_separate_sys_clog
          • enable_smooth_leader_switch
          • enable_sql_audit
          • enable_sql_operator_dump
          • enable_sys_table_ddl
          • enable_sys_unit_standalone
          • enable_syslog_recycle
          • enable_syslog_wf
          • enable_tcp_keepalive
          • enable_upgrade_mode
          • fast_recovery_concurrency
          • flush_log_at_trx_commit
          • fuse_row_cache_priority
          • gc_wait_archive
          • get_leader_candidate_rpc_timeout
          • global_background_cpu_quota
          • global_index_build_single_replica_timeout
          • global_major_freeze_residual_memory
          • global_write_halt_residual_memory
          • high_priority_net_thread_count
          • ignore_replay_checksum_error
          • ignore_replica_checksum_error
          • ilog_index_expire_time
          • index_block_cache_priority
          • index_cache_priority
          • index_clog_cache_priority
          • index_info_block_cache_priority
          • internal_sql_execute_timeout
          • large_query_threshold
          • large_query_worker_percentage
          • leak_mod_to_check
          • lease_time
          • local_ip
          • location_cache_cpu_quota
          • location_cache_expire_time
          • location_cache_priority
          • location_cache_refresh_min_interval
          • location_cache_refresh_rpc_timeout
          • location_cache_refresh_sql_timeout
          • location_fetch_concurrency
          • location_refresh_thread_count
          • log_archive_batch_buffer_limit
          • log_archive_checkpoint_interval
          • log_disk_percentage
          • log_disk_size
          • log_storage_warning_tolerance_time
          • ls_meta_table_check_interval
          • max_kept_major_version_number
          • max_px_worker_count
          • max_string_print_length
          • max_syslog_file_count
          • memory_chunk_cache_size
          • memory_limit
          • memory_limit_percentage
          • memory_reserved
          • memstore_limit_percentage
          • merge_stat_sampling_ratio
          • merge_thread_count
          • merger_completion_percentage
          • merger_switch_leader_duration_time
          • merger_warm_up_duration_time
          • micro_block_merge_verify_level
          • migrate_concurrency
          • migration_disable_time
          • min_observer_version
          • minor_deferred_gc_time
          • minor_freeze_times
          • minor_merge_concurrency
          • minor_warm_up_duration_time
          • multiblock_read_gap_size
          • multiblock_read_size
          • mysql_port
          • net_thread_count
          • ob_esi_io_concurrency
          • ob_esi_max_syslog_file_count
          • ob_esi_memory_limit
          • ob_esi_rpc_port
          • ob_esi_session_timeout
          • ob_esi_syslog_level
          • ob_event_history_recycle_interval
          • ob_ratelimit_stat_period
          • ob_startup_mode
          • obconfig_url
          • observer_id
          • ob_storage_s3_url_encode_type
          • ob_enable_java_env
          • ob_java_home
          • ob_java_connector_path
          • ob_java_opts
          • ofs_list
          • opt_tab_stat_cache_priority
          • partition_table_check_interval
          • plan_cache_evict_interval
          • plan_cache_high_watermark
          • plan_cache_low_watermark
          • px_task_size
          • px_workers_per_cpu_quota
          • rdma_io_thread_count
          • rebuild_replica_data_lag_threshold
          • recyclebin_object_expire_time
          • replica_safe_remove_time
          • resource_hard_limit
          • resource_soft_limit
          • restore_concurrency
          • rootservice_async_task_queue_size
          • rootservice_async_task_thread_count
          • rootservice_list
          • rootservice_memory_limit
          • rootservice_ready_check_interval
          • row_compaction_update_limit
          • row_purge_thread_count
          • rpc_client_authentication_method
          • rpc_port
          • rpc_server_authentication_method
          • rpc_timeout
          • schema_history_expire_time
          • schema_history_recycle_interval
          • server_balance_cpu_mem_tolerance_percent
          • server_balance_critical_disk_waterlevel
          • server_balance_disk_tolerance_percent
          • server_check_interval
          • server_cpu_quota_max
          • server_cpu_quota_min
          • server_data_copy_in_concurrency
          • server_data_copy_out_concurrency
          • server_permanent_offline_time
          • sql_audit_memory_limit
          • sql_login_thread_count
          • sql_net_thread_count
          • sql_protocol_min_tls_version
          • ssl_client_authentication
          • ssl_external_kms_info
          • stack_size
          • standby_fetch_log_bandwidth_limit
          • storage_meta_cache_priority
          • strict_check_os_params
          • switchover_process_thread_count
          • sync_io_thread_count
          • sys_bkgd_io_high_percentage
          • sys_bkgd_io_low_percentage
          • sys_bkgd_migration_change_member_list_timeout
          • sys_bkgd_migration_retry_num
          • sys_bkgd_net_percentage
          • sys_cpu_limit_trigger
          • syslog_compress_func
          • syslog_disk_size
          • syslog_file_uncompressed_count
          • syslog_io_bandwidth_limit
          • syslog_level
          • system_cpu_quota
          • system_memory
          • system_trace_level
          • tableapi_transport_compress_func
          • tablet_ls_cache_priority
          • tablet_meta_table_check_interval
          • tablet_meta_table_scan_batch_count
          • tablet_size
          • tcp_keepcnt
          • tcp_keepidle
          • tcp_keepintvl
          • tenant_cpu_variation_per_server
          • tenant_groups
          • tenant_task_queue_size
          • token_reserved_percentage
          • trace_log_sampling_interval
          • trace_log_slow_query_watermark
          • trx_2pc_retry_interval
          • trx_force_kill_threshold
          • trx_try_wait_lock_timeout
          • unit_balance_resource_weight
          • unit_gc_wait_time
          • use_large_pages
          • user_block_cache_priority
          • user_iort_up_percentage
          • user_row_cache_priority
          • user_tab_col_stat_cache_priority
          • virtual_table_location_cache_expire_time
          • wait_leader_batch_count
          • weak_read_version_refresh_interval
          • workers_per_cpu_quota
          • zone
          • zone_merge_concurrency
          • zone_merge_order
          • zone_merge_timeout
        • Tenant-level parameters
          • arbitration_timeout
          • archive_lag_target
          • approx_count_distinct_precision
          • audit_log_buffer_size
          • audit_log_compression
          • audit_log_enable
          • audit_log_format
          • audit_log_max_size
          • audit_log_path
          • audit_log_prune_seconds
          • audit_log_query_sql
          • audit_log_rotate_on_size
          • audit_log_strategy
          • audit_sys_operations
          • audit_trail
          • auto_split_tablet_size
          • backup_data_file_size
          • balancer_idle_time
          • choose_migration_source_policy
          • clog_max_unconfirmed_log_count
          • clog_persistence_compress_func
          • compaction_dag_cnt_limit
          • compaction_high_thread_score
          • compaction_low_thread_score
          • compaction_mid_thread_score
          • compaction_schedule_tablet_batch_cnt
          • compatible
          • connection_control_failed_connections_threshold
          • connection_control_max_connection_delay
          • connection_control_min_connection_delay
          • cpu_quota_concurrency
          • ddl_thread_score
          • default_auto_increment_mode
          • default_enable_extended_rowid
          • default_load_mode
          • default_progressive_merge_num
          • default_skip_index_level
          • default_storage_cache_policy
          • default_table_merge_engine
          • default_table_organization
          • default_table_store_format
          • direct_load_allow_fallback
          • dump_data_dictionary_to_log_interval
          • enable_adaptive_plan_cache
          • enable_auto_split
          • enable_clog_persistence_compress
          • enable_early_lock_release
          • enable_kv_group_commit
          • enable_kv_ttl
          • enable_lock_priority
          • enable_manual_storage_cache_policy
          • enable_mlog_auto_maintenance
          • enable_monotonic_weak_read
          • enable_mv_binlog_minimal_mode
          • enable_rebalance
          • enable_sql_extension
          • enable_transfer
          • enable_user_defined_rewrite_rules
          • enable_ps_parameterize
          • external_kms_info
          • freeze_trigger_percentage
          • global_index_auto_split_policy
          • ha_high_thread_score
          • ha_low_thread_score
          • ha_mid_thread_score
          • io_category_config
          • job_queue_processes
          • json_document_max_depth
          • kv_ttl_duty_duration
          • kv_group_commit_batch_size
          • kv_group_commit_rw_mode
          • kv_hbase_client_scanner_timeout_period
          • kv_ttl_history_recycle_interval
          • load_vector_index_on_follower
          • lob_enable_block_cache_threshold
          • log_archive_concurrency
          • log_disk_throttling_maximum_duration
          • log_disk_throttling_percentage
          • log_disk_utilization_limit_threshold
          • log_disk_utilization_threshold
          • log_restore_concurrency
          • log_storage_compress_all
          • log_storage_compress_func
          • log_transport_compress_all
          • log_transport_compress_func
          • ls_gc_delay_time
          • major_compact_trigger
          • major_freeze_duty_time
          • max_partition_num
          • max_stale_time_for_weak_consistency
          • merger_check_interval
          • minor_compact_trigger
          • mlog_trim_interval
          • ob_compaction_schedule_interval
          • ob_enable_batched_multi_statement
          • ob_encoding_granularity
          • ob_proxy_readonly_transaction_routing_policy
          • ob_query_switch_leader_retry_timeout
          • ob_ssl_invited_common_names
          • ob_vector_memory_limit_percentage
          • open_cursors
          • optimizer_index_cost_adj
          • partition_balance_schedule_interval
          • plsql_code_type
          • plsql_debug
          • plsql_optimize_level
          • plsql_v2_compatibility
          • px_node_policy
          • package_state_sync_max_size
          • query_memory_limit_percentage
          • query_response_time_flush
          • query_response_time_range_base
          • query_response_time_stats
          • range_optimizer_max_mem_size
          • recover_table_concurrency
          • recover_table_dop
          • replica_parallel_migration_mode
          • result_cache_max_size
          • result_cache_max_result
          • ob_result_cache_evict_percentage
          • ob_deterministic_udf_cache_max_size
          • rpc_memory_limit_percentage
          • shared_log_retention
          • spill_compression_codec
          • sql_work_area
          • standby_db_fetch_log_rpc_timeout
          • standby_db_preferred_upstream_log_region
          • sts_credential
          • tde_method
          • tenant_sql_login_thread_count
          • tenant_sql_net_thread_count
          • temporary_file_max_disk_size
          • storage_rowsets_size
          • suspend_storage_cache_task
          • ttl_thread_score
          • undo_retention
          • vector_index_memory_saving_mode
          • vector_index_optimize_duty_time
          • workarea_size_policy
          • writing_throttling_maximum_duration
          • writing_throttling_trigger_percentage
      • System variables
        • System variable summary
        • Global variables
          • activate_all_roles_on_login
          • auto_increment_cache_size
          • auto_increment_increment
          • auto_increment_offset
          • autocommit
          • automatic_sp_privileges
          • binlog_row_image
          • block_encryption_mode
          • character_set_client
          • character_set_connection
          • cardinality_estimation_model
          • character_set_database
          • character_set_filesystem
          • character_set_results
          • character_set_server
          • character_set_system
          • collation_connection
          • collation_database
          • collation_server
          • connect_timeout
          • cte_max_recursion_depth
          • cursor_sharing
          • datadir
          • default_password_lifetime
          • default_storage_engine
          • div_precision_increment
          • error_on_overlap_time
          • event_scheduler
          • explicit_defaults_for_timestamp
          • ENABLE_OPTIMIZER_ROWGOAL
          • foreign_key_checks
          • group_concat_max_len
          • identity
          • init_connect
          • innodb_stats_persistent
          • innodb_strict_mode
          • interactive_timeout
          • license
          • lc_time_names
          • log_row_value_options
          • long_query_time
          • lower_case_table_names
          • max_allowed_packet
          • max_connections
          • max_sp_recursion_depth
          • max_user_connections
          • mview_refresh_dop
          • net_buffer_length
          • net_read_timeout
          • net_write_timeout
          • nls_calendar
          • nls_characterset
          • nls_comp
          • nls_currency
          • nls_date_format
          • nls_date_language
          • nls_dual_currency
          • nls_iso_currency
          • nls_length_semantics
          • nls_nchar_characterset
          • nls_nchar_conv_excp
          • nls_numeric_characters
          • nls_sort
          • nls_territory
          • nls_timestamp_format
          • nls_timestamp_tz_format
          • ob_bnl_join_cache_size
          • ob_compatibility_mode
          • ob_compatibility_control
          • ob_compatibility_version
          • ob_create_table_strict_mode
          • ob_default_lob_inrow_threshold
          • ob_default_replica_num
          • ob_early_lock_release
          • ob_enable_ps_parameter_anonymous_block
          • ob_enable_aggregation_pushdown
          • ob_enable_blk_nestedloop_join
          • ob_enable_hash_group_by
          • ob_enable_index_direct_select
          • ob_enable_jit
          • ob_enable_pl_cache
          • ob_enable_plan_cache
          • ob_enable_rich_error_msg
          • ob_enable_sql_audit
          • ob_enable_transformation
          • ob_enable_transmission_checksum
          • ob_enable_truncate_flashback
          • ob_global_debug_sync
          • ob_log_level
          • ob_max_read_stale_time
          • ob_pl_block_timeout
          • ob_plan_cache_evict_high_percentage
          • ob_plan_cache_evict_low_percentage
          • ob_plan_cache_percentage
          • ob_proxy_global_variables_version
          • ob_query_timeout
          • ob_read_consistency
          • ob_reserved_meta_memory_percentage
          • ob_route_policy
          • ob_sql_audit_percentage
          • ob_sql_work_area_percentage
          • ob_table_access_policy
          • ob_tcp_invited_nodes
          • ob_temp_tablespace_size_percentage
          • ob_timestamp_service
          • ob_trx_idle_timeout
          • ob_trx_lock_timeout
          • ob_trx_timeout
          • optimizer_capture_sql_plan_baselines
          • ob_security_version
          • optimizer_dynamic_sampling
          • optimizer_features_enable
          • optimizer_use_sql_plan_baselines
          • parallel_degree_limit
          • parallel_degree_policy
          • parallel_max_servers
          • parallel_min_scan_time_threshold
          • parallel_servers_target
          • performance_schema
          • plugin_dir
          • plsql_ccflags
          • pid_file
          • query_cache_size
          • plsql_optimize_level
          • port
          • query_cache_type
          • query_rewrite_enabled
          • query_rewrite_integrity
          • read_only
          • recyclebin
          • regexp_stack_limit
          • regexp_time_limit
          • resource_manager_plan
          • socket
          • runtime_bloom_filter_max_size
          • runtime_filter_max_in_num
          • runtime_filter_type
          • runtime_filter_wait_time_ms
          • secure_file_priv
          • server_uuid
          • sql_auto_is_null
          • sql_mode
          • sql_quote_show_create
          • sql_safe_updates
          • sql_select_limit
          • sql_throttle_current_priority
          • sql_throttle_network
          • sql_throttle_priority
          • sql_throttle_rt
          • SQL_TRANSPILER
          • sql_warnings
          • system_time_zone
          • time_zone
          • transaction_isolation
          • transaction_read_only
          • tx_isolation
          • tx_read_only
          • validate_password_check_user_name
          • validate_password_length
          • validate_password_mixed_case_count
          • validate_password_number_count
          • validate_password_policy
          • validate_password_special_char_count
          • version
          • version_comment
          • wait_timeout
        • Session-level variables
          • enable_sql_plan_monitor
          • is_result_accurate
          • last_insert_id
          • nls_language
          • ob_capability_flag
          • ob_enable_show_trace
          • ob_hnsw_ef_search
          • ob_ivf_nprobes
          • ob_last_schema_version
          • ob_org_cluster_id
          • ob_sparse_drop_ratio_search
          • ob_proxy_partition_hit
          • ob_proxy_set_trx_executed
          • ob_trace_info
          • optimizer_dynamic_sampling
          • timestamp
          • tracefile_identifier
    • Error codes
      • MySQL mode
        • Overview
        • 0001 to 3999
        • 4000 to 4499
        • 4500 to 4999
        • 5000 to 5999
        • 6000 to 6999
        • 7000 to 7999
        • 8000 to 8999
        • 9000 ~ 9499
        • 9500 to 9999
        • 10000 to 12000
        • 22998, 30926, 38104, and 38105
      • Oracle mode
        • Overview
        • OBE-00000 ~ OBE-00999
        • OBE-01000 to OBE-01499
        • OBE-01500 to OBE-01999
        • OBE-02000 to OBE-04999
        • OBE-05000 to OBE-10000
        • OBE-10000 to OBE-19999
        • OBE-20000 to OBE-29999
        • OBE-30000 to OBE-49999
        • OBE-50000 to OBE-99999
        • PLS-00000 to PLS-00999
    • Performance tuning
      • Overview
      • Performance related tools
        • System tools
          • Top
          • CPU tools
          • Memory tools
          • Disk I/O tools
          • Network tools
        • Internal tables
          • GV$SYSSTAT
          • GV$OB_SQL_AUDIT
          • GV$OB_TRANSACTION_PARTICIPANTS
        • Logs
          • slow trans
          • dump tenant info
          • Trace logs
        • OCP
      • System tuning
        • OS parameter tuning
        • Database parameter tuning
          • CPU parameters
          • I/O parameters
          • Memory-related parameters
          • Network transmission parameters
        • ODP parameter tuning
          • CPU parameters
          • Network transmission parameters
          • Routing parameters on nodes
      • Business model tuning
        • Load balancing
        • SQL diagnostics
        • Distributed transactions
      • Performance diagnosis
        • Monitor and diagnose the cluster performance
        • Diagnose tenant performance
        • Monitor ODP performance
        • Monitor host performance
        • WR management
          • Overview
          • Manage WR
          • Monitor historical session performance
          • Clean up WR data
        • ASH report
          • ASH
          • Generate an ASH report
          • Analyze the ASH report
      • SQL tuning
        • Execution process of SQL queries
        • SQL execution plans
          • Introduction to SQL execution plans
          • Fast parameterization
          • Plan cache
          • Execution plan operators
            • TABLE SCAN
            • JOIN
            • COUNT
            • GROUP BY
            • WINDOW FUNCTION
            • SUBPLAN FILTER
            • DISTINCT
            • SEQUENCE
            • MATERIAL
            • SORT
            • LIMIT
            • FOR UPDATE
            • SELECT INTO
            • SUBPLAN SCAN
            • UNION
            • INTERSECT
            • EXCEPT/MINUS
            • INSERT
            • DELETE
            • UPDATE
            • MERGE
            • EXCHANGE
            • GI
          • Real-time execution plan display
          • SQL optimization practice with EXPLAIN
        • Distributed execution plans
          • Perform distributed execution and parallel queries
          • Generate a distributed plan
          • Schedule distributed execution plans
          • Manage distributed execution plans
          • Parallel execution enabling methods and their priority
          • Auto DOP
          • Execute parallel queries
          • Perform parameter tuning for a parallel query
          • Parallel DML
          • Parallel DDL
        • Parallel execution plans
          • Introduction to parallel execution
          • Classification and optimization of parallel execution
          • Set concurrent execution
            • Concurrency control and queuing
            • Set a DOP for parallel execution
            • Set parallel execution parameters
          • Parallel execution diagnostics
          • Parallel execution tuning tips
          • Quick start
        • SQL tuning
          • Overview
          • General procedure
          • SQL execution performance monitoring
            • SQL audit
            • SQL Trace
            • Plan cache views
            • SQL performance analysis example
              • Use SQL Audit to analyze wait events in a query
              • Analyze SQL queries that cause an abrupt RT jitter
              • View and analyze the shape of an execution plan
              • Analyze slow SQL queries
              • Query SQL traffic distribution and QPS
              • Check whether SQL queries are balanced across servers in a cluster
              • Find the TOP N SQL queries
              • Analyze whether an unusually large number of remote execution requests exist in the system or the execution of an SQL statement
              • Find full table scan SQL statements in a tenant
              • Find the TOP N queries with the longest execution time within a certain period
              • Analyze queries related to distributed plans
              • Check whether the RPC execution count of a distributed subplan is balanced across servers in a cluster
          • Optimizer statistics
            • Overview of statistics
            • Statistics collection methods
              • Overview of methods for collecting statistics
              • Histograms
              • Manual statistics collection
              • Automatic statistics collection
              • Online statistics collection
              • Dynamic sampling
            • Statistics management
              • Overview
              • Delete statistics
              • Set statistics
              • Import and export statistics
              • Lock and unlock statistics
              • Manage statistics history
              • Manage statistics preferences
            • Collection and update strategies of statistics for partitioned tables
            • Monitoring and diagnostics for statistics collection
            • OceanBase statistics management practical guide
          • Query rewrite
            • Overview
            • Rule-based query rewrite
            • Cost-based query rewrite
          • Query optimization
            • Access path
              • Overview
              • Rule-based path selection
              • Cost-based path selection
            • Join algorithm
              • Overview
              • Join algorithms
              • Runtime filter
              • Join order
          • Manage execution plans
            • Optimizer hints
            • Plan binding
            • SPM plan management
        • Glossary
        • General issues in SQL tuning
    • Perform testing
      • OceanBase Sysbench testing
        • Run the Sysbench benchmark test with OceanBase Database
        • Sysbench test report of OceanBase Database
        • High-performance parameter configuration for OceanBase Sysbench
        • Analyze OceanBase Sysbench performance issues
      • OceanBase TPC-C testing
        • Run the TPC-C benchmark test with OceanBase Database
        • TPC-C test report of OceanBase Database
      • OceanBase TPC-DS testing
        • Run the TPC-DS benchmark test with OceanBase Database
        • TPC-DS test report of OceanBase Database
      • OceanBase TPC-H testing
        • Run the TPC-H benchmark test with OceanBase Database
        • TPC-H test report of OceanBase Database
    • Database proxy
      • OceanBase Database Proxy
      • Connection and routing
      • ODP
        • Overview
        • Manage ODP clusters
          • Create an ODP cluster
          • Manage ODP cluster parameters
          • Delete an ODP cluster
          • Upgrade all ODPs in an ODP cluster
          • Restart all ODPs in an ODP cluster
          • Manage OceanBase clusters connected to an ODP cluster
          • Monitor ODP cluster performance
        • Manage ODP
          • Add an ODP
          • Start an ODP
          • Refresh ODP configurations
          • Stop an ODP
          • Restart an ODP
          • Delete an ODP
          • Upgrade one or more ODPs
        • ODP startup parameters
      • Physical connections
      • Logical connection
        • Query all sessions
        • Query the details of a session
        • Query the metrics of a session
        • Query session variables
        • Terminate a server session
      • Route management
        • Table-based routing of ODP
        • LDC-based routing
        • ODP routing policy
          • Read/Write splitting
          • Follower-first read
          • Blocklist mechanism
          • Transaction routing
      • View tenant sessions
      • Terminate a tenant session
      • Set the maximum number of connections for a tenant
    • Drivers
      • ECOB
      • OBCI
      • OceanBase Connector/J
      • OceanBase Connector/C
      • OceanBase Connector/ODBC
    • Platforms
      • OMA
      • OMS
      • OCP
      • ODC
      • OAT
    • Components & tools
      • O&M management
        • obshell
          • Overview
          • Use cases
            • obshell management
              • Start or stop obshell
              • Upgrade obshell
            • cluster management
              • Deploy an OceanBase cluster
              • Take over an OceanBase cluster not deployed by obshell
              • Start an OceanBase cluster
              • Stop an OceanBase cluster
              • Use obshell to scale out an OceanBase cluster
              • Upgrade an OceanBase cluster
              • Initiate a cluster-level backup
            • Tenant management
              • Create a tenant
              • Initiate a tenant-level backup
              • Initiate tenant-level restore
              • Expand a tenant
            • Configure an OBServer node to start automatically on boot
          • obshell commands
            • Agent commands of obshell
            • Cluster commands of obshell
            • obshell unit commands
            • obshell resource pool commands
            • Tenant command group of obshell
            • Task commands of obshell
            • Backup commands in obshell
            • obshell restore command group
            • obshell recyclebin command group
          • API references
            • obshell API requests
            • Hybrid encryption for API operations
            • obshell management
              • AgentUpgradeCheck
              • UpgradeAgent
              • QueryNodeStatus
            • cluster management
              • AddNodeBeforeClusterInitialization
              • DeleteNodeBeforeClusterInitialization
              • SetClusterConfig
              • SetServerConfig
              • InitializeCluster
              • StartCluster
              • StopCluster
              • ObUpgradeCheck
              • UpgradeOb
              • AddNode
              • GetObInfo
            • Unit config management
              • Create a resource specification
              • Retrieve all resource specifications
              • Query the information of a specified resource specification
              • Delete a resource specification
            • Resource pool management
              • Get information about all resource pools
              • Delete a specified resource pool
            • Tenant management
              • Create a tenant
              • Query tenant information
              • Change the tenant password
              • Modify the access whitelist of a tenant
              • Modify the primary zone of a tenant
              • Modify tenant system variables
              • Modify tenant configurations
              • Rename a tenant
              • Delete a tenant
              • Add a tenant replica
              • Modify a tenant replica
              • Delete a tenant replica
              • Lock a tenant
              • Unlock a tenant
              • Get an overview of all tenants
              • Query a system variable of a specified tenant
              • Fuzzy query tenant system variables
              • Query a tenant parameter
              • Fuzzy query tenant parameters
            • Backup management
              • Set the backup configuration for a tenant
              • Set cluster-level backup configurations
              • Update the backup configuration of a tenant
              • Update the cluster-level backup configuration
              • Initiate a backup for a single tenant
              • Initiate a cluster-level backup
              • View information about a backup task for a tenant
              • View cluster-level backup tasks
              • Modify the backup status of a tenant
              • Modify the status of cluster-level backups
              • Modify the log archiving status of a tenant
              • Modify the log archiving status of a cluster
            • Restore management
              • Initiate tenant restore
              • View tenant recovery
              • Cancel tenant restore
            • Recycle bin management
              • Query all tenant information in the recycle bin
              • Restore a tenant from the recycle bin
              • Clear a tenant from the recycle bin
            • Task management
              • OperateDag
              • GetDagDetails
              • GetNodeDetails
              • GetSubtaskDetails
              • QueryUnfinishedTasks
              • QueryUnfinishedAgentTasks
              • QueryUnfinishedObTasks
              • QueryLastObTask
              • QueryLastAgentTask
            • Other APIs
              • UploadPkg
              • GetPublicKey
          • SDK references
            • Python
              • Quick start
              • obshell management
                • Perform an agent upgrade check
                • Upgrade agents
                • Query the status of a node
              • cluster management
                • Add a node before cluster initialization
                • Remove a node before cluster initialization
                • Set cluster-level configurations
                • Set server-level configurations
                • Initialize a cluster
                • Start a cluster
                • Stop a cluster
                • Perform an OceanBase Database upgrade check
                • Upgrade OceanBase Database
                • Scale out a cluster
                • Query the information about a cluster
                • Clean up obshell nodes in an uninitialized cluster
                • Create a cluster
              • Unit config management
                • Create a resource specification
                • Obtain information about all resource specifications
                • Query information about a specified resource unit
                • Delete a resource specification
              • Resource pool management
                • Get information about all resource pools
                • Delete a resource pool
              • Tenant management
                • Create a tenant
                • Query tenant information
                • Change the password of a tenant
                • Modify the access whitelist of a tenant
                • Modify the primary zone of a tenant
                • Modify tenant system variables
                • Modify tenant parameters
                • Rename a tenant
                • Drop a tenant
                • Add a tenant replica
                • Modify a tenant replica
                • Delete a tenant replica
                • Lock a tenant
                • Unlock a tenant
                • Query the overview of all tenants
                • Query tenant system variables
                • Query tenant configuration items
              • Backup management
                • Configure the backup settings for a tenant
                • Configure cluster-level backup settings
                • Update the backup configuration of a tenant
                • Update cluster-level backup configuration
                • Initiate a backup for a single tenant
                • Initiate a cluster-level backup
                • View a backup task of a tenant
                • View cluster-level tenant backup tasks
                • Modify the backup status of a tenant
                • Modify the status of cluster-level backups
                • Change the log archiving status of a tenant
                • Modify the log archiving status of a cluster
              • Restore management
                • Restore a single tenant
                • View tenant recovery
                • Cancel tenant restoration
              • Recycle bin management
                • Get information about all tenants in the recycle bin
                • Restore a tenant from the recycle bin
                • Purge a tenant from the recycle bin
              • Task management
                • Operate a task
                • Obtain the information about a task
                • Obtain the information about a node
                • Obtain the information about a subtask
                • Query all unfinished tasks
                • Query unfinished agent tasks
                • Query unfinished OceanBase cluster tasks
                • Query the last O&M task in an OceanBase cluster
                • Query the last O&M task of an obshell node
              • Other APIs
                • Upload an RPM package
            • GO
              • Quick Start with obshell-sdk-go
              • obshell management
                • Perform an agent upgrade check
                • Upgrade agents
                • Query the status of a node
              • cluster management
                • Add a node before cluster initialization
                • Remove a node before cluster initialization
                • Set cluster-level configurations
                • Set server-level configurations
                • Initialize a cluster
                • Start a cluster
                • Stop a cluster
                • Perform an OceanBase Database upgrade check
                • Upgrade OceanBase Database
                • Scale out a cluster
                • Query the information about a cluster
                • Clean up obshell nodes in an uninitialized cluster
                • Create a cluster
              • Unit config management
                • Create a resource unit configuration
                • Query all resource specifications
                • Query the specifications of a specified resource
                • Drop a resource unit configuration
              • Resource pool management
                • Get information about all resource pools
                • Drop a resource pool
              • Tenant management
                • Create a tenant
                • Query tenant information
                • Change a tenant password
                • Modify the tenant access whitelist
                • Modify the primary zone of a tenant
                • Modify tenant system variables
                • Modify tenant parameters
                • Rename a tenant
                • Drop a tenant
                • Add a tenant replica
                • Modify a tenant replica
                • Delete a tenant replica
                • Lock a tenant
                • Unlock a tenant
                • Query the overview of all tenants
                • Query tenant system variables
                • Query tenant configuration items
              • Backup management
                • Set the backup configuration for a tenant
                • Set the cluster-level backup configuration
                • Update the backup configuration for a tenant
                • Update the cluster-level backup configuration
                • Initiate a backup for a single tenant
                • Initiate a cluster-level backup
                • View a backup task for a tenant
                • View cluster-level tenant backup tasks
                • Modify the backup status of a tenant
                • Modify the status of a cluster-level backup
                • Change the log archiving status of a tenant
                • Modify the status of cluster-level log archiving
              • Restore management
                • Initiate a restore for a single tenant
                • View tenant recovery
                • Cancel tenant restore
              • Recycle bin management
                • Get information about all tenants in the recycle bin
                • Restore a tenant from the recycle bin
                • Purge tenants from the recycle bin
              • Task management
                • Operate a task
                • Obtain the information about a task
                • Obtain the information about a node
                • Obtain the information about a subtask
                • Query all unfinished tasks
                • Query unfinished agent tasks
                • Query unfinished OceanBase cluster tasks
                • Query the last O&M task in an OceanBase cluster
                • Query the last O&M task of an obshell node
              • Other APIs
                • Upload an RPM package
        • obd
        • ob_admin
          • Overview
          • clog
            • log_tool
            • Format of clogs
            • Transaction logs
          • Backup and restore
            • dump_backup
            • test_io_device
            • io_adapter_benchmark
          • dumpsst
        • ob-operator
        • ob_error
      • Monitoring and diagnostics
        • obdiag
        • sql_diagnoser
          • Overview
          • Install and use SQL diagnoser sql_diagnoser
            • Install sql_diagnoser
            • Use sql_diagnoser
          • sql_diagnoser parameters
            • Built-in diagnostic items
            • Diagnostic rule expression
            • API operations
            • Diagnostic items of SQL review
      • Log analysis
        • oblogminer
          • Overview
          • Install oblogminer
          • Command-line options
          • Examples
          • FAQ
      • Data integration
        • obloader and obdumper
        • oblogproxy
        • obcdc
          • OceanBase Binlog Service
          • obcdc parameters
            • Sample configuration file
            • General obcdc parameters
            • obcdc parameters
          • obcdc development instructions
          • obcdc_tailf
          • Throttling
          • obcdc allowlist and blocklist
          • Incremental direct load in obcdc
          • FAQ
      • Stress testing tools
        • mysqltest
          • Use obd.sh to run mysqltest
          • Use of cases
            • Add a test case
            • Test case writing conventions
            • General test case writing commands
    • OceanBase plugin
      • Overview of OceanBase plugin
      • Tokenizer plugin
  • FAQ
    • Products
    • FAQ about SQL statements
    • Deployment
    • Cluster management
    • High availability
    • FAQ about columnstores
  • Release Notes
    • Version number guidelines
    • OceanBase Database Enterprise Edition
      • V4.3
        • OceanBase Database Enterprise Edition V4.3.5
        • OceanBase Database Enterprise Edition V4.3.3
        • OceanBase Database Enterprise Edition V4.3.2
        • OceanBase Database Enterprise Edition V4.3.1
        • OceanBase Database Enterprise Edition V4.3.0
      • V4.2
        • OceanBase Database Enterprise Edition V4.2.5
        • OceanBase Database Enterprise Edition V4.2.1
        • OceanBase Database Enterprise Edition V4.2.0
      • V4.1
        • OceanBase Database Enterprise Edition V4.1.0
      • V3.2
        • OceanBase Database Enterprise Edition V3.2.4
        • OceanBase Database Enterprise Edition V3.2.3
        • OceanBase Database Enterprise Edition V3.2.2
        • OceanBase Database Enterprise Edition V3.2.1
        • OceanBase Database Enterprise Edition V3.2.0
      • V3.1
        • OceanBase Database Enterprise Edition V3.1.2
        • OceanBase Database Enterprise Edition V3.1.1
      • V2.2
        • OceanBase Database Enterprise Edition V2.2.77
        • OceanBase Database Enterprise Edition V2.2.76
        • OceanBase Database Enterprise Edition V2.2.30
    • OceanBase Database Community Edition
      • V4.3
        • OceanBase Database Community Edition V4.3.5
        • OceanBase Database Community Edition V4.3.3
        • OceanBase Database Community Edition V4.3.2
        • OceanBase Database Community Edition V4.3.1
        • OceanBase Database Community Edition V4.3.0
      • V4.2
        • OceanBase Database Community Edition V4.2.5
        • OceanBase Database Community Edition V4.2.1
        • OceanBase Database Community Edition V4.2.0
      • V4.1
        • OceanBase Database Community Edition V4.1.0
      • V4.0
        • OceanBase Database Community Edition V4.0.0
      • V3.1
        • OceanBase Database Community Edition V3.1.5
        • OceanBase Database Community Edition V3.1.4
        • OceanBase Database Community Edition V3.1.3
        • OceanBase Database Community Edition V3.1.2
        • OceanBase Database Community Edition V3.1.1
  • Glossary

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OceanBase Database Enterprise Edition V4.2.0

Last Updated:2025-06-03 09:37:49  Updated
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V4.2.0 BP1
Version information
Bug fixes
V4.2.0 Beta
Version information
Overview
Description of core features
Performance test report
Compatibility changes
Recommended versions of tools
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V4.2.0 BP1

Version information

  • Release date: September 14, 2023
  • Version: V4.2.0 BP1
  • RPM version: oceanbase-4.2.0.0-101000042023091319

Bug fixes

  • Fixed the issue where, in the Oracle mode, when the RS tenant and the regular tenant are not on the same server, Error 4013 may occur during SQL execution if memory allocation using the tenant ID is attempted on the RS server.

  • Fixed the correctness issue caused by the execution of the index skip scan plan when the full index suffix condition is not specified for parallel execution. For example, the index key is c1, c2, c3, but only c2 is specified and c3 is not specified.

  • Fixed the issue where explicit setting of _optimizer_better_inlist_costing=true for a specific tenant may cause core dump or other abnormal behavior after a restart.

  • Fixed the issue where after upgrading from V4.1.x to V4.2.x, incorrect maintenance of max_ls_id leads to prolonged execution times for business operations.

V4.2.0 Beta

Version information

  • Release date: August 2, 2023
  • Version: V4.2.0 Beta
  • Description: The Beta version resolved most of the issues and is becoming more and more stable. However, there may still be some minor issues or errors that need to be addressed in the final stable release, so we recommend that you use this version in a testing environment.

Overview

OceanBase Database V4.2.0 further enhanced the core features based on V4.1.0 and included all major functionalities of the V3.x series. It further improved product scalability, resource utilization, performance, compatibility, and ease of use. V4.2.x will serve as a long-term support (LTS) version.

Core features of V4.2.0 include:

  • MySQL compatibility

    • Function index: OceanBase Database already supports function-based indexes in earlier versions in Oracle mode. The MySQL mode of V4.2.0 now supports MySQL 8.0-compatible function-based indexes, further enhancing feature stability.
    • OBCDC: The new version now supports the output of row data according to the column definition sequence, meeting the compatibility requirements of MySQL Binlog Service. OBCDC no longer depends on the system tenant, but supports data synchronization with user tenants. This means that user tenants can use OBCDC on their own, without relying on the system tenant. V4.2.0 also supports data synchronization for tables without primary keys.
  • Oracle compatibility

    • LOCK TABLE: OceanBase Database provides LOCK TABLE syntaxes for Oracle tenants in V4.1.0 and earlier versions. However, many limitations on using the syntaxes exist. OceanBase Database V4.2.0 provides higher compatibility with LOCK TABLE syntaxes and enhances the features that are unavailable in earlier versions. Specifically, you can lock multiple tables, partitions, and subpartitions, and make the WAIT N and NOWAIT keywords take effect.
  • Multi-model support

    • Oracle XML: The XMLType data type is supported in Oracle mode. Nine XML expressions and basic XML creation, query, and modification capabilities are provided.
  • Performance improvements

    • Enhancement of optimizer/executor/procedural language (PL) capabilities: Enhanced the query rewriting and optimization capabilities, with a focus on improving the performance of executor operators. Optimized the plan cache and parallel execution logic for PL and supported SQL statements that return complex data types.
    • Statistics functionality enhancement: Enhanced the stability and availability of the statistics functionality, added the monitoring and diagnostic functionality for statistics collection, and optimized the performance and memory overhead of statistics collection.
    • Dynamic sampling: Supports dynamic sampling, allowing optimizers to collect statistical information during SQL execution and generate optimal execution plans. This helps to improve query performance.
    • Query plan evolution: Supports query plan evolution to avoid performance regression of execution plans.
    • Runtime Filter: Provided full support for Runtime Filter, improving the analytical processing (AP) performance.
    • Performance optimization under 4 CPU cores (4C): Optimized the performance in various OLTP scenarios by over 20% in 4C environments with default parameter settings.
    • Performance optimization of reading transaction data: Optimized the performance of querying transaction tables during the minor compaction of uncommitted data.
    • Parallel minor compaction of transaction data tables: OceanBase Database V4.1.0 already supports parallel MINOR_MERGE (combining multiple mini SSTables into a minor SSTable). V4.2.0 additionally supports parallel MINI_MERGE for transaction data tables (freezing the MemTable and converting it into a mini SSTable through minor compaction).
    • Fast generation of random data: Introduced the built-in function GENERATOR(N). This function can be used with random functions such as RANDOM([N]), RANDSTR(N, gen) and distribution control functions like NORMAL(<mean>, <stddev>, <gen>), UNIFORM(<min>, <max>, <gen>), and ZIPF(<s>, <N>, <gen>) to generate random data quickly. Compared with Oracle Connect By and MySQL Recursive CTE, OceanBase Table Generator has significant performance advantages.
  • OLAP capabilities

    • Read-only external tables: Supports the creation and reading of read-only external tables when performing online analytical processing (OLAP) operations, thereby reducing costs of loading or inserting data into databases.
  • Scalability enhancement

    • Transfer and load balancing: Uses the transfer technology to split and merge log streams, supporting data migration across nodes on a per-partition basis. This provides flexible scaling and dynamic data balancing capabilities.
    • Replicated tables: Reconstructed replicated tables based on the single-node log stream architecture. The new version introduced partition-based readable version number verification and log stream-based lease-granting mechanism to ensure the correctness of strong consistency reads. Additionally, this version improved the ability to switch leaders without killing transactions. This means that uncommitted replicated table transactions can continue to execute after a leader switch initiated by users or load balancing. Compared with V3.x, V4.2.0 has better write transaction performance, stronger disaster recovery capability for replicated tables, and lower impact on read operations in case of replica failure.
  • High availability enhancement

    • Physical standby database: OceanBase Database V4.1.0 introduced an archive-based primary/standby solution, offering flexible configuration without requiring network connection between primary and standby tenants. However, many scenarios still require a primary/standby solution based on direct network connection to reduce storage and network costs, and to simplify backup and restore operations. V4.2.0 extended support in these scenarios.
    • Log write throttling: When the speed of committing logs to the disk is greater than the minor compaction speed, the log disk will become full. In V4.2.0, when the log disk usage reaches a specified threshold, the speed of committing logs to the disk is limited, to minimize the occurrences that the log disk becomes full because of the high write pressure in the cluster. For more information, see the log_disk_throttling_percentage and log_disk_throttling_maximum_duration parameters.
  • Resource utilization optimization

    • Idle CPU optimization: Made optimizations for high-frequency, time-consuming SQL statements and background threads to reduce the CPU overhead of internal SQL execution and periodic execution of background threads. According to a test conducted on a single tenant in an idle environment (30 tables and a million rows of data per table), the default CPU overhead is around 0.2C.
    • On-demand expansion of disk data files: Supports progressive disk expansion, where an appropriate disk size is first pre-allocated and then automatically expanded based on actual usage.
    • Shared memory identification mechanism: Added a defense mechanism in the technical means to mark the code that is expected to use the shared memory and to optimize the situation where the shared resources increase with the code merge.
  • Usability enhancement

    • Auto degree of parallelism (DOP): Support for auto DOP to automatically calculate query parallelism, reducing the threshold for parallel execution.
    • End-to-end diagnostics enhancement: OceanBase Database V4.1.0 introduced end-to-end diagnostic capabilities, and V4.2.0 added some trace logging information based on the end-to-end diagnostic framework. This version also provides interactive Show Trace capabilities based on transactions and SQL queries.
    • Logical plan management: Made several improvements to make logical plans more user-friendly. These improvements include the ability to save EXPLAIN plan information, feedback on the execution of logical plans, and real-time plans for running SQL queries. Additionally, rich interfaces for the DBMS_XPLAN package were also provided to display plans for specific queries, baseline plans, and real-time session plans in a formatted manner.
    • Background thread statistics: Versions earlier than V4.2.0 tended to record front-end thread diagnosis information from a client perspective. However, for OceanBase Database, background threads constitute the vast majority. Therefore, it is necessary to learn about the state of background threads, both for troubleshooting issues and diagnosing performance. V4.2.0 adds the [G]V$OB_THREAD view to record the status information of all threads.
  • Security enhancement

    • Backup and restore for encryption-enabled tenants: OceanBase Database V4.1.0 does not support backup and restore for tenants that have enabled encryption. OceanBase Database V4.2.0 adapts the transparent data encryption (TDE) capability to the new backup and restore mechanism. You can separately back up the primary keys during the backup and specify the primary key backup information during the restore. Features such as backup and restore and the primary/standby databases are also supported for encrypted tenants.
  • National standards

    • GB18030-2022 character set: Provided support for GB18030-2022 character set since OceanBase Database V4.2.0. GB18030-2022 character set was released on July 19, 2022, and formally implemented on August 1, 2023. It supports more rare Chinese characters and minority languages, making it a mandatory standard for information systems.
  • Product forms

    • Standalone architecture-based primary/standby solution: OceanBase Database V4.1.0 introduced the standalone architecture, and V4.2.0 further expanded this architecture to include a primary/standby solution.
    • Read-only replicas (R replicas): OceanBase Database V4.2.0 introduced read-only replicas to provide read-only capabilities, which are different from full-featured replicas.

Description of core features

MySQL compatibility

Function index: MySQL 8.0 introduced the function-based index feature to optimize query performance. Typically, if a function or expression is used for a query column, a regular index cannot be used for optimization, and a function-based index is needed to improve query performance. Function index can use the return value of a function as part of the index, thereby speeding up query execution. Starting from V4.2.0, OceanBase Database supports MySQL 8.0-compatible function-based index under the MySQL tenant, and it can be created using statements such as CREATE TABLE, CREATE INDEX, and ALTER TABLE. In addition, V4.2.0 also enhances the index extraction capability and can effectively use indexes in most scenarios where there is implicit conversion outside the index expression, or the reference column on a prefix index has a LIKE predicate. For more information, see Create an index.

Oracle compatibility

LOCK TABLE: OceanBase Database provides LOCK TABLE syntaxes for Oracle tenants in V4.1.0 and earlier versions. You can lock a single table and make the WAIT N and NOWAIT keywords take effect. However, many limitations on using the syntaxes exist. For example, the LOCK TABLE statement can lock only a single table, but it cannot lock multiple tables or partitions. The WAIT N and NOWAIT keywords do not actually take effect. After you specify the WAIT N or NOWAIT keyword in a statement, the execution behavior remains unchanged. The statement waits for a lock until the statement or transaction times out. OceanBase Database V4.2.0 and later provide higher compatibility with LOCK TABLE syntaxes and enhances the features that are unavailable in earlier versions. Specifically, you can lock multiple tables, partitions, and subpartitions, and make the WAIT N and NOWAIT keywords take effect. For more information, see LOCK TABLE.

Multi-model support

Support for Oracle XML: XML is a standard self-explanatory text-based data exchange format. XML is widely needed in configuration description and data exchange scenarios. OceanBase Database V4.2.0 supports the following features of XML:

  • XMLType: You can define data of the XML type and manipulate XML data by using PL or SQL statements.
  • Basic functions: OceanBase Database V4.2.0 supports constructor functions such as XMLParse, XMLElement, XMLAttribute, XMLContent, and XMLAgg, and XPath-based query functions such as Extract and ExtractXML. You can call the XMLUpdate function to make incremental modifications on XML documents, such as modifying the data of an XML node. You can call the XMLSERIALIZE function to convert the XML data stored in a database into standard XML text.
  • Storage: OceanBase Database V4.2.0 supports the native XML binary storage format, which is a query-friendly storage format. Compared with text-based storage, this format can avoid parsing XML documents and accelerate XML queries.
  • Indexes: OceanBase Database V4.2.0 supports the creation of indexes in XML documents based on virtual generated columns.

For more information, see XMLType overview.

Performance improvements

Statistics functionality enhancement

Starting from OceanBase Database V4.0.0, statistics collection is fully initiated and maintained by the SQL layer, and statistics are no longer collected during major compaction. However, due to the incomplete functionality of statistics collection, there are some issues with performance and memory consumption during collection, which further affects the generation of the SQL plan. Additionally, the lack of effective monitoring methods for statistics collection makes it difficult for users to determine the status and expiration of statistics collection on various data tables, resulting in operational difficulties.

V4.2.0 enhanced the stability and usability of statistics collection. Online statistics collection optimizes the data structure and collection performance, improving performance by around 10% for the INSERT INTO SELECT and LOAD DATA methods. Offline statistics collection optimizes the plan generation path and memory usage, improving performance by 10%-20% in the scenario where 64 concurrent offline statistics collection tasks are being performed on the partitioned table tpcds_100g.

In addition, V4.2.0 now supports statistics collection monitoring and diagnostics, with the addition of the dynamic performance view [G]V$OB_OPT_STAT_GATHER_MONITOR for querying the real-time status of statistics collection tasks, the dictionary view DBA_OB_TASK_OPT_STAT_GATHER_HISTORY for querying the execution status of history statistics collection tasks, and the dictionary view DBA_OB_TABLE_OPT_STAT_GATHER_HISTORY for querying the execution status of history collection tasks on tables.

Dynamic sampling

When executing SQL queries, the optimizer in OceanBase Database needs to collect statistical information on tables and indexes in order to choose the optimal execution plan. If the statistical information is inaccurate or incomplete, the chosen execution plan may not be optimal, leading to a decrease in query performance. Basic statistical information is usually obtained through automatic or manual collection. However, if the data distribution changes, statistical information is not collected, or complex SQL queries are encountered, existing statistical information may no longer be accurate.

OceanBase Database V4.2.0 introduced the dynamic sampling feature, which samples database objects in advance during the plan generation phase, estimates the number of rows through sampling, and generates better execution plans for the cost model. Currently, you can control the dynamic sampling feature through system variables, query hints, and system parameters and the sampling set size is limited by the degree of parallelism. For more information, see Perform dynamic sampling by using optimizer.

Runtime Filter

Since V3.1.0, OceanBase Database has supported Join Bloom Filter to quickly filter data during data scanning in Join operations. In V4.0.0, Partition Bloom Filter was introduced to dynamically filter partitions for scenarios where Join keys are partition columns or partition column prefixes. Furthermore, in V4.1.0, multiple Bloom Filters can be generated within adjacent data flow operators (DFOs) and within a single DFO. Filters that dynamically filter data during execution, such as In, Range, and Bloom Filter, are collectively referred to as Runtime Filter (RF). V4.2.0 provides full support for Runtime Filter, improving the AP processing performance. You can manually enable Runtime Filter by using px_join_filter or px_part_join_filter, and disable it by using no_px_join_filter or no_px_part_join_filter. Additionally, four system variables are provided to adjust the execution strategy of Runtime Filter if necessary. For more information, see Runtime Filter.

Performance optimization under 4C

OceanBase Database V4.2.0 improved Sysbench performance under 4C16G (4 CPU cores and 16 GB of memory) scenarios by over 20% with a series of optimizations. These optimizations include auto-increment ID optimization, New Sort adaptive optimization, Callback Allocator optimization in PDML scenarios, time function call optimization, optimization of obtaining snapshots of single log stream statements, optimization of obtaining snapshots at tenant level, and optimization of enable_trace_log and enable_sql_audit.

Fast generation of random data

Table functions can return a data table as a result. Based on this, V4.2.0 introduced the Table Generator feature, which includes the built-in function generator(N). This function can be called in a Table function as table(generator(N)). In addition, new random functions such as RANDOM([N]) and RANDSTR(N, gen) and distribution control functions such as NORMAL(<mean> , <stddev> , <gen>), UNIFORM(<min> , <max> , <gen>), andZIPF(<s> , <N> , <gen>) are added and can be used with Table Generator to generate data. Compared with Oracle Connect By and MySQL Recursive CTE, OceanBase Table Generator has significant performance advantages. For more information, see GENERATOR.

OLAP capabilities

Read-only external tables

Tables in a database are stored in the database's storage space, while data of external tables is stored in an external storage service. External tables can be queried like regular tables, but are limited to read operations and do not support data manipulation language (DML) operations. Typically, when processing external data, data must be loaded or inserted into the database by using ETL tools. During this process, the database consumes resources such as storage space, disk I/O, and CPU. In contrast, external tables can directly read external data sources for query analysis without loading or inserting them into the database. For more information about the usage method and limitations, see Create external tables.

Scalability enhancement

Transfer and load balancing

OceanBase Database V4.0.0 underwent an architecture upgrade by introducing the concept of adaptive log streams to achieve an integrated architecture for standalone and distributed modes. This architecture provides more flexible scalability and supports dynamic transformation between standalone and distributed modes. However, the scalability was not fully improved in the released version V4.1.0, as the partitions and log streams were statically bound and therefore partition distribution could not be dynamically adjusted. This restricted the capabilities of automatic load balancing and deployment flexibility.

OceanBase Database V4.2.0 is the first version to fully implement the integrated architecture for standalone and distributed modes. It uses the transfer technology to split and merge log streams, supporting data migration across nodes on a per-partition basis. This truly achieved dynamic transformation between standalone and distributed modes, further improving the scalability.

The load balancing feature at the tenant level is mainly reflected in the following two aspects:

  • Tenant-level horizontal scaling: Users can extend their read-write service capabilities within and across zones by dynamically adjusting the Unit Number (the number of units that provide services in each zone) and Primary Zone (the list of zones that provide read-write services). The load balancing module will adaptively adjust the distribution of log streams and partitions based on the configured service capabilities.
  • Partition balancing: Partition distribution can be dynamically adjusted to achieve balance in the number of partitions and storage space on service nodes, even in the case of dynamic changes in tables and partitions.

For more information, see Load balancing.

Replicated tables

Replicated tables are a special type of table in OceanBase Database that can read the latest modifications from any "healthy" replica. For users with low write frequency and those that are more concerned about read operation latency and load balancing, replicated tables are a good choice. Replicated tables can sacrifice a small part of transaction commit performance while reading the latest data on any "healthy" follower. Here, "healthy" means that the follower has a smooth network connection and minimal replay progress gap with the leader.

In OceanBase Database V3.2.0, the replicated table feature was already supported, allowing a backup replica to be created on every server specified for a given tenant, and the main replica and all backup data are kept in strong synchronization using a fully synchronous policy. V4.2.0 further improved the replicated table feature, enhancing the ability to switch leaders without killing transactions. That is, when a user or load balancing initiates a leader switch, the execution can continue after the switch without killing transactions. Additionally, the new version of replicated tables has better write transaction performance, stronger disaster recovery capability for replicated tables, and lower impact on read operations when a replica fails. For more information, see Create a table.

High availability enhancement

Physical standby database

OceanBase Database V4.1.0 introduced a primary/standby solution based on third-party media archiving. This solution meets the basic requirements of primary and standby databases and is flexible in configuration, for example, not requiring network connectivity between primary and standby tenants. However, compared with the direct connectivity method, this approach has some disadvantages, such as increased storage and network costs, decreased performance and stability, increased maintenance difficulty, and usage limitations such as requiring the archiving to enabled for the standby database before a switchover.

Considering these factors, V4.2.0 enhanced physical standby databases with direct network connectivity, which shortened the log synchronization link between primary and standby databases and is more suitable for standalone and small to medium-sized users. Additionally, considering limitations in available bandwidth and potential instabilities in communication between standby databases, V4.2.0 also supports bandwidth throttling for standby databases. This helps avoid situations where excessive traffic from some standby databases affects the performance of other nodes when network bandwidth is limited. For more information about how to use the physical standby database, see Overview of physical standby database.

Resource utilization optimization

On-demand disk file expansion

OceanBase Database uses a strategy of pre-allocating disk space, which ensures that the database occupies a continuous block of disk space, avoiding resource shortages caused by other applications preempting the disk. Additionally, OceanBase Database allows customization of the file system based on this strategy to improve data access efficiency. However, in the case of a small amount of user data, there may be wasted disk space. V4.2.0 provides a new user configuration option for progressive disk expansion, which pre-allocates a reasonable disk size and automatically expands it based on the actual usage of the disk. For more information, see Configure dynamic expansion of disk data files.

Usability enhancement

Auto DOP

Parallel execution is a key capability for optimizing large data queries, and the optimizer generally uses DOP to describe the amount of parallel resources available. In previous versions, users had to determine whether to enable parallelism and adjust the DOP size with the consideration of execution conditions, response time requirements, and system resources. If needed, they had to modify the system variables and HINT based on their experience. V4.2.0 introduced the auto DOP feature while retaining the ability to manually adjust the DOP. This feature evaluates the time required to execute the query when generating a query plan, automatically determines whether to enable parallel execution, and determines the optimal DOP for the current query. The DOP selection policy can be controlled through the system variable parallel_degree_policy. For more information, see Auto DOP.

End-to-end diagnostics enhancement

OceanBase Database V4.2.0 significantly improved its diagnostic capabilities, including the first implementation of visual end-to-end tracing for SQL requests. This feature helps users quickly locate and trace specific problems during a particular execution phase, and identify the server and module in which the issue occurred with the aid of detailed execution information. It also provides Show Trace capabilities based on transactions and SQL queries. For business departments, they are often more concerned about the overall time consumption of a business service. For example, in an OLTP system, a business service is typically composed of one or more transactions. Therefore, tracing at the transaction level aligns better with the user's actual business scenario.

Each transaction forms a trace, recording the relevant execution information of each SQL request in the entire internal process of OBClient > ODP > OBServer. Users can quickly identify which statements were executed in a transaction and view their execution details from the client's perspective. Show Trace also provides convenient business system association capabilities for users. Users can set the app trace id corresponding to the calling request on the business database connection through the JDBC interface or SQL interface. This app trace id will be recorded in the end-to-end tracing information and displayed in Show Trace. When users find errors in a request or service database call associated with a certain app trace id, they can use this app trace id to quickly search for the corresponding database trace associated with the app trace id in the end-to-end diagnostic system, and then directly view the time consumption and error points of the request in each phase of the database link to quickly determine the component that triggered the issue. For more information, see Show a trace.

Logical plan management

V4.2.0 enhanced logical plan management with the following features:

  • After a user obtains the plan information of a query through the EXPLAIN syntax, the user can query the history through DBMS_XPLAN.display before the current session is disconnected. Alternatively, the user can specify to save the information to a target table using the EXPLAIN INTO syntax.
  • Automatically saves the plans of all executed queries, including physical and logical plans, for subsequent troubleshooting. The database clears the saved query plans when the cluster is restarted.
  • Displays the baseline plan of SQL plan management (SPM) using DBMS_XPLAN.DISPLAY_SQL_PLAN_BASELINE.
  • Displays the plan information of executing queries using DBMS_XPLAN.DISPLAY_ACTIVE_SESSION_PLAN and SESSION_ID.

For more information, see DISPLAY_ACTIVE_SESSION_PLAN.

National standards

GB18030-2022 character set

GB18030-2022 character set was released on July 19, 2022, and formally implemented on August 1, 2023, becoming a mandatory standard for full-text execution in information systems. Compared with the GB18030-2005 standard, the new standard supports more rare Chinese characters and minority languages. OceanBase Database V4.2.0 supports the new GB18030_2022 character set, along with the corresponding sorting methods. The character set name is GB18030_2022 in MySQL mode and ZHS32GB18030_2022 in Oracle mode. For more information, see Character sets.

Product forms

Standalone architecture-based primary/standby solution

OceanBase Database V4.1.0 introduced the standalone architecture, allowing users to deploy OceanBase Database on a single server. In V4.2.0, this architecture is further expanded to include a primary/standby solution. This allows users to deploy OceanBase Database on two servers, with one acting as the primary database and the other as the standby database. For more information, see the Physical standby database section of this topic.

Read-only replicas (R replicas)

Read-only replicas do not participate in the consensus protocol voting and cannot become leaders. They only replay logs generated by the leader and generate corresponding data locally. In other words, read-only replicas can only provide read services but not write services.

OceanBase Database V4.2.0 introduced read-only replicas, which can be used by replicated tables. That is, with broadcast log streams, read-only replicas can be deployed on OBServer nodes that do not need to participate in the voting, while full-featured replicas are deployed on OBServer nodes that need to participate in the voting. The purpose of doing so is to ensure that, ideally, replicated tables can provide strong consistency reads on any OBServer node.

Here is a comparison between read-only replicas and full-featured replicas:

Replica type Participates in election voting? Participates in log voting? SSTable Has clog Has MemTable
Full-featured replica Yes Yes Yes Yes Yes
Read-only replica No No Yes Yes Yes

Performance test report

The tests aim at comparing the performance of OceanBase Database V4.2 and V4.1 in different scenarios.

Test environment specifications

Type Specification
CPU architecture x86_64
ECS type ecs.g7.8xlarge
Compute 32 cores
Memory 128 GB
Disk 300 GB system disk, 2*400 GB cloud disks
Operating system CentOS Linux release 7.9.2009 (Core)

Version for test

Product Version information
OBServer (V4.2) OBServer (OceanBase_CE 4.2.0.0)
REVISION: 1-b274f1768fb31f46c38e691b2883324b01605b4b
BUILD_TIME: Jul 19 2023 08:31:51
ODP (V4.2) ODP (OceanBase 4.2.0.0 3883.el7)
REVISION: 3883-local-b6e947efa65fec48be04f5fb78d70019651503cf
BUILD_TIME: Jul 20 2023 09:36:15
OBServer (V4.1) OBServer (OceanBase_CE 4.1.0.0)
REVISION: 100000172023031416-6d4641c7bcd0462f0bf3faed011803c087ea1705
BUILD_TIME: Mar 14 2023 16:53:58
ODP (V4.1) ODP (OceanBase 4.1.0.0 1)
REVISION: 5617-local-e6798c479feaab9f9a60b89f87e4df5e284250b6
BUILD_TIME: Mar 11 2023 21:42:11

Note

To improve user experience and usability, the following tests are based on a small number of basic commonly used parameter settings for tuning, without performing extensive large-scale tuning or point-to-point optimization.

OLTP test with Sysbench

Test plan

  1. Deploy an OceanBase cluster by using obd. Deploy ODP and Sysbench on two separate servers, which will act as stress servers to avoid resource contention. Note that ODP is deployed on a separate server with 64 CPU cores and 128 GB of memory (server type: ecs.c7.16xlarge).
  2. Configure the OceanBase cluster. Make sure that the cluster is in the 1-1-1 architecture, with three zones and each zone having one OBServer node. After the cluster is deployed successfully, create the tenant and user required for running the Sysbench test (The sys tenant is a built-in system tenant used for managing the cluster, therefore, do not use the sys tenant to run the test). In two separate tests, set the primary zone for the tenant to RANDOM and Zone1, respectively. RANDOM indicates that the leader of the newly created table partition is randomly assigned to one of the three servers, while Zone1 indicates that the leader for the newly created table partition is concentrated on one server in Zone1.
  3. Launch the Sysbench client and run the point_select, read_write, read_only, and write_only tests.
  4. Set --time to 60s for each round of test. The number of threads can be 32, 64, 128, 256, 512, or 1,024.
  5. Prepare the test data: 30 non-partitioned tables with 1 million rows of data (--tables=30, -table_size set to 1000000).

Tenant specifications

  • MAX_CPU = 26
  • MEMORY_SIZE = 70g

Parameter tuning

ALTER system SET enable_sql_audit=false;
ALTER system SET enable_perf_event=false;
ALTER system SET syslog_level='PERF';
ALTER system SET enable_record_trace_log=false;

Test results

  • Point select performance

    Threads V4.1 QPS [RANDOM] V4.1 95% Latency (ms) [RANDOM] V4.2 QPS [RANDOM] V4.2 95% Latency (ms) [RANDOM] V4.2 QPS [Zone1] V4.2 95% Latency (ms) [Zone1]
    32 135146.05 0.27 138746.60 0.26 137423.12 0.27
    64 252277.60 0.30 252231.37 0.29 246275.56 0.31
    128 431564.13 0.36 447755.19 0.34 377949.26 0.50
    256 686271.21 0.55 730315.66 0.48 461791.47 0.94
    512 937428.74 0.95 1009966.93 0.90 535462.87 1.67
    1024 985232.01 2.35 1012734.80 2.66 537828.40 3.89
  • Read-only performance

    Threads V4.1 QPS [RANDOM] V4.1 95% Latency (ms) [RANDOM] V4.2 QPS [RANDOM] V4.2 95% Latency (ms) [RANDOM] V4.2 QPS [Zone1] V4.2 95% Latency (ms) [Zone1]
    32 115232.45 4.74 121733.00 4.65 119054.75 4.74
    64 214733.98 5.18 221563.16 5.09 208659.70 5.37
    128 366616.03 6.09 392138.56 5.67 282377.72 8.43
    256 553922.27 8.74 577951.13 8.58 316931.91 23.10
    512 662368.79 15.83 763726.51 17.01 317668.32 42.61
    1024 653733.97 54.83 740835.95 38.94 315535.24 80.03
  • Write-only performance

    Threads V4.1 QPS [RANDOM] V4.1 95% Latency (ms) [RANDOM] V4.2 QPS [RANDOM] V4.2 95% Latency (ms) [RANDOM] V4.2 QPS [Zone1] V4.2 95% Latency (ms) [Zone1]
    32 36840.88 5.37 43984.28 7.17 60851.38 4.10
    64 62582.56 8.13 82554.92 6.55 110359.75 4.49
    128 107054.05 9.56 114874.89 10.09 167415.76 5.99
    256 155494.00 13.70 181982.10 12.52 209163.02 10.27
    512 242458.53 17.32 253635.91 19.29 238568.50 18.28
    1024 291343.40 31.94 292482.33 36.89 249176.87 37.56
  • Read/Write performance

    Threads V4.1 QPS [RANDOM] V4.1 95% Latency (ms) [RANDOM] V4.2 QPS [RANDOM] V4.2 95% Latency (ms) [RANDOM] V4.2 QPS [Zone1] V4.2 95% Latency (ms) [Zone1]
    32 66669.18 11.45 72554.47 11.87 92995.95 7.84
    64 124559.80 12.52 139369.33 11.65 162191.70 9.22
    128 209150.84 15.27 247061.25 12.30 219285.86 13.70
    256 309329.85 20.00 313660.08 23.95 246672.33 25.74
    512 395940.95 33.12 497734.89 25.74 270444.49 57.87
    1024 454400.54 64.47 547816.87 54.83 256076.76 121.08

TPC-C benchmark test with BenchmarkSQL

Test plan

  1. Deploy an OceanBase cluster by using obd. Deploy ODP and TPC-C on one server to avoid insufficient stress on the client.
  2. Configure the OceanBase cluster. Make sure that the cluster is in the 1-1-1 architecture, with three zones and each zone having one OBServer node. After the cluster is deployed successfully, create the tenant and user required for running the TPC-C benchmark test (The sys tenant is a built-in system tenant used for managing the cluster, therefore, do not use the sys tenant to run the test). In two separate tests, set the primary zone for the tenant to RANDOM and Zone1, respectively. RANDOM indicates that the leader of the newly created table partition is randomly assigned to one of the three servers, while Zone1 indicates that the leader for the newly created table partition is concentrated on one server in Zone1.

Tenant specifications

  • MAX_CPU = 26
  • MEMORY_SIZE = 70g

Parameter tuning

#obproxy
ALTER proxyconfig SET proxy_mem_limited='4G';
ALTER proxyconfig set enable_compression_protocol=false;

#sys
ALTER system SET enable_sql_audit=false;
ALTER system SET enable_perf_event=false;
ALTER system SET syslog_level='PERF';
ALTER system SET enable_record_trace_log=false;

Software versions

  • mysql-connector-java-5.1.47
  • BenchmarkSQL V5.0

Test configuration

  • warehouse = 1000
  • loadWorder = 40
  • terminals = 800
  • runMins = 5
  • newOrderWeight = 45
  • paymentWeight = 43
  • orderStatusWeight = 4
  • deliveryWeight = 4
  • stockLevelWeight = 4

Test results

Test type V4.1 RANDOM V4.2 RANDOM V4.2 Zone1
tpmC (NewOrders) 293350.85 289711.96 139886.99
tpmTOTAL 652025.02 644025.66 310953.51
Transaction Count 3260125 3221995 1555658

TPC-H benchmark test

Test plan

  1. Deploy an OceanBase cluster by using obd. Deploy TPC-H on a separate server as the stress machine. You do not need to deploy ODP, as you can directly connect to any server for testing.
  2. Configure the OceanBase cluster. Make sure that the cluster is in the 1-1-1 architecture, with three zones and each zone having one OBServer node. After the cluster is deployed successfully, create the tenant and user required for running the TPC-H test (The sys tenant is a built-in system tenant used for managing the cluster, therefore, do not use the sys tenant to run the test). Set the primary zone of the tenant to RANDOM. Perform data loading first, then execute the 22 SQL queries multiple times and calculate the average.
  3. Prepare 100 GB of test data.

Tenant specifications

  • MAX_CPU = 26
  • MEMORY_SIZE = 70g

Parameter tuning

#sys
ALTER system flush plan cache GLOBAL;
ALTER system SET enable_sql_audit=false;
ALTER system SET enable_perf_event=false;
ALTER system SET syslog_level='PERF';
ALTER system SET enable_record_trace_log=false;

# Test tenant
SET GLOBAL ob_sql_work_area_percentage = 80;
SET GLOBAL ob_query_timeout = 36000000000;
SET GLOBAL ob_trx_timeout = 36000000000;
SET GLOBAL max_allowed_packet = 67108864;
SET GLOBAL parallel_servers_target = 624;

Test results

Query V4.1 (s) V4.2 (s)
Q1 2.18 2.24
Q2 0.23 0.48
Q3 1.48 1.49
Q4 0.53 0.66
Q5 0.98 0.95
Q6 0.13 0.14
Q7 1.46 1.35
Q8 0.92 1.09
Q9 2.82 4.46
Q10 1.10 0.95
Q11 0.17 0.19
Q12 1.36 1.34
Q13 1.89 1.86
Q14 0.29 0.41
Q15 0.88 0.88
Q16 0.66 0.67
Q17 1.62 1.57
Q18 0.82 0.91
Q19 0.61 0.64
Q20 1.07 1.12
Q21 2.54 2.52
Q22 1.08 1.11
Total 24.82 27.03

Note

In OceanBase Database V4.2.0, an optimization path for Runtime Filter was introduced. However, the optimizer has not fully adjusted its filtering estimation for Runtime Filter. As a result, there may be estimation deviations in certain scenarios, which can lead to the selection of suboptimal execution plans and longer execution times. Improvements are expected to be implemented in V4.2.2.

TPC-DS benchmark test

Test plan

  1. Deploy an OceanBase cluster by using obd. Deploy TPC-DS on a separate server as the stress machine. You do not need to deploy ODP, as you can directly connect to any server for testing.
  2. Configure the OceanBase cluster. Make sure that the cluster is in the 1-1-1 architecture, with three zones and each zone having one OBServer node. After the cluster is deployed successfully, create the tenant and user required for running the TPC-DS test (The sys tenant is a built-in system tenant used for managing the cluster, therefore, do not use the sys tenant to run the test). Set the primary zone of the tenant to RANDOM. Perform data loading first, then execute the 99 SQL queries multiple times and calculate the average.
  3. Prepare 100 GB of test data.

Tenant specifications

  • MAX_CPU = 26
  • MEMORY_SIZE = 70g

Parameter tuning

#sys
ALTER system flush plan cache GLOBAL;
ALTER system SET enable_sql_audit=false;
ALTER system SET enable_perf_event=false;
ALTER system SET syslog_level='PERF';
ALTER system SET enable_record_trace_log=false;

# Test tenant
SET GLOBAL ob_sql_work_area_percentage = 80;
SET GLOBAL ob_query_timeout = 36000000000;
SET GLOBAL ob_trx_timeout = 36000000000;
SET GLOBAL max_allowed_packet = 67108864;
SET GLOBAL parallel_servers_target = 624;

Test results

Query V4.1 (s) V4.2 (s)
Q1 0.63 0.64
Q2 3.46 1.17
Q3 0.16 0.17
Q4 9.43 9.76
Q5 1.63 1.71
Q6 0.37 0.42
Q7 0.28 0.31
Q8 0.39 0.26
Q9 1.89 1.90
Q10 0.50 0.51
Q11 5.79 6.02
Q12 0.28 0.23
Q13 2.04 0.57
Q14 11.38 11.22
Q15 0.23 0.23
Q16 0.92 0.95
Q17 0.52 0.46
Q18 0.32 0.37
Q19 0.17 0.28
Q20 0.19 0.19
Q21 0.29 0.31
Q22 1.11 1.23
Q23 14.20 14.55
Q24 1.56 1.41
Q25 0.62 0.49
Q26 0.21 0.22
Q27 0.35 0.42
Q28 7.44 6.58
Q29 0.64 0.53
Q30 0.27 0.31
Q31 0.62 0.67
Q32 0.11 0.11
Q33 0.77 0.55
Q34 0.37 0.56
Q35 0.87 0.90
Q36 0.31 0.32
Q37 0.42 0.46
Q38 1.49 1.60
Q39 2.31 0.85
Q40 0.16 0.17
Q41 0.18 0.08
Q42 0.11 0.13
Q43 0.64 0.65
Q44 0.45 0.49
Q45 0.39 0.32
Q46 0.81 0.65
Q47 1.16 1.21
Q48 0.61 0.66
Q49 0.86 0.92
Q50 0.81 0.68
Q51 2.82 2.83
Q52 0.11 0.12
Q53 0.24 0.25
Q54 1.05 1.04
Q55 0.11 0.11
Q56 1.01 0.56
Q57 0.79 0.80
Q58 0.60 0.65
Q59 13.64 3.11
Q60 1.13 0.69
Q61 0.30 0.33
Q62 0.40 0.42
Q63 0.23 0.24
Q64 1.84 1.89
Q65 2.70 2.77
Q66 0.46 0.49
Q67 16.12 9.59
Q68 0.67 0.48
Q69 0.44 0.46
Q70 1.18 1.36
Q71 0.54 0.54
Q72 1.47 1.34
Q73 0.31 0.41
Q74 6.36 4.36
Q75 2.26 2.55
Q76 0.49 0.50
Q77 0.71 0.74
Q78 3.64 3.46
Q79 0.65 0.70
Q80 1.78 3.45
Q81 0.30 0.26
Q82 0.67 0.79
Q83 0.69 0.76
Q84 0.19 0.20
Q85 0.84 0.92
Q86 0.36 0.33
Q87 1.59 1.70
Q88 0.65 0.85
Q89 0.30 0.32
Q90 0.19 0.47
Q91 0.13 0.16
Q92 0.10 0.10
Q93 0.75 0.76
Q94 0.62 0.65
Q95 6.37 6.36
Q96 0.38 0.44
Q97 0.93 0.94
Q98 0.30 0.30
Q99 0.70 0.80
Total time 160.83 138.75

Compatibility changes

Product behavioral changes

Feature Version Description
Table group 4.2
  • Partitioning attributes on table groups are no longer supported. The partitioning method for tables within a table group is no longer restricted by partition attributes, and partition management operations related to table groups are also no longer supported.
  • The semantics of aggregation and dispersion of partitions within a table group are no longer the same. The SHARDING attribute is introduced for table groups in V4.2.0 to control the aggregation and dispersion of table data within table groups. The TableGroup SHARDING attribute has three values: NONE, PARTITION, and ADAPTIVE.
Cap parameters 4.2 The default unit for Cap parameters is MB, but it is often wrongly assumed by users to be bytes, leading to settings that are far beyond the limit. To avoid unexpected results caused by updates to parameters without specifying the unit, the value unit must now be specified when updating Cap parameters. Updates without specifying the unit will fail.

View changes

View Version Change type Description
CDB/DBA_OB_TABLEGROUPS 4.2 Modified The partition attribute field will no longer have any meaning and will be displayed as NULL.
CDB/DBA_OB_TABLEGROUP_PARTITIONS 4.2 Deprecated The view will be deprecated and will no longer display data.
CDB/DBA_OB_TABLEGROUP_SUBPARTITIONS 4.2 Deprecated The view will be deprecated and will no longer display data.
CDB/DBA_OB_BALANCE_JOBS 4.2 New Displays the load balancing jobs being executed under a tenant. Only one load balancing job (JOB) can run under a tenant at a time, and each job can generate multiple load balancing tasks (TASK).
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_BALANCE_JOB_HISTORY 4.2 New Displays the history of load balancing jobs in the tenant.
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_BALANCE_TASKS 4.2 New Displays the load balancing jobs being executed in the tenant. Multiple load balancing tasks can run at the same time, and these tasks (TASK) belong to the same load balancing job (JOB).
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_BALANCE_TASK_HISTORY 4.2 New Displays the history of load balancing tasks in the tenant.
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_TRANSFER_TASKS 4.2 New Displays the transfer tasks being executed in the tenant.
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_TRANSFER_TASK_HISTORY 4.2 New Displays the history of transfer tasks in the tenant.
CDB displays data of all the tenants, but only the system tenant can access it.
CDB/DBA_OB_TABLE_LOCATIONS 4.2 Modified Added columns DUPLICATE_SCOPE, OBJECT_ID, TABLEGROUP_NAME, TABLEGROUP_ID, and SHARDING. This allows you to better observe the load balancing status of the cluster or tenant.
DBA_OB_TENANTS 4.2 Modified Added columns UNIT_NUM and COMPATIBLE to display the number of units in the cluster or tenant.
[G]V$OB_THREAD 4.2 New Displays the status information of all threads, with each row representing a thread.
[G]V$OB_LOCKS 4.2 New Implements the proprietary lock view [G]V$OB_LOCKS of OceanBase Database based on the V$LOCK view of Oracle. OceanBase Database adds locks of the TR type to the Oracle V$LOCK view to describe "row locks" before a minor compaction occurs.
[G]V$OB_ARBITRATION_SERVICE_STATUS 4.2 New Displays the connection status between the OceanBase cluster and the arbitration service.
[G]V$OB_ARBITRATION_MEMBER_INFO 4.2 New Displays information about the arbitration members of the cluster.
[G]V$OB_OPT_STAT_GATHER_MONITOR 4.2 New Displays the real-time status of statistics collection tasks.
DBA_OB_TASK_OPT_STAT_GATHER_HISTORY 4.2 New Displays the execution status of historical collection tasks.
DBA_OB_TABLE_OPT_STAT_GATHER_HISTORY 4.2 New Displays the execution status of historical collection tasks for tables.
[G]V$OB_UNITS 4.2 Modified Added the ZONE_TYPE and REGION columns.
CDB/DBA_OB_DATA_DICTIONARY_IN_LOG 4.2 Modified Displays the range of the data dictionary in the system log streams for easy consumption by CDC.
[G]V$OB_LOCKS 4.2 New Displays the current user's status for holding or requesting locks on various tables.
CDB/DBA_OB_LOG_RESTORE_SOURCE 4.2 New Displays the log restore source of the physically restored tenant and standby tenant.
V$OB_LS_LOG_RESTORE_STATUS 4.2 New Displays the log restore status at the log stream level.
V$OB_TIMESTAMP_SERVICE 4.2 New Displays the GTS and STS values of the tenant's clock service, the information about the node where the clock service is located, and the clock source type.
[G]V$OB_PX_P2P_DATAHUB 4.2 New Displays information about parallel data transmission operations.
[G]V$SQL_JOIN_FILTER 4.2 New Displays execution information of join filters.
DBA_OB_TABLE_STAT_STALE_INFO 4.2 New Displays the number of DDL operations performed on each table since the last statistics collection operation, and whether the current statistics have expired.
CDB/DBA/ALL_OB_EXTERNAL_TABLE_FILES 4.2 New Displays the file list corresponding to all created external tables in the current tenant.
CDB/DBA_OB_ACCESS_POINT 4.2 New Displays the list of servers that the tenants can access.
DBA_DB_LINKS 4.2 New Displays all DBLinks created in the current tenant. This view is new for MySQL tenants.
[G]V$OB_SQL_PLAN 4.2 New Displays the plan information collected by running the EXPLAIN PLAN command.
[G]V$OB_LOG_STAT 4.2 Modified Added the ARBITRATION_MEMBER, DEGRADED_LIST, and LEARNER_LIST columns.

System variable changes

Variale Version Change type Description
runtime_filter_type 4.2 New A global and session-level system variable used to set the tenant-level Runtime Filter type, which includes BLOOM_FILTER, RANGE, and IN types. If the value is set to an empty string, the Runtime Filter feature is turned off.
runtime_filter_wait_time_ms 4.2 New A global and session-level system variable used to set the maximum wait time for Runtime Filter. Default value: 10 ms.
runtime_filter_max_in_num 4.2 New A global and session-level system variable used to set the maximum number of distinct values (NDV) in the Runtime IN Filter. Default value: 1024.
runtime_bloom_filter_max_size 4.2 New A global and session-level system variable used to set the maximum memory usage for Runtime Bloom Filter, in bytes. Default value: 2 1024 1024 * 1024 (2 GB).
optimizer_dynamic_sampling 4.2 New A global and session-level system variable that specifies the level of dynamic sampling. Valid values: 0 and 1. The value 0 indicates to disable dynamic sampling and 1 indicates to enable it. Default value: 1.
parallel_degree_policy 4.2 New A global and session-level system variable that specifies the strategy for SQL parallel execution. Default value: MANUAL, which specifies to use auto DOP.
parallel_degree_limit 4.2 New A global and session-level system variable used to limit the maximum DOP chosen by the optimizer when the auto DOP policy is used. Default value: 0, which specifies not to limit the DOP chosen by the optimizer.
parallel_min_scan_time_threshold 4.2 New A global and session-level system variable used to increase the DOP when the estimated execution time for a base table scan exceeds the value of parallel_min_scan_time_threshold, thereby initiating more parallel queries. Default value: 1000 ms.
secure_file_priv 4.2 Modified A global system variable that can now only be modified by SQL statements executed by clients connected to the database via a local Unix Socket. This change was made for security reasons.

Parameter changes

Parameter Version Change type Description
enable_rebalance 4.2 Modified Adjusted to be a tenant-level parameter. Controls inter-tenant balancing for the system tenant and intra-tenant balancing for regular tenants.
balancer_idle_time 4.2 Modified Adjusted to be a tenant-level parameter. Represents the interval between the disaster recovery thread and balancing thread for the system tenant, and the interval for the log stream balancing thread for regular tenants.
partition_balance_schedule_interval 4.2 New A tenant-level parameter that sets the partition balance scheduling interval.
log_disk_throttling_percentage 4.2 New A tenant-level parameter that represents the percentage of non-recoverable log disk space that triggers log write throttling. When the non-recoverable log disk space reaches log_disk_throttling_percentage/100, log write throttling is triggered. Log write throttling stops when the non-recoverable log disk space falls below log_disk_throttling_percentage/100. Setting this parameter to 100 disables log write throttling. Default value: 60.
log_disk_throttling_maximum_duration 4.2 New A tenant-level parameter that represents the maximum expected available time for log disk space after log write throttling is triggered. The remaining available log disk space is expected to be consumed after log_disk_throttling_maximum_duration. A larger value extends the duration of log throttling and increases its intensity. Default value: 2 h.
_optimizer_ads_time_limit 4.2 New A hidden tenant-level parameter that controls the maximum sampling time (in seconds) for optimizer dynamic sampling. Default value: 10.
datafile_maxsize 4.2 New A cluster-level parameter that controls the upper limit for automatic disk data file expansion. Default value: 0.
datafile_next 4.2 New A cluster-level parameter that controls the step size for automatic disk data file expansion. Default value: 0.
_datafile_usage_upper_bound_percentage 4.2 New A cluster-level parameter that triggers automatic disk file expansion when the data file usage exceeds this value. Default value: 90.
standby_db_fetch_log_rpc_timeout 4.2 New A tenant-level parameter that sets the RPC timeout for fetching logs in the standby database, to control the detection of an unavailable server in the main database and switch to another server. Default value: 15s.
location_refresh_thread_count 4.2 Modified Changed the default value from 4 to 2.
enable_record_trace_id 4.2 Modified Changed the default value from True to False.
plan_cache_evict_interval 4.2 Modified Changed the default value from 1s to 5s.
devname 4.2 Modified Changed the effective mode of this parameter from dynamically taking effective to read-only.
local_ip 4.2 New A cluster-level parameter that represents the IP address of the installed OBServer node. This parameter is read-only.
observer_id 4.2 New A cluster-level parameter that is used by the RootService to assign a unique identifier to OBServer nodes in the cluster. This parameter is read-only.
standby_fetch_log_bandwidth_limit 4.2 New A cluster-level parameter that is used to set the maximum bandwidth occupied by all servers in the standby database when synchronizing logs from the primary database. The default value is 0, which specifies not to limit the bandwidth.
ls_gc_delay_time 4.2 New A tenant-level parameter that specifies the delay time for deleting log streams in the primary tenant in a physical standby scenario.
archive_lag_target 4.2 New A tenant-level parameter that specifies the delay time for log archiving in the tenant.
standby_db_preferred_upstream_log_region 4.2 New A tenant-level parameter that specifies the preferred region for synchronizing upstream logs in a physical standby scenario.
storage_meta_cache_priority 4.2 New A cluster-level parameter that specifies the priority of storing Meta Cache in kvcache.
range_optimizer_max_mem_size 4.2 New A tenant-level parameter that specifies the maximum memory usage of the Query Range module.
rootservice_memory_limit 4.2 Deprecated A cluster-level parameter that specifies the maximum memory capacity for Root Service.
trace_log_sampling_interval 4.2 Deprecated A cluster-level parameter that specifies the interval for periodically printing trace log information.
tenant_cpu_variation_per_server 4.2 Deprecated A cluster-level parameter that specifies the maximum allowed deviation in CPU quota between multiple units of a tenant.
token_reserved_percentage 4.2 Deprecated A cluster-level parameter that specifies a percentage of idle tokens reserved for the tenant.
global_write_halt_residual_memory 4.2 Deprecated A cluster-level parameter that specifies the threshold of remaining global memory that triggers the pause of write operations for regular tenants. The sys tenant is not affected.
plan_cache_high_watermark 4.2 Deprecated A cluster-level parameter that specifies the threshold of memory usage for the execution plan cache. When the memory usage exceeds the threshold, automatic eviction is triggered.
plan_cache_low_watermark 4.2 Deprecated A cluster-level parameter that specifies the threshold of memory usage for the execution plan cache. When the memory usage is less than the threshold, eviction is stopped.
max_px_worker_count 4.2 Deprecated A cluster-level parameter that specifies the maximum number of threads used by the SQL parallel query engine.
io_category_config 4.2 Deprecated A tenant-level parameter that specifies the percentage of I/O requests for each category.

Function/PL package changes

Function/PL package Version Change type Description
DBMS_SQL.LAST_ERROR_POSITION 4.2 New Returns the position where the syntax error occurs during the last call to DBMS_SQL.PARSE. This package applies to the Oracle mode.
DBMS_SESSION.RESET_PACKAGE 4.2 New Clears the status of all package variables in the current session. This package applies to the Oracle mode.
RANDOM([N]) 4.2 New Generates a random 64-digit integer. This function applies to both modes.
RANDSTR(N, gen) 4.2 New Generates a random string of N characters in length. gen indicates the random method. This function applies to both modes.
NORMAL(<mean> , <stddev> , <gen>) 4.2 New Returns a floating-point number that follows a normal distribution (also known as Gaussian distribution). This function applies to both modes.
UNIFORM(<min> , <max> , <gen>) 4.2 New Returns an integer or floating-point number that follows a uniform distribution. This function applies to both modes.
ZIPF(<s> , <N> , <gen>) 4.2 New Returns an integer that follows a Zipf distribution. This function applies to both modes.

Recommended versions of tools

The recommended platform tool versions for OceanBase Database V4.2.0 Beta are described in the following table:

Tool Version Remarks
ODP ODP V4.2.1 -
OCP OCP V4.1 OCP V4.1 is recommended for now. OCP V4.2.0 is expected be released in the middle of August 2023.
ODC ODC V4.1.3 BP3 ODC V4.1.3 BP3 is recommended for now. ODC V4.2.1 is expected be released at the end of August 2023.
OBCDC OBCDC V4.2.0 -
OMS OMS V4.1.0 OMS V4.1.0 is recommended for now. OMS V4.2.0 is expected be released in the middle of August 2023.
OceanBase C++ Call Interface (OCCI) OCCI V1.0.3 -
OceanBase Call Interface (OBCI) OBCI V2.0.7 -
OceanBase Embedded SQL in C (ECOB) ECOB V1.1.8 -
OBClient OBClient V2.2.3 -
LibOBClient LibOBClient V2.2.3 -
OBJDBC JDBC V2.4.4 -
ODBC ODBC V2.0.8 -

Upgrade notes

  • Online upgrade from OceanBase Database V4.1.0 to OceanBase Database V4.2.0_Beta is supported.
  • Online upgrade from OceanBase Database V3.x to OceanBase Database V4.2.0 is not supported.
  • OceanBase Database V3.x data can be migrated and upgraded to OceanBase Database V4.2.0 by using the logical migration feature of OMS.

Considerations

  • Enabling RPC SSL is not recommended in this version. Related issues will be optimized in future versions.
  • Upgrading from GB18030 to GB18030-2022 character set requires a logical upgrade.

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What is on this page
V4.2.0 BP1
Version information
Bug fixes
V4.2.0 Beta
Version information
Overview
Description of core features
Performance test report
Compatibility changes
Recommended versions of tools
Upgrade notes
Considerations