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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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QUICK START
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OceanBase Database

SQL - V3.2.4Enterprise Edition

  • Documentation Revision History
  • Document Overview
  • Get Started
    • What is OceanBase Database
      • Overview
      • Concepts
      • Compatibility with Oracle
        • Overview
        • SQL data types
        • Built-in functions
        • System views
      • Compatibility with MySQL
      • Management tools
      • Version rules
      • Limitations
    • Deploy OceanBase Database
      • Deployment introduction
      • Deployment process
      • Preparations
        • Prepare servers
        • Server configurations
        • Prepare installation packages
      • HA solution for OceanBase clusters
      • Deploy through the GUI
        • Configure the deployment environment
          • Deploy OAT
          • Verify deployment
          • Configure the clock source
          • Upload installation packages
          • Add a server
          • Initialize a server
        • Deploy OCP
          • Overview
          • Add an OCP configuration file
          • Deploy OCP
          • Verify deployment
        • Deploy the OceanBase cluster
          • (Optional) Configure DNS
          • Add an OBServer to the OCP resource pool
          • Create an OceanBase cluster
        • Deploy ODP
          • Overview
          • Deploy ODP
        • Create an OceanBase tenant
          • View resources available for a business tenant
          • Create a tenant
          • Verify deployment
        • Deploy OMS
          • Overview
          • Add an OMS configuration file
          • Deploy OMS
          • Verify deployment
        • Deploy ODC
          • Overview
          • Add an ODC configuration file
          • Deploy ODC
          • Verify deployment
      • Deploy through the CLI
        • Configure the deployment environment
          • Install oat-cli
          • Use oat-cli to configure the deployment environment
          • Configure the clock source
          • Upload installation packages
          • Configure host information
          • Check the environment before deployment
        • Deploy OCP
          • Overview
          • Generate a configuration file
          • Start deployment
          • Verify deployment
        • Deploy the OceanBase cluster
          • Deploy a single-replica OceanBase cluster
          • Deploy a three-replica OceanBase cluster
        • Deploy ODP
          • Deploy ODP by using the CLI
        • Create an OceanBase tenant
          • View resources available for a business tenant
          • Create a tenant
          • Verify deployment
        • Deploy OMS
          • Overview
          • Modify the configuration file
          • Start deployment
          • Verify deployment
        • Deploy ODC
          • Overview
          • Modify the configuration file
          • Start deployment
          • Verify deployment
    • Data migration
      • Overview
      • Migrate data by using OMS
        • Migrate data by using OMS
        • Migrate data from a MySQL database to a MySQL tenant of OceanBase Database by using OMS
        • Migrate data from a MySQL tenant of OceanBase Database to a MySQL database by using OMS
        • Migrate data from an Oracle database to a MySQL tenant of OceanBase Database by using OMS
        • Migrate data from an Oracle database to an Oracle tenant of OceanBase Database by using OMS
        • Migrate data from an Oracle tenant of OceanBase Database to an Oracle database by using OMS
        • Migrate data from a DB2 LUW database to a MySQL tenant of OceanBase Database by using OMS
        • Migrate data from a DB2 LUW database to an Oracle tenant of OceanBase Database by using OMS
        • Migrate data from a MySQL tenant of OceanBase Database to a DB2 LUW database by using OMS
        • Migrate data from an Oracle tenant of OceanBase Database to a DB2 LUW database by using OMS
        • Migrate data from a TiDB database to a MySQL tenant of OceanBase Database by using OMS
        • Migrate data between MySQL tenants of OceanBase Database by using OMS
        • Use OMS to migrate data between Oracle tenants of OceanBase Database
      • Migrate data by using OBLOADER & OBDUMPER
        • Import data by using OBLOADER
        • Export data by using OBDUMPER
      • Migrate data by using SQL scripts
      • Migrate data by using mysqldump
      • Migrate data by using DataX
      • Migrate data by using the OUTFILE statement
    • Database connections and routing
      • Overview
      • Manage ODP
        • ODP management 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 an ODP
        • ODP startup parameters
      • Database connections
        • Connect to OceanBase Database from OBClient
        • Connect to OceanBase Database from a MySQL client
        • Connect to OceanBase Database through ODC
      • Physical connections
      • Logical connections
        • Query all sessions
        • Query the details of a session
        • Query the metrics of a session
        • Query session variables
        • Terminate a session
      • Driver management
        • Overview
        • OB-ODBC
        • OBCI
        • OceanBase Connector/C
        • OceanBase Connector/J
      • Routing management
        • Table-based routing of ODP
        • SQL parser
        • LDC-based routing
        • ODP routing strategies
          • Read/Write splitting
          • Follower-first read
          • Blocklist mechanism
    • Cluster and multi-tenant management
      • Manage clusters
        • Create a cluster
        • Manage clusters
        • Manage cluster parameters
          • Overview
          • Query cluster-level parameters
          • Modify cluster-level parameters
        • Manage zones in a cluster
          • Overview of zone management
          • Add or delete a zone
          • Add or delete an encrypted zone
          • Start or stop a zone
          • Modify the configurations of a zone
          • Restart a zone
          • Isolate a failed zone
        • Manage OBServer nodes
          • Add an OBServer node
          • View OBServer node status
          • Stop or start an OBServer node
          • Restart an OBServer node
          • Isolate a failed OBServer node
          • Delete an OBServer node
          • Replace an OBServer node
        • View cluster information
        • Overview of cluster tenant management
        • Monitor cluster performance
        • Cluster performance report
        • View resource information of a cluster
      • Configuration management
        • Overview of configuration management
        • Set parameters
        • Set variables
        • Configure general parameters
        • Examples of parameter configuration in a production environment
        • Recommended minimum resource configuration
      • Resource management
        • Overview
        • Create a resource unit
        • Manage resource units
          • View configurations of a resource unit
          • Modify configurations of a resource unit
          • Drop a resource unit
        • Create a resource pool
        • Manage resource pools
          • Allocate a resource pool to a tenant
          • Modify a resource pool
          • Merge resource pools
          • Split a resource pool
          • Remove a resource pool from a tenant
          • Delete a resource pool
        • Query resource allocation
      • Tenant management
        • Overview of tenant management
        • Create a tenant
        • Copy a tenant
        • Manage tenants
          • Query tenant information
          • Modify a tenant
          • Rename a tenant
          • Drop a tenant
        • Manage users and privileges
          • Users and privileges
            • Overview
            • sys tenant
            • Oracle tenants
            • MySQL tenants
          • Oracle mode
            • Create a user
            • Set password complexity
            • Logon failure handling policies
            • View user privileges
            • Modify user privileges
            • Change the password of a user
            • Lock or unlock a user
            • Drop a user
            • Manage roles
              • Overview
              • Create a role
              • Assign a role to another role
              • Assign a role to a user
              • Specify valid or invalid roles for a user
              • View roles
              • Modify a role
              • Revoke a role
              • Drop a role
          • MySQL mode
            • Create a user
            • Set password complexity
            • Handle logon failures
            • View user privileges
            • Modify user privileges
            • Change the password of a user
            • Lock and unlock a user
            • Drop a user
        • Set and view the tenant allowlist
        • View the topology of a tenant
        • View the resource configurations of a tenant
        • Modify the resource configurations of a tenant
        • View the performance metrics of a tenant
        • View tenant sessions
        • Terminate a tenant session
        • Manage tenant parameters
          • Overview
          • Query tenant-level parameters
          • Modify tenant-level parameters
        • Manage tenant variables
      • Manage data storage
        • Minor compaction management
          • Overview
          • Automatically trigger a minor compaction
          • Manually initiate a minor compaction
          • View minor compaction information
          • Modify minor compaction settings
        • Major compaction management
          • Overview
          • Automatically trigger a major compaction
          • Configure scheduled major compactions
          • Manually initiate a major compaction
          • Manually control a major compaction
          • View major compaction information
            • View the major compaction process
            • View disk usage during a major compaction
          • Major compaction timeouts and errors
          • Modify major compaction settings
        • Data compression
          • Overview
          • Data encoding and compression
      • Manage memory
        • Overview
        • Memory structure
        • Set the maximum memory for an OceanBase database
        • Manage internal system memory
        • Manage internal tenant memory
        • Manage the memory of the plan cache
        • Query memory usage information
        • FAQ
      • Manage processes
        • Overview
        • Multi-tenant threads of OceanBase Database
        • FAQ about multi-tenant threads
        • Background threads of OceanBase Database
      • Manage logs
        • Log overview
        • Log generation levels
          • Log generation levels
          • Set a log generation level
        • Log file size and quantity management
          • Use the log file splitting feature
          • Control the number of log files
        • Query logs
          • Query the log of an SQL request
          • Query the log of a previous SQL request by using the SQL Trace feature
    • Database object management
      • Oracle mode
        • Manage tables
          • Overview
          • Create a table
          • Define column constraints
          • Query table definition
          • Modify a table
          • Empty a table
          • Drop a table
        • Manage table groups
          • Overview
          • Statements for table group management
        • Manage indexes
          • Overview
          • Create indexes
          • Query indexes
          • Drop an index
        • Manage views
        • Manage sequences
        • Manage synonyms
        • Manage triggers
          • Overview
          • Create a DML trigger
          • Create an INSTEAD OF trigger
          • Modify and drop a trigger
          • Disable or enable a trigger
          • Query trigger information
        • Manage directory objects
        • Manage DBLinks
      • MySQL mode
        • Manage databases
          • Create a database
          • View databases
          • Modify a database
          • Drop a database
        • Manage tables
          • Overview
          • Create a table
          • Define an auto-increment column
          • Define column constraints
          • Query table definition
          • Modify a table
          • Empty a table
          • Drop a table
        • Manage table groups
          • Overview
          • Statements for table group management
        • Manage indexes
          • Overview
          • Create indexes
          • Query indexes
          • Drop an index
        • Manage views
        • Manage sequences
        • Manage triggers
          • Overview
          • Create a DML trigger
          • Query trigger information
          • Drop a trigger
    • Distributed storage management
      • Overview of data distribution
      • Manage partitions
        • Oracle mode
          • Overview of partitions
          • Create a partitioned table
          • Manage a partitioned table
          • Create a subpartitioned table
          • Manage a subpartitioned table
          • Partition pruning
          • Query data in specified partitions
          • Create an index for a partitioned table
            • Overview of indexes
            • Local indexes
            • Global indexes
          • Create a partitioned table group
          • Add a partitioned table to a table group
          • Manage a partitioned table group
          • Create a subpartitioned table group
          • Add a subpartitioned table to a table group
          • Manage a subpartitioned table group
        • MySQL mode
          • Overview of partitions
          • Create a partitioned table
          • Manage a partitioned table
          • Create a subpartitioned table
          • Manage a subpartitioned table
          • Partition pruning
          • Query data in specified partitions
          • Create an index for a partitioned table
            • Overview of indexes
            • Local indexes
            • Global indexes
          • Create a partitioned table group
          • Add a partitioned table to a table group
          • Manage a partitioned table group
          • Create a subpartitioned table group
          • Add a subpartitioned table to a table group
          • Manage a subpartitioned table group
      • Manage replicas
        • Overview
        • Create a replica
        • Edit a tenant replica in a zone
        • Delete a tenant replica from a zone
      • Manage locality
        • Overview
        • Modify table locality
        • Modify tenant locality
      • Load balancing
        • Overview of load balancing
        • Manage automatic load balancing
        • Manually manage load balancing
          • Manually migrate and switch partition replicas
          • Set load balancing by using table groups
          • Set load balancing by primary zone
    • Performance tuning
      • Overview
      • Performance tools
        • System tools
          • General tool Top
          • CPU tools
          • Memory tools
          • Disk I/O tools
          • Network tools
        • Internal tables
          • gv$sysstat
          • gv$sql_audit
          • __all_virtual_trans_stat
        • Logs
          • slow trans
          • tenant dump
          • Slow queries
        • OCP
          • Monitoring and alerts
          • SQL diagnostics
          • Performance report
          • ASH report
          • Transaction diagnostics
          • Deadlock detection
      • 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
          • Route parameters on nodes
      • Business model tuning
        • Load balancing
        • SQL diagnostics
        • Distributed transactions
      • SQL tuning guide
        • Execution process of SQL queries
        • SQL execution plan
          • Introduction to SQL execution plans
          • Execution plan operators
            • TABLE SCAN
            • TABLE LOOKUP
            • 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
          • Plan cache
          • Fast parameterization
          • Real-time execution plan display
        • Distributed execution plan
          • Perform distributed execution and parallel queries
          • Generate a distributed plan
          • Schedule distributed execution plans
          • Manage distributed execution plans
          • Execute parallel queries
          • Perform parameter tuning for a parallel query
          • Parallel DML
        • SQL tuning
          • Overview
          • General procedure of SQL tuning
          • Monitor the SQL execution performance
            • gv$sql_audit
            • SQL Trace
            • Plan cache views
            • Examples of SQL performance analysis
              • 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 specified 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
              • Histograms
              • Manual statistics collection
              • Automatic statistics collection
            • Statistics management
              • Overview
              • Deletion
              • Setting
              • Import and export
              • Locking and unlocking
              • History management
              • Statistics preference management
            • Examples
          • 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 algorithms
              • Overview
              • Join algorithms
              • Join order
          • Manage execution plans
            • Optimizer hints
            • Plan binding
            • SQL plan management
        • Glossary
        • General issues in SQL tuning
      • Performance diagnostics
        • Monitor and diagnose the cluster performance
        • Tenant performance diagnostics
        • Monitor ODP performance
        • Monitor host performance
      • Case analysis
      • Performance test (MySQL mode)
        • Sysbench OLTP
        • BenchMarkSQL
        • TPC-H
      • Performance test (Oracle mode)
        • BenchMarkSQL
        • TPC-H
    • Data high availability
      • Flashback
        • Objects supported by the recycle bin
        • Recycle bin for databases, tables, and indexes
        • Recycle bin for tenants
        • Flash back objects from the recycle bin
        • Restore point
        • Use a flashback query to query data of multiple versions
      • Manage physical backup and restore
        • Introduction to physical backup and restore
        • Deploy NFS
        • Data backup for a cluster
          • Perform a backup by using commands
            • Preparations for backup
            • Initiate a log backup
            • Initiate a data backup
          • Perform a backup for a cluster in OCP
          • Backup of a specified path for a tenant
          • Enable backup for clusters based on log splitting
          • Check the backup progress
          • Stop a backup
          • Automatically clear backup data for clusters
          • Manually clear backup data for clusters
          • Stop backup data clearing for clusters
        • Back up data backups
          • Overview
          • Perform a secondary backup for a cluster by using commands
            • Preparations for secondary backup
            • Initiate a secondary log backup
            • Initiate a secondary data backup
          • Perform a secondary backup for clusters in OCP
          • Perform a secondary backup for tenants
          • View the progress of secondary data backup tasks
          • Stop a secondary backup
          • Automatically clear secondary backup data for clusters
          • Manually clear secondary backup data
          • Stop clearing secondary backup data
        • Update access_id and access_key for OSS in the backup destination during backup
        • Verify data
          • Overview
          • Verify backup data in a cluster
          • Verify backup data in a specified path in a cluster
          • Verify backup data in a specified path across clusters
          • View data verification results
        • Restore data
          • Preparations for restore
          • Perform full restore
          • Restore a specified table
          • Restore secondary backup data
          • View the restore progress and results
          • Cancel restore
        • Routine maintenance
          • Query backup parameters
          • Force stop all backup-related tasks
          • Set backup_zone
      • Primary/Standby cluster management
        • Overview
        • Considerations and limitations
        • Deploy the primary and standby clusters
          • Configuration requirements
          • Deploy a primary cluster
          • Check the configurations of the primary cluster
          • Deploy standby clusters in OCP
        • Tenant management
        • Log transfer service
          • Overview
          • Set the log transfer parameter for a standby cluster
          • Configure log compression
        • Protection mode
          • Overview
          • Protection modes and protection levels
          • Switch to another protection mode
        • Role switching
          • Preparations for a switchover
          • Perform a switchover in a command-line tool
          • Perform a switchover in OCP
          • Perform a failover in a command-line tool
            • Preparations for a failover
            • Perform a lossless failover
            • Connect the original primary cluster after a lossless failover
            • Connect other standby clusters after a lossless failover
            • Perform a lossy failover
            • Restore other clusters after a lossy failover
            • Correct the data after a failover
          • Perform a failover in OCP
        • Standby cluster read service
        • Delete a standby cluster
        • Standby cluster disconnection
          • Preparations for disconnection
          • Disconnect a standby cluster
        • Troubleshooting
          • Failover errors
          • Switchover errors
          • Protection mode switching errors
          • Tenant creation for a standby cluster got stuck
          • Data synchronization enablement errors
          • Standby cluster disconnection errors
    • Database security
      • Data storage encryption
        • Overview
        • MySQL mode
          • Enable storage encryption for a new table
          • Enable storage encryption for an existing table
          • Decrypt a table
        • Oracle mode
          • Enable storage encryption for a new table
          • Enable storage encryption for an existing table
          • Decrypt a table
      • Data transmission encryption
        • Overview
        • Transmission encryption of OBServer nodes
        • Transmission encryption of ODPs
      • RPC connection authentication
      • Set row-level access control
      • Audit databases
        • Overview
        • Enable audit
        • Audit user logon operations
        • Audit user operations
        • Audit specified database objects
    • O&M management
      • O&M overview
        • Overview
        • Monitoring
          • View status monitoring information
          • View performance monitoring information
          • Perform SQL diagnostics
        • Alerts
          • Alert configuration
          • Manage alert subscriptions
          • Perform alert management
          • Manage alert items
      • Database upgrade
        • Overview
        • Perform an upgrade
        • Perform a major compaction
        • Check upgrade results
      • Scale-in and scale-out
        • Overview
        • Cluster-level scale-in and scale-out
          • Scale-out
            • Add zones to a cluster
            • Add OBServer nodes to zones
          • Scale-in
            • Delete zones from a cluster
            • Delete OBServer nodes from zones
        • Scale-in and scale-out of tenant resources
          • Modify unit_config
          • Modify UNIT_NUM
      • Resource isolation
        • cgroup-based resource isolation
          • Enable cgroups-based CPU isolation between tenant worker threads
          • Clear cgroup configurations
      • Routine inspections
        • Overview
        • Check the cluster status
        • Check cluster parameters
        • Check the host status
        • Check tenant resource usage
        • Check cluster resource usage
        • Check the OBServer node status
        • Check the NTP offset
        • Check data backup
        • Check the ODP connection status
      • Troubleshooting
        • Overview
        • Issue analysis
          • View alerts
          • View logs
          • View error codes
          • Query views
        • Troubleshoot OBServer node restart failures
        • Troubleshoot unexpected exit of an observer process
        • Troubleshoot bootstrap failures
        • Troubleshoot database connection issues
        • Troubleshoot clock synchronization issues
        • Troubleshoot the absence of a leader
        • Troubleshoot replica migration issues
        • Troubleshoot exhausted tenant MemStore memory
        • Tenant memory overrun
        • Troubleshoot major compaction exceptions
        • Overloaded OBServer nodes
        • Troubleshoot row lock contention
        • Troubleshoot transaction errors
      • Emergency response
        • Overview
        • Analysis, diagnosis, and decision-making process
        • Common emergency response
          • Exceptions caused by hardware
            • Node failures
            • Network jitter
            • ODP faults
            • Other exceptions related to hardware and network
          • Exceptions caused by capacity changes
            • Exceptions of SQL queries
            • High disk I/O on an OBServer node
            • Overloaded NIC on an OBServer node
            • Full occupation of tenant memory
            • Full usage of ODP threads
            • Full usage of OBServer clog disk
            • Full usage of the OBServer data disk
            • Accumulated request queue of a tenant
          • Other cluster exceptions
            • Blocked tenant minor compaction
            • Blocked cluster major compaction
            • sys tenant or RootService exceptions
            • Insufficiency or leakage of system memory
            • Slow query of the queuing table
    • System references
      • System parameters
        • Overview
        • Summary of system parameters
        • Cluster-level parameters
          • all_cluster_list
          • auto_broadcast_location_cache_rate_limit
          • auto_delete_expired_backup
          • auto_leader_switch_interval
          • auto_refresh_location_cache_rate_limit
          • autoinc_cache_refresh_interval
          • backup_backup_archive_log_batch_count
          • backup_backup_archivelog_retry_interval
          • backup_backup_dest
          • backup_backupset_batch_count
          • backup_backup_dest_option
          • backup_backupset_retry_interval
          • 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_idle_time
          • 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_sync_time_warn_threshold
          • clog_transport_compress_all
          • clog_transport_compress_func
          • cluster
          • cluster_id
          • config_additional_dir
          • cpu_count
          • cpu_quota_concurrency
          • cpu_reserved
          • data_copy_concurrency
          • data_dir
          • data_disk_usage_limit_percentage
          • data_storage_error_tolerance_time
          • data_storage_warning_tolerance_time
          • datafile_disk_percentage
          • datafile_size
          • dead_socket_detection_timeout
          • debug_sync_timeout
          • default_compress
          • default_compress_func
          • default_row_format
          • default_transport_compress_func
          • devname
          • disk_io_thread_count
          • dtl_buffer_size
          • election_blacklist_interval
          • election_cpu_quota
          • enable_async_syslog
          • enable_auto_leader_switch
          • enable_auto_refresh_location_cache
          • enable_ddl
          • enable_election_group
          • enable_global_freeze_trigger
          • enable_log_archive
          • enable_major_freeze
          • enable_manual_merge
          • enable_merge_by_turn
          • enable_ob_ratelimit
          • enable_one_phase_commit
          • enable_perf_event
          • enable_pg
          • enable_rebalance
          • enable_record_trace_id
          • enable_record_trace_log
          • enable_rereplication
          • enable_rich_error_msg
          • enable_rootservice_standalone
          • enable_separate_sys_clog
          • enable_smooth_leader_switch
          • enable_sql_audit
          • enable_sql_operator_dump
          • enable_sys_unit_standalone
          • enable_syslog_recycle
          • enable_syslog_wf
          • enable_tcp_keepalive
          • enable_unit_balance_resource_weight
          • enable_upgrade_mode
          • fast_recovery_concurrency
          • flush_log_at_trx_commit
          • force_refresh_location_cache_interval
          • force_refresh_location_cache_threshold
          • freeze_trigger_percentage
          • fuse_row_cache_priority
          • gc_wait_archive
          • get_leader_candidate_rpc_timeout
          • 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_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
          • 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_archive_concurrency
          • log_restore_concurrency
          • major_compact_trigger
          • major_freeze_duty_time
          • 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_check_interval
          • 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_compact_trigger
          • 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_event_history_recycle_interval
          • ob_ratelimit_stat_period
          • obconfig_url
          • ofs_list
          • partition_table_check_interval
          • partition_table_scan_batch_count
          • plan_cache_evict_interval
          • plan_cache_high_watermark
          • plan_cache_low_watermark
          • px_task_size
          • px_workers_per_cpu_quota
          • 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_port
          • 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
          • server_temporary_offline_time
          • sql_audit_memory_limit
          • sql_audit_queue_size
          • ssl_client_authentication
          • ssl_external_kms_info
          • stack_size
          • switchover_process_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_io_bandwidth_limit
          • syslog_level
          • system_cpu_quota
          • system_memory
          • system_trace_level
          • tableapi_transport_compress_func
          • 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
          • 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
          • ob_esi_rpc_port
          • enable_ob_esi_process
          • ob_esi_session_timeout
          • ob_esi_io_concurrency
          • ob_esi_memory_limit
          • ob_esi_syslog_level
          • ob_esi_max_syslog_file_count
          • sql_login_thread_count
          • diag_syslog_per_error_limit
          • enable_cgroup
          • rpc_client_authentication_method
          • rpc_server_authentication_method
          • max_trx_part_size
        • Tenant-level parameters
          • audit_sys_operations
          • audit_trail
          • clog_max_unconfirmed_log_count
          • clog_persistence_compress_func
          • connection_control_failed_connections_threshold
          • connection_control_min_connection_delay
          • connection_control_max_connection_delay
          • default_progressive_merge_num
          • enable_clog_persistence_compress
          • enable_early_lock_release
          • enable_monotonic_weak_read
          • external_kms_info
          • enable_sql_extension
          • job_queue_processes
          • max_stale_time_for_weak_consistency
          • ob_enable_batched_multi_statement
          • ob_proxy_readonly_transaction_routing_policy
          • ob_ssl_invited_common_names
          • open_cursors
          • plsql_ccflags
          • plsql_code_type
          • plsql_debug
          • plsql_optimize_level
          • plsql_v2_compatibility
          • plsql_warnings
          • sql_work_area
          • tde_method
          • writing_throttling_maximum_duration
          • writing_throttling_trigger_percentage
          • workarea_size_policy
          • ob_query_switch_leader_retry_timeout
      • System variables (MySQL mode)
        • Overview
        • System variable summary
        • auto_increment_cache_size
        • auto_increment_increment
        • auto_increment_offset
        • autocommit
        • binlog_row_image
        • block_encryption_mode
        • character_set_client
        • character_set_connection
        • character_set_database
        • character_set_filesystem
        • character_set_results
        • character_set_server
        • character_set_system
        • collation_connection
        • collation_database
        • collation_server
        • connect_timeout
        • datadir
        • debug_sync
        • default_password_lifetime
        • div_precision_increment
        • error_on_overlap_time
        • explicit_defaults_for_timestamp
        • foreign_key_checks
        • group_concat_max_len
        • identity
        • init_connect
        • interactive_timeout
        • is_result_accurate
        • last_insert_id
        • license
        • lower_case_table_names
        • max_allowed_packet
        • max_sp_recursion_depth
        • max_user_connections
        • 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_language
        • 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_capability_flag
        • ob_compatibility_mode
        • ob_create_table_strict_mode
        • ob_default_replica_num
        • ob_early_lock_release
        • ob_enable_aggregation_pushdown
        • ob_enable_blk_nestedloop_join
        • ob_enable_hash_group_by
        • ob_enable_index_direct_select
        • ob_enable_jit
        • ob_enable_plan_cache
        • ob_enable_sql_audit
        • ob_enable_trace_log
        • ob_enable_transformation
        • ob_enable_transmission_checksum
        • ob_enable_truncate_flashback
        • ob_global_debug_sync
        • ob_last_schema_version
        • ob_log_level
        • ob_max_parallel_degree
        • ob_org_cluster_id
        • 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_proxy_partition_hit
        • ob_proxy_set_trx_executed
        • ob_query_timeout
        • ob_read_consistency
        • ob_reserved_meta_memory_percentage
        • ob_route_policy
        • ob_safe_weak_read_snapshot
        • ob_sql_audit_percentage
        • ob_sql_work_area_percentage
        • ob_stmt_parallel_degree
        • ob_tcp_invited_nodes
        • ob_temp_tablespace_size_percentage
        • ob_timestamp_service
        • ob_trace_info
        • ob_trx_idle_timeout
        • ob_trx_lock_timeout
        • ob_trx_timeout
        • optimizer_capture_sql_plan_baselines
        • optimizer_use_sql_plan_baselines
        • parallel_max_servers
        • parallel_servers_target
        • performance_schema
        • plugin_dir
        • query_cache_size
        • query_cache_type
        • read_only
        • recyclebin
        • resource_manager_plan
        • secure_file_priv
        • 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_warnings
        • system_time_zone
        • time_zone
        • timestamp
        • tracefile_identifier
        • transaction_isolation
        • transaction_read_only
        • tx_isolation
        • tx_read_only
        • undo_retention
        • version
        • version_comment
        • wait_timeout
        • 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
        • server_uuid
        • binlog_format
        • binlog_checksum
        • binlog_rows_query_log_events
        • log_bin
        • server_id
        • default_storage_engine
        • max_connections
        • event_scheduler
        • cte_max_recursion_depth
        • regexp_stack_limit
        • regexp_time_limit
      • System variables (Oracle mode)
        • Overview
        • System variable summary
        • auto_increment_cache_size
        • auto_increment_increment
        • auto_increment_offset
        • autocommit
        • binlog_row_image
        • block_encryption_mode
        • character_set_client
        • character_set_connection
        • character_set_database
        • character_set_filesystem
        • character_set_results
        • character_set_server
        • character_set_system
        • collation_connection
        • collation_database
        • collation_server
        • connect_timeout
        • datadir
        • debug_sync
        • default_password_lifetime
        • div_precision_increment
        • error_on_overlap_time
        • explicit_defaults_for_timestamp
        • foreign_key_checks
        • group_concat_max_len
        • identity
        • init_connect
        • interactive_timeout
        • is_result_accurate
        • last_insert_id
        • license
        • lower_case_table_names
        • max_allowed_packet
        • max_sp_recursion_depth
        • max_user_connections
        • 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_language
        • 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_capability_flag
        • ob_compatibility_mode
        • ob_create_table_strict_mode
        • ob_default_replica_num
        • ob_early_lock_release
        • ob_enable_aggregation_pushdown
        • ob_enable_blk_nestedloop_join
        • ob_enable_hash_group_by
        • ob_enable_index_direct_select
        • ob_enable_jit
        • ob_enable_plan_cache
        • ob_enable_sql_audit
        • ob_enable_trace_log
        • ob_enable_transformation
        • ob_enable_transmission_checksum
        • ob_enable_truncate_flashback
        • ob_global_debug_sync
        • ob_last_schema_version
        • ob_log_level
        • ob_max_parallel_degree
        • ob_org_cluster_id
        • 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_proxy_partition_hit
        • ob_proxy_set_trx_executed
        • ob_query_timeout
        • ob_read_consistency
        • ob_reserved_meta_memory_percentage
        • ob_route_policy
        • ob_safe_weak_read_snapshot
        • ob_sql_audit_percentage
        • ob_sql_work_area_percentage
        • ob_stmt_parallel_degree
        • ob_tcp_invited_nodes
        • ob_temp_tablespace_size_percentage
        • ob_timestamp_service
        • ob_trace_info
        • ob_trx_idle_timeout
        • ob_trx_lock_timeout
        • ob_trx_timeout
        • optimizer_capture_sql_plan_baselines
        • optimizer_use_sql_plan_baselines
        • parallel_max_servers
        • parallel_servers_target
        • performance_schema
        • plugin_dir
        • query_cache_size
        • query_cache_type
        • read_only
        • recyclebin
        • resource_manager_plan
        • secure_file_priv
        • sql_auto_is_null
        • sql_quote_show_create
        • sql_select_limit
        • sql_throttle_current_priority
        • sql_throttle_network
        • sql_throttle_priority
        • sql_throttle_rt
        • sql_warnings
        • system_time_zone
        • sql_safe_updates
        • time_zone
        • timestamp
        • tracefile_identifier
        • transaction_isolation
        • transaction_read_only
        • tx_isolation
        • tx_read_only
        • undo_retention
        • version
        • version_comment
        • wait_timeout
        • 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
        • event_scheduler
      • System views (MySQL mode)
        • Overview
        • Dictionary views
          • Overview
          • mysql.help_topic
          • mysql.help_category
          • mysql.help_keyword
          • mysql.help_relation
          • mysql.db
          • mysql.proc
          • mysql.time_zone
          • mysql.time_zone_name
          • mysql.time_zone_transition
          • mysql.time_zone_transition_type
          • mysql.user
          • information_schema.CHARACTER_SETS
          • information_schema.CHECK_CONSTRAINTS
          • information_schema.COLLATIONS
          • information_schema.COLLATION_CHARACTER_SET_APPLICABILITY
          • information_schema.COLUMNS
          • information_schema.DBA_OUTLINES
          • information_schema.ENGINES
          • information_schema.GLOBAL_STATUS
          • information_schema.GLOBAL_VARIABLES
          • information_schema.KEY_COLUMN_USAGE
          • information_schema.PARAMETERS
          • information_schema.PARTITIONS
          • information_schema.PROCESSLIST
          • information_schema.REFERENTIAL_CONSTRAINTS
          • information_schema.ROUTINES
          • information_schema.SCHEMATA
          • information_schema.SCHEMA_PRIVILEGES
          • information_schema.SESSION_STATUS
          • information_schema.SESSION_VARIABLES
          • information_schema.STATISTICS
          • information_schema.TABLES
          • information_schema.TABLE_CONSTRAINTS
          • information_schema.TABLE_PRIVILEGES
          • information_schema.USER_PRIVILEGES
          • information_schema.USER_RECYCLEBIN
          • information_schema.VIEWS
          • information_schema.CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
          • oceanbase.CDB_OB_BACKUP_ARCHIVELOG_SUMMARY
          • oceanbase.CDB_OB_BACKUP_JOB_DETAILS
          • oceanbase.CDB_OB_BACKUP_SET_DETAILS
          • oceanbase.CDB_OB_BACKUP_PROGRESS
          • oceanbase.CDB_OB_BACKUP_SET_EXPIRED
          • oceanbase.CDB_OB_BACKUP_ARCHIVELOG_PROGRESS
          • oceanbase.CDB_OB_BACKUP_CLEAN_HISTORY
          • oceanbase.CDB_OB_BACKUP_TASK_CLEAN_HISTORY
          • oceanbase.CDB_OB_RESTORE_PROGRESS
          • oceanbase.CDB_OB_RESTORE_HISTORY
          • oceanbase.CDB_CKPT_HISTORY
          • oceanbase.CDB_OB_BACKUP_VALIDATION_JOB
          • oceanbase.CDB_OB_BACKUP_VALIDATION_JOB_HISTORY
          • oceanbase.CDB_OB_TENANT_BACKUP_VALIDATION_TASK
          • oceanbase.CDB_OB_BACKUP_VALIDATION_TASK_HISTORY
          • oceanbase.CDB_OB_BACKUP_BACKUP_ARCHIVELOG_SUMMARY
          • oceanbase.CDB_OB_BACKUP_BACKUPSET_TASK_HISTORY
          • oceanbase.CDB_OB_BACKUP_BACKUPSET_TASK
          • oceanbase.CDB_OB_BACKUP_BACKUPSET_JOB_HISTORY
          • oceanbase.CDB_OB_BACKUP_BACKUPSET_JOB
          • oceanbase.CDB_OB_BACKUP_SET_OBSOLETE
          • oceanbase.CDB_OB_BACKUP_ARCHIVELOG
          • oceanbase.CDB_OB_BACKUP_BACKUP_ARCHIVELOG
          • oceanbase.CDB_OB_BACKUP_BACKUPPIECE_JOB
          • oceanbase.CDB_OB_BACKUP_BACKUPPIECE_JOB_HISTORY
          • oceanbase.CDB_OB_BACKUP_BACKUPPIECE_TASK
          • oceanbase.CDB_OB_BACKUP_BACKUPPIECE_TASK_HISTORY
          • oceanbase.CDB_OB_BACKUP_PIECE_FILES
          • oceanbase.CDB_OB_BACKUP_SET_FILES
          • information_schema.ST_GEOMETRY_COLUMNS
          • information_schema.ST_SPATIAL_REFERENCE_SYSTEMS
          • oceanbase.DBA_RSRC_PLANS
          • oceanbase.DBA_RSRC_PLAN_DIRECTIVES
          • oceanbase.DBA_RSRC_GROUP_MAPPINGS
          • oceanbase.DBA_RSRC_CONSUMER_GROUPS
        • Performance views
          • Overview
          • gv$plan_cache_stat
          • gv$plan_cache_plan_stat
          • gv$session_event
          • gv$session_wait
          • gv$session_wait_history
          • gv$system_event
          • gv$sesstat
          • gv$sysstat
          • gv$sql_audit
          • gv$latch
          • gv$memory
          • gv$memstore
          • gv$memstore_info
          • gv$plan_cache_plan_explain
          • gv$obrpc_outgoing
          • gv$obrpc_incoming
          • gv$sql
          • gv$sql_plan_monitor
          • gv$outline
          • gv$concurrent_limit_sql
          • gv$sql_plan_statistics
          • gv$server_memstore
          • gv$unit_load_balance_event_history
          • gv$tenant
          • gv$database
          • gv$table
          • gv$unit
          • gv$partition
          • gv$lock_wait_stat
          • gv$session_longops
          • gv$tenant_memstore_allocator_info
          • gv$minor_merge_info
          • gv$tenant_px_worker_stat
          • gv$partition_audit
          • gv$ps_stat
          • gv$ps_item_info
          • gv$sql_workarea
          • gv$sql_workarea_histogram
          • gv$ob_sql_workarea_memory_info
          • gv$server_schema_info
          • gv$merge_info
          • gv$lock
          • gv$sstable
          • gv$ob_trans_table_status
          • gv$tenant_memory_info
          • v$statname
          • v$event_name
          • v$session_event
          • v$session_wait
          • v$session_wait_history
          • v$sesstat
          • v$sysstat
          • v$system_event
          • v$memory
          • v$memstore
          • v$memstore_info
          • v$plan_cache_stat
          • v$plan_cache_plan_stat
          • v$plan_cache_plan_explain
          • v$sql_audit
          • v$obrpc_outgoing
          • v$obrpc_incoming
          • v$sql
          • v$sql_plan_monitor
          • v$sql_plan_statistics
          • v$unit
          • v$partition
          • v$lock_wait_stat
          • v$session_longops
          • v$latch
          • v$tenant_memstore_allocator_info
          • v$tenant_px_worker_stat
          • v$partition_audit
          • v$ob_cluster
          • v$ob_standby_status
          • v$ob_cluster_stats
          • v$ob_cluster_event_history
          • v$ps_stat
          • v$ps_item_info
          • v$sql_workarea
          • v$sql_workarea_active
          • v$sql_workarea_histogram
          • v$ob_sql_workarea_memory_info
          • v$ob_timestamp_service
          • v$server_schema_info
          • v$merge_info
          • v$lock
          • v$sql_monitor_statname
          • v$restore_point
          • v$ob_cluster_failover_info
          • v$encrypted_tables
          • v$encrypted_tablespaces
          • v$sstable
          • v$ob_trans_table_status
          • v$ob_all_clusters
          • v$tenant_memory_info
          • GV$OB_DTL_INTERM_RESULT_MONITOR
          • V$OB_DTL_INTERM_RESULT_MONITOR
          • V$RSRC_PLAN
      • System views (Oracle mode)
        • Overview
        • Dictionary views
          • Overview
          • ALL_ALL_TABLES
          • ALL_ARGUMENTS
          • ALL_COL_COMMENTS
          • ALL_COLL_TYPES
          • ALL_COL_PRIVS
          • ALL_CONSTRAINTS
          • ALL_CONS_COLUMNS
          • ALL_DEF_AUDIT_OPTS
          • ALL_DEPENDENCIES
          • ALL_DIRECTORIES
          • ALL_ERRORS
          • ALL_INDEXES
          • ALL_IND_COLUMNS
          • ALL_IND_EXPRESSIONS
          • ALL_IND_PARTITIONS
          • ALL_IND_SUBPARTITIONS
          • ALL_METHOD_PARAMS
          • ALL_OBJECTS
          • ALL_PART_COL_STATISTICS
          • ALL_PART_HISTOGRAMS
          • ALL_PART_INDEXES
          • ALL_PART_KEY_COLUMNS
          • ALL_PART_TABLES
          • ALL_PROCEDURES
          • ALL_PROFILES
          • ALL_SCHEDULER_JOB_ARGS
          • ALL_SCHEDULER_PROGRAM_ARGS
          • ALL_SEQUENCES
          • ALL_SOURCE
          • ALL_SUBPART_COL_STATISTICS
          • ALL_SUBPART_HISTOGRAMS
          • ALL_SUBPARTITION_TEMPLATES
          • ALL_SUBPART_KEY_COLUMNS
          • ALL_SYNONYMS
          • ALL_TABLES
          • ALL_TAB_COL_STATISTICS
          • ALL_TAB_COLS
          • ALL_TAB_COLUMNS
          • ALL_TAB_COMMENTS
          • ALL_TAB_HISTOGRAMS
          • ALL_TAB_PARTITIONS
          • ALL_TAB_PRIVS
          • ALL_TAB_STATISTICS
          • ALL_TAB_STATS_HISTORY
          • ALL_TAB_SUBPARTITIONS
          • ALL_TRIGGERS
          • ALL_TYPES
          • ALL_TYPE_ATTRS
          • ALL_TYPE_METHODS
          • ALL_USERS
          • ALL_VIEWS
          • AUDIT_ACTIONS
          • DBA_ALL_TABLES
          • DBA_ARGUMENTS
          • DBA_AUDIT_EXISTS
          • DBA_AUDIT_OBJECT
          • DBA_AUDIT_SESSION
          • DBA_AUDIT_STATEMENT
          • DBA_AUDIT_TRAIL
          • DBA_COLL_TYPES
          • DBA_COL_COMMENTS
          • DBA_COL_PRIVS
          • DBA_CONSTRAINTS
          • DBA_CONS_COLUMNS
          • DBA_ERRORS
          • DBA_INDEXES
          • DBA_IND_COLUMNS
          • DBA_IND_EXPRESSIONS
          • DBA_IND_PARTITIONS
          • DBA_IND_SUBPARTITIONS
          • DBA_METHOD_PARAMS
          • DBA_OBJECTS
          • DBA_OBJ_AUDIT_OPTS
          • DBA_PART_INDEXES
          • DBA_PART_KEY_COLUMNS
          • DBA_PART_TABLES
          • DBA_PROCEDURES
          • DBA_PROFILES
          • DBA_ROLES
          • DBA_ROLE_PRIVS
          • DBA_SCHEDULER_JOB_ARGS
          • DBA_SCHEDULER_JOBS
          • DBA_SCHEDULER_PROGRAM
          • DBA_SCHEDULER_PROGRAM_ARGS
          • DBA_SEGMENTS
          • DBA_SEQUENCES
          • DBA_SOURCE
          • DBA_STMT_AUDIT_OPTS
          • DBA_SUBPARTITION_TEMPLATES
          • DBA_SUBPART_KEY_COLUMNS
          • DBA_SYNONYMS
          • DBA_SYS_PRIVS
          • DBA_TABLES
          • DBA_TABLESPACES
          • DBA_TAB_COLS
          • DBA_TAB_COLUMNS
          • DBA_TAB_COMMENTS
          • DBA_TAB_PARTITIONS
          • DBA_TAB_PRIVS
          • DBA_TAB_STATS_HISTORY
          • DBA_TAB_SUBPARTITIONS
          • DBA_TRIGGERS
          • DBA_TYPES
          • DBA_TYPE_ATTRS
          • DBA_TYPE_METHODS
          • DBA_USERS
          • DBA_VIEWS
          • DBA_JOBS_RUNNING
          • DBA_JOBS
          • DBA_RECYCLEBIN
          • DBA_DEPENDENCIES
          • DBA_RSRC_CONSUMER_GROUPS
          • DBA_RSRC_GROUP_MAPPINGS
          • DBA_RSRC_PLANS
          • DBA_RSRC_PLAN_DIRECTIVES
          • DBA_DIRECTORIES
          • DBA_PART_COL_STATISTICS
          • DBA_PART_HISTOGRAMS
          • DBA_SUBPART_COL_STATISTICS
          • DBA_SUBPART_HISTOGRAMS
          • DBA_TAB_COL_STATISTICS
          • DBA_TAB_HISTOGRAMS
          • DBA_TAB_STATISTICS
          • DICT
          • DICTIONARY
          • NLS_DATABASE_PARAMETERS
          • NLS_INSTANCE_PARAMETERS
          • NLS_SESSION_PARAMETERS
          • ROLE_ROLE_PRIVS
          • ROLE_SYS_PRIVS
          • ROLE_TAB_PRIVS
          • STMT_AUDIT_OPTION_MAP
          • TENANT_VIRTUAL_GLOBAL_VARIABLE
          • TENANT_VIRTUAL_SESSION_VARIABLE
          • USER_ALL_TABLES
          • USER_ARGUMENTS
          • USER_AUDIT_OBJECT
          • USER_AUDIT_SESSION
          • USER_AUDIT_STATEMENT
          • USER_AUDIT_TRAIL
          • USER_COLL_TYPES
          • USER_COL_COMMENTS
          • USER_COL_PRIVS
          • USER_CONSTRAINTS
          • USER_CONS_COLUMNS
          • USER_ERRORS
          • USER_INDEXES
          • USER_IND_COLUMNS
          • USER_IND_EXPRESSIONS
          • USER_IND_PARTITIONS
          • USER_IND_SUBPARTITIONS
          • USER_OBJECTS
          • USER_PART_INDEXES
          • USER_PART_KEY_COLUMNS
          • USER_PART_TABLES
          • USER_PROCEDURES
          • USER_PROFILES
          • USER_ROLE_PRIVS
          • USER_SEGMENTS
          • USER_SEQUENCES
          • USER_SOURCE
          • USER_SUBPARTITION_TEMPLATES
          • USER_SUBPART_KEY_COLUMNS
          • USER_SYNONYMS
          • USER_SYS_PRIVS
          • USER_TAB_STATS_HISTORY
          • USER_TAB_SUBPARTITIONS
          • USER_TRIGGERS
          • USER_TABLES
          • USER_TABLESPACES
          • USER_TAB_COLS
          • USER_TAB_COLUMNS
          • USER_TAB_COMMENTS
          • USER_TAB_PARTITIONS
          • USER_TAB_PRIVS
          • USER_TYPES
          • USER_TYPE_ATTRS
          • USER_TYPE_METHODS
          • USER_JOBS
          • USER_VIEWS
          • USER_RECYCLEBIN
          • USER_DEPENDENCIES
          • USER_PART_COL_STATISTICS
          • USER_PART_HISTOGRAMS
          • USER_SUBPART_COL_STATISTICS
          • USER_SUBPART_HISTOGRAMS
          • USER_TAB_COL_STATISTICS
          • USER_TAB_HISTOGRAMS
          • USER_TAB_STATISTICS
          • DBA_CONTEXT
        • Performance views
          • Overview
          • GV$CONCURRENT_LIMIT_SQL
          • GV$DBLINK
          • GV$GLOBAL_TRANSACTION
          • GV$INSTANCE
          • GV$LOCK
          • GV$MEMORY
          • GV$MEMSTORE
          • GV$MEMSTORE_INFO
          • GV$OB_SQL_WORKAREA_MEMORY_INFO
          • GV$OPEN_CURSOR
          • GV$OUTLINE
          • GV$PLAN_CACHE_PLAN_EXPLAIN
          • GV$PLAN_CACHE_PLAN_STAT
          • GV$PLAN_CACHE_STAT
          • GV$PS_ITEM_INFO
          • GV$PS_STAT
          • GV$SERVER_MEMSTORE
          • GV$SESSION_WAIT
          • GV$SESSION_WAIT_HISTORY
          • GV$SESSTAT
          • GV$SQL_AUDIT
          • GV$SQL_WORKAREA
          • GV$SQL_WORKAREA_ACTIVE
          • GV$SQL_WORKAREA_HISTOGRAM
          • GV$SYSSTAT
          • GV$SYSTEM_EVENT
          • GV$SSTABLE
          • GV$TENANT_MEMORY_INFO
          • V$DBLINK
          • V$ENCRYPTED_TABLES
          • V$ENCRYPTED_TABLESPACES
          • V$GLOBAL_TRANSACTION
          • V$INSTANCE
          • V$LOCK
          • V$MEMORY
          • V$MEMSTORE
          • V$MEMSTORE_INFO
          • V$NLS_PARAMETERS
          • V$OB_SQL_WORKAREA_MEMORY_INFO
          • V$OPEN_CURSOR
          • V$PLAN_CACHE_PLAN_EXPLAIN
          • V$PLAN_CACHE_PLAN_STAT
          • V$PLAN_CACHE_STAT
          • V$PS_ITEM_INFO
          • V$PS_STAT
          • V$RESTORE_POINT
          • V$RSRC_PLAN
          • V$SESSION_WAIT
          • V$SESSION_WAIT_HISTORY
          • V$SESSTAT
          • V$SQL_AUDIT
          • V$SQL_MONITOR_STATNAME
          • V$SQL_WORKAREA
          • V$SQL_WORKAREA_ACTIVE
          • V$SQL_WORKAREA_HISTOGRAM
          • V$SSTABLE
          • V$SYSSTAT
          • V$SYSTEM_EVENT
          • V$TIMEZONE_NAMES
          • V$TENANT_MEMORY_INFO
          • V$VERSION
          • GV$OB_DTL_INTERM_RESULT_MONITOR
          • V$OB_DTL_INTERM_RESULT_MONITOR
          • V$GLOBALCONTEXT
      • 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 to 9499
        • 9500 to 9999
        • 22998, 30926, 38104, and 38105
      • Error codes (Oracle mode)
        • Overview
        • ORA-00000 to ORA-00999
        • ORA-01000 to ORA-01499
        • ORA-01500 to ORA-01999
        • ORA-02000 to ORA-04999
        • ORA-05000 to ORA-10000
        • ORA-10000 to ORA-19999
        • ORA-20000 to ORA-29999
        • ORA-30000 to ORA-49999
        • ORA-50000 to ORA-99999
        • PLS-00000 to PLS-00999
      • Reserved keywords (MySQL mode)
      • Reserved keywords (Oracle mode)
  • Develop
    • Developer guide (MySQL mode)
      • Connect to OceanBase Database
        • Overview
        • Connect to an OceanBase Database tenant by using a MySQL client
        • Connect to an OceanBase Database tenant by using OBClient
        • Connect to OceanBase Database by using ODC
      • Application development
        • Java
          • Java APIs
          • Connect Java applications to OceanBase Database
        • Python applications
        • Connect C applications to OceanBase Database
      • Create and manage database objects
        • About DDL statements
        • View the currently connected database
        • Change the password of a user
        • Data type
          • Common data types
          • Unsupported data types
        • Create database objects by using ODC
          • Create a table in ODC
          • Create a view in ODC
          • Create a function in ODC
          • Create a stored procedure in ODC
        • Create and manage tables
          • About tables
          • Create a table
          • About auto-increment columns
          • About types of column constraints
          • About table structure modification
          • About table clearing
          • About table dropping
          • Flash back a dropped table
          • About table privileges
        • Create and manage partition tables
          • About partitioned tables
          • Create a partitioned table
          • Manage a partitioned table
          • Create a subpartitioned table
          • Manage a subpartitioned table
          • Partition routing
          • Indexes on partitioned tables
          • Suggestions on using partitioned tables
        • Create and manage indexes
          • Overview
          • Create an index
          • Drop an index
        • Create and manage table groups
          • Overview
          • Create table groups
            • Create a non-partitioned table group
            • Create a subpartitioned table group
          • Specify a table group when creating a table
          • View information about a table group
          • Add a table to a table group
          • Drop a table group
        • Create and manage views
          • About views
          • Create a view
          • Modify a view
          • Drop a view
        • Create and manage sequences
          • About sequences
          • Create a sequence
          • Modify a sequence
          • Drop a sequence
        • Create and manage triggers
          • About triggers
          • Create a trigger
          • Drop a trigger
      • Query
        • Overview of queries
        • Run queries in ODC
        • Single-table queries
        • WHERE queries
        • ORDER BY queries
        • GROUP BY queries
        • Use the LIMIT clause in queries
        • Multi-table join queries
          • Multi-table join queries
          • INNER JOIN queries
          • OUTER JOIN queries
          • Subqueries
        • Use operators and functions in a query
          • Use arithmetic operators in queries
          • Use numerical functions in queries
          • Use string concatenation functions in queries
          • Use string functions in queries
          • Use date and time 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
          • Use the SELECT FOR UPDATE statement to lock query results
        • Execution plan
          • View an execution plan
          • Understand an execution plan
        • Use SQL hints in queries
        • Variables of query timeout
      • DML statements and transactions
        • DML statements
          • About DML statements
          • About the INSERT statement
          • UPDATE statements
          • About the DELETE statement
          • About the REPLACE INTO statement
        • Transactions
          • About transaction control statements
          • Start a transaction
          • Transaction savepoints
          • Commit a transaction
          • Roll back a transaction
          • About transaction timeout
    • Developer guide (Oracle mode)
      • Connect to OceanBase Database
        • Overview
        • Connect to an OceanBase Database tenant by using OBClient
        • Connect to OceanBase Database by using ODC
      • Application development
        • Java
          • OceanBase Connector/J
          • Java APIs
          • Connect Java applications to OceanBase Database
        • Python
          • OceanBase Connector/J in Python
          • Python APIs
          • Connect Python applications to OceanBase Database
        • C
          • OBCI
          • OBCI APIs
          • Connect C applications to OceanBase Database
      • Create and manage database objects
        • DDL statements
        • View the currently connected database
        • Change the password of a user
        • Create database objects by Using ODC
          • Create tables, views, functions, and stored procedures in ODC
          • Create a trigger in ODC
          • Create a sequence in ODC
          • Create a program package in ODC
          • Create a synonym in ODC
          • Create a type in ODC
        • Data type
          • Data types
          • Unsupported data types
        • Create and manage tables
          • Overview
          • Create a table
          • Define an auto-increment column by using the SEQUENCE keyword
          • Types of column constraints
          • Modify the structure of a table
          • Clear a table
          • Drop a table
          • Flash back a dropped table
          • Table privileges
        • Create and manage partition tables
          • Overview
          • Create a partitioned table
          • Manage a partitioned table
          • Create a subpartitioned table
          • Manage a subpartitioned table
          • Partition routing
          • Indexing on partitioned tables
          • Recommendations for using partitioned tables
        • Create and manage indexes
          • Drop an index
          • Overview
          • Create an index
        • Create and manage table groups
          • Overview
          • Create table groups
            • Create a non-partitioned table group
            • Create a subpartitioned table group
          • Specify a table group when creating a table
          • View information about a table group
          • Add a table to a table group
          • Drop a table group
        • Create and manage views
          • About views
          • Create a view
          • Modify a view
          • Drop a view
        • Create and manage sequences
          • Overview
          • Create a sequence
          • Modify a sequence
          • Drop a sequence
        • Create and manage synonyms
          • Overview
          • Create a synonym
          • Drop a synonym
        • Create and manage triggers
          • Overview
          • Create a trigger
          • Modify a trigger
          • Drop a trigger
          • Enable or disable a trigger
      • Query
        • About queries
        • Run queries in ODC
        • Single-table queries
        • Conditional queries
        • ORDER BY queries
        • GROUP BY queries
        • Use Row_Limiting_Clause in queries
        • Multi-table join queries
          • Multi-table join queries
          • INNER JOIN queries
          • OUTER JOIN queries
          • Subqueries
        • Use operators and functions in a query
          • Use arithmetic operators in queries
          • Use numerical functions in queries
          • Use string connectors 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
        • Execution plan
          • View execution plans of queries
          • Understand execution plans
        • Use SQL hints in queries
        • About query timeout variables
      • DML statements and transactions
        • DML statements
          • About DML statements
          • About the INSERT statement
          • About the UPDATE statement
          • About the MERGE statement
          • About the DELETE statement
        • Transactions
          • About transaction control statements
          • Start a transaction
          • Transaction savepoints
          • Commit a transaction
          • Roll back a transaction
          • About transaction timeout
    • Data migration
      • About data migration and synchronization
      • Migrate data by using OMS
      • Export and import data by using ODC
        • Overview
        • Export and import file formats
        • Batch export and import
        • Single table export and import
      • Migrate data by using SQL scripts
        • Common SQL scripts for data migration
        • Export data by using OUTFILE statements
        • Export data by using the LOAD DATA statement
      • Migrate data by using mysqldump
      • Migrate data by using OBLOADER & OBDUMPER
        • Import data by using OBLOADER
        • Export data by using OBDUMPER
      • Migrate data by using DataX
        • DataX
        • Examples of using DataX in OceanBase Database
    • Design conventions and constraints
      • Object naming conventions
        • Overview
        • Tenant naming conventions
        • User naming conventions
        • Table naming conventions
        • Field naming conventions
        • Other naming conventions
      • Object structure conventions
        • Field design
        • Table structure design
        • Partitioned table design
        • Index design
        • Other structural designs
      • Character set specifications
      • Database connection specifications
      • Best practices for database design
        • Configuration example (database connection pool)
          • Overview of database connection pool configuration
          • Example of configuring a Tomcat connection pool
          • Example of configuring a C3P0 connection pool
          • Example of configuring a Proxool connection pool
          • Example of configuring a HiKariCP connection pool
          • Example of configuring a DBCP connection pool
          • CommonPool configuration example
          • Example of configuring a JDBC connection pool
        • Development framework connection example
          • SpringBoot connection example
          • SpringBatch connection example
          • SpringJDBC connection example
          • SpringJPA connection example
          • Hibernate connection example
          • MyBatis connection example
        • Use of table comments
        • ORM conventions
        • Exception handling
    • SQL syntax
      • System tenant
        • Overview
        • ALTER SYSTEM
          • BACKUP
          • BALANCE TASK
          • BOOTSTRAP
          • CANCEL MIGRATE UNIT
          • CHANGE TENANT
          • CLUSTER
          • CONVERT
          • DELETE BACKUPSET
          • DELETE OBSOLETE BACKUP
          • FAILOVER
          • FLUSH PLAN CACHE
          • JOB
          • MERGE
          • MIGRATE UNIT
          • PARAMETER
          • REFRESH
          • REPLICA
          • RESTORE
          • ROOTSERVICE
          • SERVER
          • SET STANDBY CLUSTER
          • SWITCHOVER
          • THROTTLE
          • UPGRADE
          • VALIDATE
          • ZONE
        • ALTER RESOURCE POOL
        • ALTER RESOURCE UNIT
        • ALTER TENANT
        • CREATE RESOURCE POOL
        • CREATE RESOURCE UNIT
        • CREATE TENANT
        • DROP RESOURCE POOL
        • DROP RESOURCE UNIT
        • DROP TENANT
        • SET DECRYPTION
        • SET ENCRYPTION
      • User tenants (MySQL mode)
        • Elements
          • Data type
            • Overview
            • Numeric data types
              • Overview
              • Integer data types
              • Fixed-point data types
              • Floating-point data types
              • Bit value data type
            • Date and time data types
              • Overview
              • DATE, DATETIME, and TIMESTAMP types
              • TIME type
              • YEAR type
            • Character data types
              • Overview
              • CHAR and VARCHAR
              • BINARY and VARBINARY
            • BLOB and TEXT data types
              • Overview
              • BLOB types
              • TEXT types
            • ENUM data type
            • SET data type
            • JSON data types
              • Overview
              • Create a JSON value
              • Query and modify JSON values
              • Convert a JSON data type
            • Spatial data types
              • Overview
              • SRS
              • Create a spatial column
              • Create a spatial index
              • Spatial data formats
          • Expressions
            • Overview
            • Expression syntax
            • Convert data types in expression evaluation
          • Character sets and collations
            • Overview
            • Character sets
            • Collations
            • Database-level character sets and collations
            • Table-level character sets and collations
            • 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
          • Operator precedence
          • Arithmetic operators
          • Bitwise operators
          • Comparison operators
          • Logical operators
          • Assignment operators
          • Date and time operators
          • Concatenation operators
          • BINARY operator
          • CASE conditional operator
        • Sequence pseudocolumns
        • Functions
          • Overview
          • Single-row functions
            • Date and time 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
              • DAY
            • String functions
              • ASCII
              • BIN
              • BIT_LENGTH
              • CHAR
              • CHAR_LENGTH
              • CONCAT
              • CONCAT_WS
              • EXPORT_SET
              • ELT
              • FIELD
              • FIND_IN_SET
              • FORMAT
              • HEX
              • INSERT
              • INSTR
              • INT2IP
              • IP2INT
              • LCASE
              • LEFT
              • LENGTH
              • LOCATE
              • LOWER
              • LPAD
              • LTRIM
              • MAKE_SET
              • MID
              • OCT
              • ORD
              • POSITION
              • QUOTE
              • REGEXP
              • REGEXP_INSTR
              • REGEXP_LIKE
              • REGEXP_REPLACE
              • REGEXP_SUBSTR
              • REPEAT
              • REPLACE
              • REVERSE
              • RIGHT
              • RLIKE
              • RPAD
              • RTRIM
              • SPACE
              • STRCMP
              • SUBSTR
              • SUBSTRING
              • SUBSTRING_INDEX
              • TRIM
              • UCASE
              • UNHEX
              • UPPER
              • WEIGHT_STRING
              • TO_BASE64
              • FROM_BASE64
            • Conversion functions
              • CAST
              • CONVERT
            • Mathematical functions
              • ABS
              • ACOS
              • ASIN
              • ATAN
              • ATAN2
              • BIT_COUNT
              • CEIL
              • CEILING
              • CONV
              • COS
              • COT
              • CRC32
              • DEGREES
              • EXP
              • FLOOR
              • LN
              • LOG
              • LOG10
              • LOG2
              • MOD
              • NEG
              • PI
              • POW
              • POWER
              • RADIANS
              • RAND
              • ROUND
              • SIGN
              • SIN
              • SQRT
              • TAN
              • TRUNCATE
            • Comparison functions
              • GREATEST
              • INTERVAL
              • ISNULL
              • LEAST
            • Process control functions
              • 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
          • Analytic functions
            • APPROX_COUNT_DISTINCT
            • AVG
            • COUNT
            • CUME_DIST
            • DENSE_RANK
            • FIRST_VALUE
            • LAG
            • LAST_VALUE
            • LEAD
            • MAX
            • MIN
            • NTH_VALUE
            • NTILE
            • PERCENT_RANK
            • RANK
            • ROW_NUMBER
            • STD
            • STDDEV
            • STDDEV_POP
            • STDDEV_SAMP
            • SUM
            • VAR_POP
            • VAR_SAMP
            • VARIANCE
          • Encryption functions
            • AES_DECRYPT
            • AES_ENCRYPT
            • MD5
          • Information functions
            • BENCHMARK
            • CHARSET
            • COERCIBILITY
            • COLLATION
            • CONNECTION_ID
            • CURRENT_USER
            • DATABASE
            • FOUND_ROWS
            • LAST_INSERT_ID
            • SCHEMA
            • ROW_COUNT
            • SESSION_USER
            • SYSTEM_USER
            • USER
            • VERSION
            • OB_VERSION
          • JSON functions
            • Functions that create JSON values
              • JSON_ARRAY
              • JSON_OBJECT
              • JSON_QUOTE
            • Functions that search JSON values
              • JSON_CONTAINS
              • JSON_CONTAINS_PATH
              • JSON_EXTRACT
              • JSON_KEYS
              • JSON_OVERLAPS
              • JSON_SEARCH
              • JSON_VALUE
              • MEMBER OF
            • Functions that modify JSON values
              • JSON_ARRAY_APPEND
              • JSON_ARRAY_INSERT
              • JSON_INSERT
              • JSON_MERGE
              • JSON_MERGE_PATCH
              • JSON_MERGE_PRESERVE
              • JSON_REMOVE
              • JSON_REPLACE
              • JSON_SET
              • JSON_UNQUOTE
            • Functions that return JSON text attributes
              • JSON_DEPTH
              • JSON_LENGTH
              • JSON_TYPE
              • JSON_VALID
            • JSON utility functions
              • JSON_PRETTY
              • JSON_STORAGE_SIZE
            • JSON aggregate functions
              • JSON_ARRAYAGG
              • JSON_OBJECTAGG
          • Other functions
            • ANY_VALUE
            • COALESCE
            • DEFAULT
            • INET_ATON
            • INET_NTOA
            • INET6_ATON
            • INET6_NTOA
            • IS_IPV4
            • IS_IPV4_COMPAT
            • IS_IPV4_MAPPED
            • IS_IPV6
            • NVL
            • SLEEP
            • UUID
            • UUID_SHORT
            • VALUES
          • Spatial functions
            • Create a geometric function
            • Spatial operation functions
            • Spatial relation functions
            • Geometry property functions
            • Geometric format conversion functions
        • Queries and subqueries
          • Overview
          • Subqueries
          • JOIN
        • SQL statements
          • General syntax
          • CTE
          • ALTER DATABASE
          • ALTER OUTLINE
          • ALTER SEQUENCE
          • ALTER TABLE
          • ALTER TABLEGROUP
          • ALTER USER
          • ALTER VIEW
          • ANALYZE
          • CREATE DATABASE
          • CREATE INDEX
          • CREATE OUTLINE
          • CREATE RESTORE POINT
          • CREATE SEQUENCE
          • CREATE TABLE
          • CREATE TABLEGROUP
          • CREATE USER
          • CREATE VIEW
          • DEALLOCATE PREPARE
          • DELETE
          • DESCRIBE
          • DROP DATABASE
          • DROP INDEX
          • DROP OUTLINE
          • DROP RESTORE POINT
          • DROP TABLE
          • DROP TABLEGROUP
          • DROP SEQUENCE
          • DROP USER
          • DROP VIEW
          • EXECUTE
          • EXPLAIN
          • FLASHBACK
          • GRANT
          • HELP
          • INSERT
          • KILL
          • LOAD DATA
          • OPTIMIZE
          • PREPARE
          • PURGE
          • PURGE RECYCLEBIN
          • RENAME TABLE
          • RENAME USER
          • REPLACE
          • REVOKE
          • SAVEPOINT
          • SCHEMA
          • SELECT
            • SELECT
            • JOIN clause
            • OVER clause
            • UNION clause
          • SELECT INTO
          • SET
          • SET CHARSET
          • SET NAMES
          • SET PASSWORD
          • SET TRANSACTION
          • SHOW
          • TRANSACTION
          • TRUNCATE TABLE
          • UPDATE
          • USE
      • User tenants (Oracles mode)
        • SQL overview
        • Pseudocolumns
          • Overview
          • Hierarchical query pseudocolumns
          • Sequence pseudocolumns
          • ORA_ROWSCN pseudocolumn
          • ROWNUM pseudocolumn
          • ROWID pseudocolumn
        • Elements
          • Built-in data types
            • Overview of built-in data types
            • Character data types
              • Overview of character data types
              • 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
            • Date, time, and interval data types
              • Overview of datetime and interval data types
              • DATE data type
              • TIMESTAMP data type
              • TIMESTAMP WITH TIME ZONE date 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
            • Rowid data types
            • User-defined data types
          • Comparison rules of data types
            • 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 models
            • Overview
            • Number format models
            • Datetime format models
            • RR datetime format element
            • String-to-date conversion rules
          • Null values
            • Overview of nulls
            • Nulls in SQL functions
            • Nulls in comparison conditions
            • Nulls in conditional expressions
          • Comments
            • Overview
            • Comments within SQL statements
            • Comments on schema and nonschema objects
            • Hint
              • Overview of hints
              • Lists of hints
                • Hints related to access path
                • Hints related to join orders
                • Hints related to joins
                • Hints related to parallel execution
                • Hints related to query strategy
                • Hints related to query conversion
                • Other hints
          • Database objects
            • Schema objects
            • Non-schema objects
          • Database naming conventions
            • Overview
            • Database object names and qualifiers
            • Suggestions on schema object names
          • Methods of referencing database objects
            • Overview
            • Reference schema objects
            • Reference objects in a remote database
              • Create database links
              • Reference database links
            • Reference partition tables and indexes
            • Reference an attribute or method of an object type
        • Operators
          • Overview of operators
          • Operator precedence
          • Arithmetic operators
          • Concatenation operator
          • Hierarchical query operators
          • Set operators
          • COLLATE operator
        • Functions
          • Function overview
          • Single-row functions
            • Numeric functions
              • ABS
              • ACOS
              • ASIN
              • ATAN
              • ATAN2
              • BITAND
              • CEIL
              • COS
              • COSH
              • EXP
              • FLOOR
              • LN
              • LOG
              • MOD
              • NANVL
              • POWER
              • REMAINDER
              • ROUND
              • SIGN
              • SIN
              • SINH
              • SQRT
              • TAN
              • TANH
              • TRUNC
              • WIDTH_BUCKET
            • String functions that return strings
              • CHR
              • CONCAT
              • INITCAP
              • LOWER
              • LPAD
              • LTRIM
              • NLS_LOWER
              • 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
            • General comparison functions
              • GREATEST
              • LEAST
            • Conversion functions
              • ASCIISTR
              • CAST
              • CHARTOROWID
              • CONVERT
              • HEXTORAW
              • NUMTODSINTERVAL
              • NUMTOYMINTERVAL
              • RAWTOHEX
              • ROWIDTOCHAR
              • ROWIDTONCHAR
              • 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
            • XML functions
              • XMLAGG
              • XMLATTRIBUTES
              • XMLELEMENT
              • XMLPARSE
          • 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) Functions
            • ROLLUP
            • STDDEV
            • STDDEV_POP
            • STDDEV_SAMP
            • SUM
            • VAR_POP
            • VAR_SAMP
            • VARIANCE
            • WMSYS.WM_CONCAT/WM_CONCAT
          • Analytic functions
            • Analytic functions
            • 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) Functions
            • ROW_NUMBER
            • STDDEV
            • STDDEV_POP
            • STDDEV_SAMP
            • SUM
            • VAR_POP
            • VAR_SAMP
            • VARIANCE
            • WMSYS.WM_CONCAT/WM_CONCAT
        • 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 of SQL conditions
          • 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 of queries and subqueries
          • Simple query
          • Hierarchical query
          • Compound queries
          • Join queries
          • Subquery
          • DUAL table query
        • SQL statements
          • DDL
            • ALTER INDEX
            • ALTER KEYSTORE
            • ALTER OUTLINE
            • ALTER PROFILE
            • ALTER ROLE
            • ALTER SEQUENCE
            • ALTER SESSION
            • ALTER SYSTEM FLUSH PLAN CACHE
            • ALTER SYSTEM PARAMETER
            • ALTER TABLE
            • ALTER TABLEGROUP
            • ALTER USER
            • CREATE DIRECTORY
            • CREATE DATABASE LINK
            • CREATE INDEX
            • CREATE KEYSTORE
            • CREATE OUTLINE
            • CREATE PROFILE
            • CREATE RESTORE POINT
            • CREATE ROLE
            • CREATE SEQUENCE
            • CREATE SYNONYM
            • CREATE TABLE
            • CREATE TABLEGROUP
            • CREATE TABLESPACE
            • CREATE USER
            • CREATE VIEW
            • DROP DIRECTORY
            • DROP DATABASE LINK
            • DROP INDEX
            • DROP OUTLINE
            • DROP PROFILE
            • DROP RESTORE POINT
            • DROP ROLE
            • DROP SEQUENCE
            • DROP SYNONYM
            • DROP TABLE
            • DROP TABLEGROUP
            • DROP TABLESPACE
            • DROP USER
            • DROP VIEW
            • RENAME
            • TRUNCATE TABLE
          • DML
            • DELETE
            • INSERT
            • MERGE
            • PURGE
            • SELECT
              • SIMPLE SELECT
              • Set-based SELECT
              • WITH clause
            • UPDATE
          • DCL
            • ANALYZE
            • AUDIT
            • COMMENT
            • COMMIT
            • EXPLAIN
            • FLASHBACK TABLE BEFORE DROP
            • GRANT
            • KILL
            • REVOKE
            • ROLLBACK
            • SAVEPOINT
            • SET NAMES
            • SET PASSWORD
            • SET ROLE
            • SET VARIABLE
            • SHOW
            • SHRINK
            • TRANSACTION
    • PL reference
      • What is PL?
        • Overview
        • Main features of PL
        • PL architecture
      • PL reference (MySQL mode)
        • Syntax of PL stored programs
        • Stored programs
          • Overview
          • Variables in stored programs
          • Stored procedures
          • Stored functions
          • Triggers
          • Access control and account management
          • Limitations on stored programs
        • Cursors
          • Overview
          • Cursor execution process
          • Limitations on server cursors
        • Conditional control statements
          • CASE
          • IF
          • ITERATE
          • LEAVE
          • LOOP
          • REPEAT
          • RETURN
          • WHILE
        • Data manipulation statements
          • CALL
          • DO
        • Data definition statements
          • CREATE FUNCTION
          • CREATE PROCEDURE
          • CREATE TRIGGER
          • DROP FUNCTION
          • DROP PROCEDURE
          • DROP TRIGGER
        • Database management statements
          • SHOW CREATE FUNCTION
          • SHOW CREATE PROCEDURE
          • SHOW CREATE TRIGGER
          • SHOW FUNCTION STATUS
          • SHOW PROCEDURE STATUS
          • SHOW TRIGGERS
        • Dictionary view
          • INFORMATION_SCHEMA PARAMETERS
          • INFORMATION_SCHEMA ROUTINES
          • INFORMATION_SCHEMA TRIGGERS
        • Exception handling
          • Overview
          • DECLARE ... CONDITION
          • DECLARE ... HANDLER
          • GET DIAGNOSTICS
          • RESIGNAL
          • SIGNAL
          • Effective scope of an exception handler
          • Diagnostics area
          • Exception handling and OUT/INOUT parameters
          • Limitations on exception handling
        • PL packages
          • 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_STATS
            • Overview
            • DELETE_COLUMN_STATS
            • DELETE_TABLE_STATS
            • EXPORT_COLUMN_STATS
            • EXPORT_TABLE_STATS
            • FLUSH_DATABASE_MONITORING_INFO
            • GATHER_TABLE_STATS
            • IMPORT_COLUMN_STATS
            • IMPORT_TABLE_STATS
            • LOCK_PARTITION_STATS
            • LOCK_SCHEMA_STATS
            • LOCK_TABLE_STATS
            • SET_COLUMN_STATS
            • SET_TABLE_STATS
            • UNLOCK_PARTITION_STATS
            • UNLOCK_SCHEMA_STATS
            • UNLOCK_TABLE_STATS
        • Reserved and non-reserved PL keywords
      • PL reference (Oracle mode)
        • Language basics
          • Character sets
          • Lexical units
          • Declaration
          • Reference identifiers
          • Scope and visibility of identifiers
          • Assign values
          • Expressions
          • PL blocks
          • Subprograms
          • Error-reporting functions
        • Data types
          • Overview
          • SQL data types
          • LOB data types
          • BOOLEAN type
          • User-defined subtypes
          • PLS_INTEGER and BINARY_INTEGER
          • Arrays
        • Flow control
          • Overview
          • Conditional control
          • Loop control
          • Sequential control
        • Collections and records
          • Overview
          • Collections
          • Associative arrays
          • Varrays
          • Nested tables
          • Collection constructor function
          • Collection methods
            • Overview of collection methods
            • 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
        • Static SQL
          • Overview
          • Cursors
            • Overview
            • Cursor attributes
            • Implicit cursors
            • Explicit cursors
            • Cursor variables
            • Traverse cursor data by using the FOR loop
            • Modify and drop a cursor
          • Transaction processing and control
          • Autonomous transactions
            • Overview
            • Control autonomous transactions
            • Autonomous triggers
        • Dynamic SQL
          • Overview
          • Execute dynamic SQL statements
          • DBMS_SQL system package
        • Stored procedures and functions
          • Overview
          • Create a stored procedure
          • Create a function
          • Manage stored procedures and functions
          • Privilege control
          • User-defined aggregate functions
            • Overview
            • Interface for user-defined aggregate functions
            • Create user-defined aggregate functions
            • Use user-defined aggregate functions
        • Triggers
          • Overview
          • Create a DML trigger
          • Modify and drop a trigger
          • Disable or enable a trigger
          • Query trigger information
          • INSTEAD OF DML trigger
        • Packages
          • Overview
          • Create a program package
          • Overloaded programs in a package
          • Manage program packages
          • Definition of the PL environment by the STANDARD package
        • Exception handling
          • Overview
          • Compile-Time alerts
          • 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 packages
          • Overview
          • DBMS_APPLICATION_INFO
            • Overview
            • READ_CLIENT_INFO
            • READ_MODULE
            • SET_ACTION
            • SET_CLIENT_INFO
            • SET_MODULE
          • 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
            • COMPARE
            • COPY
            • CREATETEMPORARY
            • ERASE
            • FREETEMPORARY
            • GETLENGTH
            • ISOPEN
            • INSTR
            • OPEN
            • READ
            • SUBSTR
            • TRIM
            • WRITE
            • WRITEAPPEND
          • DBMS_LOCK
            • Overview
            • SLEEP
          • DBMS_METADATA
            • Overview
            • GET_DDL
          • DBMS_OUTPUT
            • Overview
            • DISABLE
            • ENABLE
            • GET_LINE
            • GET_LINES
            • NEW_LINE
            • PUT
            • PUT_LINE
          • DBMS_PLAN_CACHE
            • Overview
            • PURGE
          • 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_PROGRAM
            • DEFINE_PROGRAM_ARGUMENT
            • DISABLE
            • DROP_JOB
            • DROP_PROGRAM
            • ENABLE
            • GENERATE_JOB_NAME
            • RUN_JOB
            • SET_ATTRIBUTE
            • SET_JOB_ARGUMENT_VALUE
          • DBMS_SESSION
            • Overview
            • CLEAR_ALL_CONTEXT
            • CLEAR_CONTEXT
            • CLEAR_IDENTIFIER
            • SET_CONTEXT
            • SET_IDENTIFIER
          • DBMS_SQL
            • Overview
            • BIND_VARIABLE
            • CLOSE_CURSOR
            • COLUMN_VALUE
            • DEFINE_COLUMN
            • DEFINE_ARRAY
            • DESCRIBE_COLUMNS
            • EXECUTE
            • EXECUTE_AND_FETCH
            • FETCH_ROWS
            • IS_OPEN
            • OPEN_CURSOR
            • PARSE
          • DBMS_STATS
            • Overview
            • DELETE_COLUMN_STATS
            • DELETE_TABLE_STATS
            • EXPORT_COLUMN_STATS
            • EXPORT_TABLE_STATS
            • FLUSH_DATABASE_MONITORING_INFO
            • GATHER_TABLE_STATS
            • IMPORT_COLUMN_STATS
            • IMPORT_TABLE_STATS
            • LOCK_PARTITION_STATS
            • LOCK_SCHEMA_STATS
            • LOCK_TABLE_STATS
            • SET_COLUMN_STATS
            • SET_TABLE_STATS
            • UNLOCK_PARTITION_STATS
            • UNLOCK_SCHEMA_STATS
            • UNLOCK_TABLE_STATS
          • DBMS_UTILITY
            • Overview
            • ACTIVE_INSTANCES
            • COMMA_TO_TABLE
            • 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
          • 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
          • 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_FILE
            • Overview
            • FCLOSE
            • FFLUSH
            • FOPEN
            • FGETPOS
            • FREMOVE
            • FRENAME
            • FSEEK
            • NEW_LINE
            • GET_LINE
            • PUT
            • PUT_LINE
          • UTL_ENCODE
            • Overview
            • BASE64_DECODE
            • BASE64_ENCODE
          • UTL_I18N
            • Overview
            • RAW_TO_CHAR
            • STRING_TO_RAW
          • UTL_RAW
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OceanBase Database Enterprise Edition V3.2.4

Last Updated:2023-10-24 09:23:04  Updated
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What is on this page
V3.2.4 BP4
Version information
Enhanced features
Behavioral changes
Parameter changes
System variable changes
Bug fixes
V3.2.4 BP3
Version information
Enhanced features
Behavioral changes
Parameter changes
System variable changes
Considerations
Bug fixes
V3.2.4 BP2
Version information
Enhanced features
Considerations
Bug fixes
V3.2.4 BP1
Version information
Enhanced features
Compatibility changes
Bug fixes
Considerations
V3.2.4
Version information
Overview
New features
Compatibility changes
Upgrade notes
Recommended versions of tools
Considerations

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V3.2.4 BP4

Version information

  • Release date: June 21, 2023
  • Version: V3.2.4 BP4
  • RPM version: oceanbase-3.2.4.4-104000052023062021

Enhanced features

  • The OBKV feature is optimized. The COUNT function for a single partition is supported based on the table model. The definition of expired columns is supported to automatically delete expired data.
  • MySQL data types are optimized. Specifically, the NCHAR and NVARCHAR data types and the SELECT N'xxx' syntax are supported.
  • The compatibility with Oracle functions is improved. The SOUNDEX and NLS_INITCAP functions are supported. At present, the NLS_INITCAP function supports only NLS_SORT=BINARY.
  • Security is hardened. The _enable_reserved_user_dcl_restriction parameter is added to specify whether to allow normal users to modify built-in users.

Behavioral changes

  • In this version, the optimization of IN predicate extraction is disabled by default. If large IN queries exist in the business SQL statements and the execution time or memory consumption of these large IN queries causes a bottleneck in the business system, you can set the value of the _enable_in_range_optimization parameter to True to enable the optimization of IN predicate extraction.
  • Since OceanBase Database Enterprise Edition V3.2.4 BP4, the _max_trx_size parameter is replaced with max_trx_part_size.

Parameter changes

Parameter Change type Default value Description
_enable_in_range_optimization New False A tenant-level parameter that specifies whether to optimize the query range of IN predicates.
max_trx_part_size New 0B A cluster-level parameter that specifies the maximum amount of data that can be written by a transaction on a participant. Default value: OB, which specifies not to apply a limit.
_max_trx_size Deprecated 0B This parameter is replaced by max_trx_part_size to ensure compatibility between different versions.
max_trx_2pc_retry_interval New 30s A cluster-level parameter that specifies the maximum message retry interval during the two-phase commit of transactions.
_enable_reserved_user_dcl_restriction New False A cluster-level parameter that specifies whether only a built-in user can modify other built-in users. Default value: False, which specifies not to apply a limit.
_enable_backtrace_function New True A cluster-level parameter that specifies whether the backtrace function takes effect.
_optimizer_better_inlist_costing New False A tenant-level parameter that specifies whether to enable IN expression optimization for the optimizer.
kv_ttl_history_recycle_interval New 7d A tenant-level parameter that specifies the retention period of the historical records of TTL-based deletion tasks.
kv_ttl_duty_duration New [00:00:00, 24:00:00] A tenant-level parameter that specifies the running period for background TTL tasks.
enable_kv_ttl New False A tenant-level parameter that specifies whether to enable background TTL tasks.
_pipelined_table_function_memory_limit New 500 * 1024 * 1024 (500 MB) A tenant-level parameter that specifies the size of memory for the result set of pipelined functions.

System variable changes

Variable Change type Default value Description
_show_ddl_in_compat_mode New 0 Specifies whether to show the result of compatibility with MySQL. After this variable is enabled, show create table/database will show the result of compatibility with MySQL. This is a session-level variable. Default value: 0, which indicates that this feature is disabled.

Notice

The MySQL mode of OceanBase Database has special scalability capabilities. For example, OceanBase Database allows you to add subpartitions, and you can specify Default in a LIST-partitioned table to prevent adding additional partitions. If you use these capabilities to create a table in MySQL mode, the displayed content will be different from the actual schema in Oracle mode of OceanBase Database. Proceed with caution.

Bug fixes

  • Fixed the issue of stack overflow caused by excessive loop iterations in stored procedures with GOTO (Oracle mode) or ITERATE (MySQL mode) statements.
  • Fixed the issue where the memory usage of the SYS500 tenant was high in a liboblog scenario due to a Time Stamp Counter (TSC) clock rollback.
  • Fixed the issue where Error 4377 was returned when partition pruning was triggered by an INSERT statement in non-strict mode.
  • Fixed the issue where Error 4012 was returned when an excessively long JSON string was inserted by using the replace into statement.
  • Fixed the issue where the return result of DBMS_UTILITY.GET_HASH_VALUE(ROWID,1,10000) was incompatible in Oracle mode.
  • Fixed the issue where the 4000 common error was returned for an UPDATE operation that contained subqueries.
  • Fixed the issue where a core dump of the observer process might occur when a stored procedure that contained CursorForLoop was debugged in OceanBase Developer Center (ODC).
  • Fixed the issue where the value of the server_uuid system variable was wrong after a tenant upgrade.
  • Fixed the issue where too many memory resources were occupied when the result sets of pipelined functions were large.
  • Fixed the issue where an error might return during cross-user schema identification if no database was specified for public synonyms in Oracle mode.
  • Fixed the issue where it took a long time to generate an execution plan for the INSERT ALL statement.
  • Fixed the issue where in Oracle mode, the scale and precision of the data returned by the ResultSetMetaData API were inconsistent with those returned in Oracle Database.
  • Fixed the issue where an out-of-memory (OOM) error was returned during package compilation after a memory leak occurred in PL Resolve View.
  • Fixed the issue where an error was returned in querying distinct primary keys and CLOB columns.
  • Fixed the issue where Error 4258 was returned during character set conversion when statistics were collected.
  • Fixed the issue of generating a large query range and causing SQL execution error 4019 Size Overflow in an equijoin scenario where both tables had IN conditions. This issue occurred because duplicate IN predicates were not being eliminated.
  • Fixed the issue where tenant parameters could not be specified if the number of timer tasks on the node exceeded 32 when many tenants existed.
  • Fixed the issue where after the tenant allowlist (ob_tcp_invited_nodes) was set to 1.1.1.1/24, the logon by using 1.1.1.1 failed.
  • Fixed the issue where Error 4019 was returned when the SHOW CREATE TABLE statement was executed on a partitioned table that contained 50,000 partitions.
  • Fixed the issue where a major compaction for the standby tenant timed out due to a TSC time exception in the system.
  • Fixed the issue where Error 5226 was returned when the usage of the plan cache reached the limit because plan cache eviction failed.
  • Fixed the issue where when an exception occurred during a package call, the number of the line where the exception occurred was inaccurately provided by the exception handler.
  • Fixed the issue where an error was returned for a ROWNUM query due to the push-down of the join limit.
  • Fixed the issue where Error 4016 was returned if the base table of the trigger contained hidden columns.
  • Fixed the issue of not being able to display the information of views that reference a DBLink table using the DES command.
  • Fixed the issue where Error 5599 was returned when an array constructor was used in a CREATE USER statement.
  • Fixed the issue where errors might be returned while accessing views that contain synonyms.
  • Fixed the issue where OceanBase Database Proxy (ODP) could not obtain routing information when two synonyms were nested.

V3.2.4 BP3

Version information

  • Release date: April 19, 2023
  • Version: V3.2.4 BP3
  • RPM version: oceanbase-3.2.4.3-103000032023041816

Enhanced features

  • The OBKV connection count feature is added, which simplifies the process for locating OBKV request issues.

    • The GV$OB_KV_CONNECTIONS view is added, which allows you to query all active sessions of the KV class in the current tenant.
    • The V$OB_KV_CONNECTIONS view is added, which allows you to query all active sessions of the KV class on the current OBServer node.
  • The call of the CURRVAL function to obtain the current value of a sequence across OBServer nodes is optimized.

    • In earlier versions, when OceanBase Database Proxy (ODP) connects to an OBServer node, if a route switch occurs between consecutive NEXTVAL and CURRVAL calls, an error is reported when you call CURRVAL on another OBServer node.
    • This version supports cross-route synchronization of CURRVAL calls when ODP connects to an OBServer node. The call of CURRVAL on another OBServer node returns the value obtained by the last NEXTVAL call.

Behavioral changes

  • The INSERT VALUES statement for inserting multiple rows of data in MySQL mode is supported. In MySQL mode, if you do not specify the strict mode for SQL_MODE, when you insert NULL to fields with the NOT NULL constraint, an error is reported if you use INSERT VALUES to insert a single row of data, and the operation succeeds but a WARNING alert is generated if you use INSERT VALUES to insert multiple rows of data, same as in MySQL Database.

  • Sorting for SET QUERY result sets is supported in Oracle mode.

    • The serial execution and sequential output feature of Oracle Database is supported. You can set the tenant- or session-level variable _force_order_preserve_set to enable this feature.
    • For performance considerations, by default, HASH operators, such as set operators like UNION ALL, UNION, MINUS, INTERSECT, and EXCEPT, are used instead of MERGE operators for parallel execution.

Parameter changes

Parameter Change type Default value Description
_large_query_yield_timelimit New 30s The wait timeout period for large queries. It is a cluster-level parameter. Value range: (0ms, + ∞].
_with_subquery New 0 The common table expression (CTE) optimization strategy of the optimizer. It is a tenant-level parameter. Valid values:
  • 0: OPTIMIZE. The optimizer determines whether a CTE is materialized or inlined.
  • 1: MATERIALIZE. The optimizer forcibly materializes CTEs.
  • 2: INLINE. The optimizer forcibly inlines CTEs.
_xsolapi_generate_with_clause New true Specifies whether the optimizer actively extracts CTEs. It is a tenant -level parameter. Valid values: [true, false].
_optimizer_group_by_placement New true Specifies whether the optimizer enables the rewrite feature for GROUP BY PLACEMENT. It is a tenant -level parameter. Valid values: [true, false].

System variable changes

Variable Change type Default value Description
_force_order_preserve_set New false Specifies the rewrite behavior and the plan generation logic of SET QUERY. If this variable is set to true, the branches are executed serially and the result sets are output in sequence. It is a global or session-level variable. Valid values: [true, false].
Note
When this parameter is set to true, the computing performance is affected.

Considerations

The _max_trx_size parameter allows you to limit the transaction size to ensure system stability. If the parameter is set to 0, the transaction size is not limited. The default value is 100M. Observe the following considerations when you configure this parameter:

  1. The _max_trx_size parameter setting does not take effect, except for V2.x and earlier and V3.2.4 and later.
  2. When you upgrade from a version in which this parameter does not take effect to V3.2.4 or V3.2.4 BP, the transaction size is changed from unlimited to a maximum size of 100 MB. If you do not want to limit the transaction size, set this parameter to 0 before the upgrade.

Bug fixes

  • Fixed the issue where the range extraction was abnormal and caused incorrect results when columns C1, C2, and C3 had indexes and an SQL statement contained the (C1 = ? OR C1 = ? ...) AND C2 IN (...) AND C3 ... condition.
  • Fixed the issue where ORA-00600: internal error code, arguments: -4016, Internal error was reported when the SUBSTRB function was used in a DML statement in PL and the parameters included variables defined in PL.
  • Fixed the issue where in Oracle mode, when a package variable was used as the output parameter for internal calls, the stored procedure execution result was incompatible with that of the native Oracle Database.
  • Fixed the issue where an excessive long time was took to get the plan due to the failure to handle UPDATE IGNORE during expression precalculation.
  • Fixed the issue where backup pieces were not deleted as expected when an automatic cleanup task was normally scheduled.
  • Fixed the issue where a memory leak problem occurred when a SELECT statement was parsed in an INSERT ALL statement.
  • Fixed the issue where the execution result was not as expected due to abnormal return results of the expression when a filter condition was pushed down.
  • Fixed the issue where some indexes were in the abnormal state after physical restore.

V3.2.4 BP2

Version information

  • Release date: February 28, 2023
  • Version: V3.2.4 BP2
  • RPM version: oceanbase-3.2.4.2-102000042023022717

Enhanced features

  • The system package UTL_RAW in Oracle mode supports the CAST_TO_NVARCHAR2() function, which converts RAW values into NVARCHAR2 values.
  • DBLinks support DNS resolution in Oracle mode.
  • The system functions XMLAGG(), XMLPARSE(), and XMLELEMENT() are supported in Oracle mode.
  • The FROM_BASE64() and TO_BASE64() functions are supported in MySQL mode.
  • The compatibility with the system variables DEFAULT_STORAGE_ENGINE and EVENT_SCHEDULER is improved in MySQL mode.
  • The value 11 is available for the REQUEST_TYPE field in the V$OB_SQL_AUDIT view. This value indicates that the SQL statement is executed in PL.

Considerations

  • ArrayBinding is not recommended for batch insertion in this version. We recommend that you set ob_enable_batched_multi_statement to False.
  • When you upgrade OceanBase Database Enterprise Edition from V3.2.4 or V3.2.4 BP1 to V3.2.4 BP2, election without leader may occur during the upgrade. After all OBServer nodes are started, normal election resumes and the cluster is upgraded.

Bug fixes

  • Fixed the issue where when the number of SSTable macroblocks was too large and more than 32 MB of data was written in the slog file, an error was reported and the major compaction of the cluster was stuck.
  • Fixed the issue where the execution result was wrong in MySQL mode because the filters applied by the NEST LOOP JOIN operator was abnormal.
  • Fixed the issue where when the macroblock reuse logic was abnormal, a large number of macroblocks were rewritten, resulting in excessive I/Os during the major compaction of the cluster.
  • Fixed the issue where when an SQL statement had four or more index columns in a WHERE clause and an index was hit and contained in expr, the result set returned by the query was incorrect in some scenarios.
  • Fixed the issue where when data of OceanBase Database V2.2.77 was restored by using OceanBase Database V3.2.4, the leader was stuck.
  • Fixed the issue where in Oracle mode, when AUTO COMMIT was disabled, after some data was inserted, the SELECT statement in a user-defined function (UDF) could not read uncommitted data.
  • Fixed the issue where in Oracle mode, when AUTO COMMIT was enabled, after a transaction was manually started and the executed PL package contained DML statements, the transaction was automatically committed.

V3.2.4 BP1

Version information

  • Release date: January 9, 2023
  • Version: V3.2.4 BP1
  • RPM version: oceanbase-3.2.4.1-101000052023010822

Enhanced features

  • Security optimization

    • You can change the AccessKey ID and AccessKey Secret during data backup and restore. The backup feature of OceanBase Database allows you to specify an Alibaba Cloud Object Storage Service (OSS), Tencent Cloud Object Storage (COS), or Huawei Object Storage Service (OBS) bucket as the backup destination. However, you cannot modify the access_id or access_key parameter of the backup destination during the backup. If the AccessKey ID or AccessKey Secret is changed, you must stop the log backup and change the backup directory. Therefore, this version provides the ALTER SYSTEM change external_storage_dest PATH[=]'xxx?host=xxx' set ACCESS_INFO[=]'access_id=xxx&access_key=xxx'; command for you to modify the AccessKey ID and AccessKey Secret of the backup destination. The relevant content in GConf is updated and saved accordingly. Observe the following considerations when you use this command:

      • Before you run the command to update the AccessKey ID and AccessKey Secret for accessing the OSS, COS, or OBS bucket, we recommend that you stop the ongoing second backup task. We also recommend that you delete the old AccessKey ID and AccessKey Secret one hour later after you run the command.
      • If you modify the AccessKey ID and AccessKey Secret during a second backup task, and the task is stuck, you must forcibly cancel the task and change the directory to resume to task.
    • The password information configured by using a DBLink can be encrypted for storage.

    • Remote Procedure Call (RPC) authentication is supported for communication between OBServer nodes.

    • Transparent data encryption (TDE) is integrated into Alibaba Cloud Key Management Service (KMS).

  • Monitoring statistics optimization: Transaction time statistics and SQL execution time statistics are added to the v$sysstat view.

    • Transaction time statistics metrics include sp trans total used time and distributed trans total used time.
    • SQL execution time statistics metrics include sql local execute time, sql remote execute time, and sql distributed execute time.
  • Compatibility with MySQL PL syntaxes: GET DIAGNOSTICS, GET STACKED DIAGNOSTICS CONDITION, DECLARE CONTINUE HANDLER, SIGNAL SQLSTATE, and DEFINER syntaxes are supported.

  • Performance optimization: You can use arrays to execute simple statements such as INSERT...VALUES, UPDATE, and DELETE in batches. This improves the batch execution performance by about 4 times.

Compatibility changes

  • The default value of the schema_history_expire_time parameter is changed from 7d to 30d.
  • The default value of the ob_esi_session_timeout parameter is changed from 1m to 10m.
  • The rpc_client_authentication_method parameter is added to specify the security authentication method of the RPC client. The setting takes effect immediately. Valid values are NONE, PLAIN_KEY, SSL_NO_ENCRYPT, and SSL_IO. The default value is NONE.
  • The rpc_server_authentication_method parameter is added to specify the security authentication method of the RPC server. The setting takes effect immediately. Valid values are NONE, ALL, PLAIN_KEY, SSL_NO_ENCRYPT, and SSL_IO. The default value is ALL.

Bug fixes

  • Fixed the issue where in Oracle mode, Error 4179 was returned when a cursor for looping operations was used in a package.
  • Fixed the issue where a timeout error occurred when deleting data from a table with foreign keys, where the internal execution flow triggered an exception in parallel while processing the foreign keys.
  • Fixed the issue where creating a new tenant resulted in an error of insufficient resources due to abnormal resource release after tenant release.
  • Fixed the issue where when an execution plan hit the plan cache, the execution result of MERGE INTO was incorrect.
  • Fixed the issue where memory leak occurred when indexes were created on JSON generated columns.

Considerations

  • To use Key Management Service (KMS), upgrade liboblog to V3.2.4.0 or later and then upgrade OceanBase Database to V3.2.4 BP1.
  • If a large query triggers a deadlock in a scenario where ArrayBinding or CREATE TABLE AS SELECT is used, we recommend that you increase the value of the large_query_threshold parameter to avoid triggering deadlocks.

V3.2.4

Version information

  • Release date: November 1, 2022
  • Version: V3.2.4
  • RPM version: oceanbase-3.2.4.0-100000072022102819

Overview

Compared with V3.2.3, OceanBase Database V3.2.4 improves the compatibility and stability of the database kernel to meet the production and testing requirements of customer systems. Core enhancements include:

  • Enhanced compatibility with MySQL

    The geographic information system (GIS) and MySQL binlog parsing are supported. The DBMS_RESOURCE_MANAGER system package is added.

  • Enhanced compatibility with Oracle

    The DBMS_SCHEDULER system package is added. System package functions are supplemented.

  • Kernel enhancements

    SQL rule-based resource isolation, the IPv6 protocol, backup to OBS, log optimization, transaction size configuration, and configuration of the number of logon threads are supported.

New features

Enhanced compatibility

Compatibility with MySQL
  • Support for GIS

    GIS provides the storage, computing, and indexing capabilities for spatial objects such as points, lines, planes, and complex spatial objects. GIS is widely applied in the transportation industry and can help quickly build spatial computing capabilities. GIS is supported since OceanBase Database V3.2.4. GIS in OceanBase Database adopts the quadtree-based indexing solution and supports the GIS data types of MySQL 8.0, the management and caching of spatial reference system (SRS) metadata, quadtree-based spatial indexes, single-value types (GEOMETRY, POINT, LINESTRING, and POLYGON), and multi-value types (MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, and GEOMETRYCOLLECTION). The spatial computing functions commonly used in MySQL 8.0 are also implemented. For more information, see Functions for spatial computing.

  • Support for MySQL binlog parsing

    The OceanBase CDC data synchronization solution supports MySQL binlogs and allows popular applications, such as Canal, Debezium, and Flink CDC, to generate and parse binlogs in OceanBase Database. The OBServer node must support binlog-related system variables such as binlog_format, binlog_row_image, log_bin, and server_uuid. The REPLICATION SLAVE and REPLICATION CLIENT privileges can be set. OceanBase CDC parses clogs in OceanBase Database into binlogs for subscription and consumption by downstream products. For more information, see binlog_row_image.

  • Addition of the DBMS_RESOURCE_MANAGER system package

    The DBMS_RESOURCE_MANAGER system package is added for creating and maintaining resource consumer groups, resource management plans, and binding rules of resource consumer groups. More functions are supported, such as CREATE_CONSUMER_GROUP, CREATE_PLAN, and SET_CONSUMER_GROUP_MAPPING.

Compatibility with Oracle
  • Addition of the DBMS_SCHEDULER system package

    The DBMS_SCHEDULER system package is added for managing scheduled tasks. More functions are supported, such as CREATE_JOB, CREATE_PROGRAM, and DEFINE_PROGRAM_ARGUMENT.

  • Supplementation of system package functions

    • The DBMS_SESSION.SET_CONTEXT function is supplemented for setting or resetting the value of the context attribute.
    • The DBMS_SESSION.CLEAR_CONTEXT function is supplemented for clearing the specified context.
    • The UTL_RAW.CAST_TO_BINARY_INTEGER function is supplemented for converting the RAW binary representation of a BINARY_INTEGER value into a BINARY_INTEGER value.

Kernel enhancements

  • Support for SQL rule-based resource isolation

    In real practice, more fine-grained control of resource isolation is required for business. For example, different SQL statements are executed by using different resource specifications for isolation. This helps allocate and isolate resources for business systems such as OLAP and OLTP, and reduces the mutual impact between business systems.

    OceanBase Database V3.2.4 supports creating resource groups and binding users to resource groups. When a user executes a business SQL statement, OceanBase Database allocates the corresponding resource group based on the predefined SQL rules to help the user define a business resource isolation plan. At present, the resource isolation plan applies only to CPU resources. For more information, see Multi-tenant resource isolation.

  • Support for the IPv6 protocol

    IPv6 is widely applied in customer projects as it gains popularity among communications network suppliers and terminal vendors. OceanBase Database V3.2.4 and related components, such as ODP and JDBC, support IPv6. OceanBase clusters support both IPv4 and IPv6 TCP/IP connections. Before you use IPv6, make sure that the operating system of your server is configured to support IPv6. For more information, see IS_IPV6.

  • Support for backup to OBS

    Backup and restore is a core feature for ensuring the high availability of OceanBase Database. OceanBase Database supports three backup media: Alibaba Cloud Network File System (NFS), Alibaba Cloud Object Storage Service (OSS), and Tencent Cloud Object Storage (COS). OceanBase Database supports backup to HUAWEI CLOUD Object Storage Service (OBS) since V3.2.4. You can specify the backup destination (backup_dest) to back up data and log files to OBS. For more information, see Preparations for backup.

  • Log optimization OceanBase Database V3.2.4 optimizes log output in the following aspects:

    • Log level definition: The DIAG log level is added. WARN and ERROR logs that do not need to be perceived by users are classified into DIAG logs. The levels are adjusted for O&M-oriented WARN and ERROR logs that need to be retained.

      Log level Intended audience Definition Original log level
      ERROR DBA or users The OBServer node cannot provide normal services. For example, the disk is full or the listening port is occupied. An ERROR log may also be generated when an error is returned during an internal check in the background. For example, 4377 indicates a DML defensive check error, and 4103 indicates a data checksum error. In this case, manual intervention is required. /
      WARN DBA or users An unexpected scenario occurs. The OBServer node can provide services, but the behavior is not as expected. For example, a write throttling warning. /
      INFO DBA or users System status changes. INFO
      EDIAG R&D Error diagnosis information for troubleshooting. This log level indicates an unexpected logical error. For example, function parameters are not as expected. ERROR
      WDIAG R&D Warning diagnosis information for troubleshooting. This log level indicates an expected error. For example, a function fails to return a value. WARN
      TRACE R&D Task-level diagnosis information. TRACE
      DEBUG R&D Debugging details. DEBUG
    • Error code association: Error messages are classified and error codes are improved. A response error code is defined for each warning and error. You can retrieve documents based on an error code to find the solution.

    • Throttling by error code: WDIAG logs are throttled by error code. For throttled logs, only the error code and the number of throttled logs are displayed. The diag_syslog_per_error_limit parameter is added for controlling this throttling feature. By default, 200 DIAG logs per second are allowed for each error.

    • Monitoring log removal: The dump tenant info, memory info, and easy stat log entries are removed from log files for separate management.

    • Log file self-description: The server address, host type, CPU type, operating system version, OBServer version, and time zone are recorded in the header of each log file.

  • Other feature enhancements

    • You can configure the transaction size by using the _max_trx_size parameter.
    • You can configure the number of logon threads by using the sql_login_thread_count parameter.
    • You can set table-level parallel hints. For example, select /*+ parallel(t1, 8) */ from t1;.

Compatibility changes

Parameters

Parameter Change type Default value New default value Description
enable_cgroup New / True Specifies whether to enable the control group feature.
sql_login_thread_count New / 0 The number of threads for processing logon requests. The default value is 0, which indicates that the number of threads is dynamically adjusted.
ob_query_switch_leader_retry_timeout New / 0us The longest retry time for a failed query. The default value is 0us, which indicates that the retry timeout check is disabled.
diag_syslog_per_error_limit New / 200 The number of diagnostic logs for each error code per second.
ob_esi_syslog_level Modified INFO WDIAG The log level of independent subprocesses.
syslog_level Modified INFO WDIAG The level of system logs.

System changes

Parameter Change type Recommended value Description
binlog_format New ROW The supported binlog format. This parameter takes effect when log_bin is set to ON.
binlog_checksum New CRC32 The supported binlog checksum.
binlog_rows_query_log_events New OFF Specifies whether to write row query log events into the binlog. This parameter applies to the row-based logging.
log_bin New ON The supported binlog enabling status.
server_uuid New Generated upon tenant creation The instance UUID.

Behavioral changes

  • Differences between the new system log levels used in OceanBase Database V3.2.4 and the log levels in earlier versions:
    • The log levels are ERROR, WARN, INFO, EDIAG, WDIAG, TRACE, and DEBUG in descending order of priority.

    • The WARN log level in earlier versions changes to the WDIAG level in V3.2.4. Therefore, WARN logs in earlier versions are generated as ERROR logs in V3.2.4.

Upgrade notes

  • An upgrade from V3.2.1, V3.2.2, or V3.2.3 to V3.2.4 is supported. However, an upgrade from V3.2.3 BP6 and later to V3.2.4 is not supported.

  • An upgrade from V3.1.2 to V3.2.4 is supported. You must download the software packages V3.2.0, V3.2.1, V3.2.2, and V3.2.3, and upload them to OCP.

  • An upgrade from V2.2.77 is supported. You must upgrade OceanBase Database to V3.1.2 first and then to V3.2.4.

Recommended versions of tools

The following table describes the recommended versions of components used with OceanBase Database V3.2.4.

Component Version
ODP V3.2.8
OCP V3.3.4
ODC V4.0.0
OMS V3.4.0
OBCI V2.0.2
ECOB V1.1.6
JDBC V2.2.11
OBClient V2.1.1.3

Considerations

The open_cursors parameter specifies the maximum number of open cursors that a session can have at once. The default value is 50. OceanBase Database V3.2.4 changes the maximum number of prepared statements for a single session. Therefore, if you upgrade your database to V3.2.4, you must determine whether to increase the value of open_cursors to avoid errors when prepared statements are executed.

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V3.2.4 BP4
Version information
Enhanced features
Behavioral changes
Parameter changes
System variable changes
Bug fixes
V3.2.4 BP3
Version information
Enhanced features
Behavioral changes
Parameter changes
System variable changes
Considerations
Bug fixes
V3.2.4 BP2
Version information
Enhanced features
Considerations
Bug fixes
V3.2.4 BP1
Version information
Enhanced features
Compatibility changes
Bug fixes
Considerations
V3.2.4
Version information
Overview
New features
Compatibility changes
Upgrade notes
Recommended versions of tools
Considerations