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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 V2.2.77

Last Updated:2023-10-24 09:23:04  Updated
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V2.2.77 BP17
Version information
Enhanced features
Parameter changes
Behavioral changes
Bug fixes
Upgrade and limitations
V2.2.77 BP16
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Enhanced features
Bug fixes
Upgrade and limitations
V2.2.77 BP15
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Enhanced features
Compatibility changes
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Upgrade and limitations
V2.2.77 BP14
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Enhanced features
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V2.2.77 BP13
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V2.2.77 BP12
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V2.2.77 BP11
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V2.2.77 BP10
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V2.2.77 BP17

Version information

  • Release date: May 19, 2023
  • Version: V2.2.77 BP17
  • RPM version: oceanbase-2.2.77-117000112023051914

Enhanced features

Security enhancement: The _enable_reserved_user_dcl_restriction parameter is provided to control whether general users can modify built-in users.

Parameter changes

Parameter Change type Default value Description
_enable_reserved_user_dcl_restriction New false Specifies whether built-in users can be modified only by built-in users. This is a cluster-level parameter. Valid values: true and false.[]

Behavioral changes

  • The initial value of the time_zone system variable is changed from +8:00 to +08:00.
  • The SELECT statements cannot be sent in PS mode. In an earlier version, SELECT statements can be sent, but 0 rows are returned.

Bug fixes

  • Fixed an issue that when the index key of an index table contains a NULL value, which is contained in the extracted query range of the SQL query, the query result may be incorrect.
  • Fixed an issue that the asynchronous refresh of the location cache may fail due to the leader switchover of the __all_core_table or __all_root_table table. This causes SQL execution to time out.
  • Fixed an issue that when a HASH JOIN operator appears in the right branch of a SUBPLAN FILTER or NESTED-LOOP JOIN operator, and the left branch contains a large number of rows, SQL execution takes a long time and consumes a large amount of memory space.
  • Fixed an issue that if the view in an SQL query is the same as that in its subquery, and the predicates are pushed down to a wrong view, the query result set may be inconsistent with that of an Oracle database.
  • Fixed an issue that if you use a constructor as the default value of a composite data type in the PL package, the SYS500 tenant consumes a large amount of memory space.
  • Fixed an issue that if the PL package does not exit and the trigger is called multiple times, the memory usage continues to increase.
  • Fixed an issue that a memory leak is caused by a cursor.
  • Fixed an issue that the major compaction of a standby cluster times out.
  • Fixed an issue that cache miss occurs and the execution of INSERT statements is slow when the not_param identifier of the system is incorrectly set.
  • Fixed an issue that if a PACKAGE variable is used as the output parameter for internal calls in Oracle mode, the execution results of stored procedures are incompatible with that of an Oracle database.
  • Fixed an issue that after a predicate is pushed down, the execution result is not as expected due to abnormal return results of the expression.
  • Fixed an issue that a memory leak occurs when a SELECT statement is parsed in an INSERT ALL statement.
  • Fixed an issue that if the ob_tcp_invited_nodes variable contains a subnet mask, an error occurs during the matching of IP addresses against the allowlist.
  • Fixed an issue that if a node is killed by running the kill -9 command, but the server is not added to the session blocklist, the backup and restore job fails.
  • Fixed an issue that if the deduction of the IN predicate is performed again when an IN predicate already exists in the table, a large query range is extracted and an error is returned during SQL execution.
  • Fixed an issue that if the package called contains synonyms, the compilation of the caller package fails.
  • Fixed an issue that the execution of a unit migration task is slow in a standby cluster.
  • Fixed an issue that if you specify an alias for a synonym view, an error is returned when you access the synonym view.
  • Fixed an issue that if you use an analytic function (also known as a window function) expression as the input parameter of a user-defined function (UDF), the 4016 error is returned.
  • Fixed an issue that some indexes are abnormal after a successful physical restore.
  • Fixed an issue that an error is returned during the execution of the REGEXP_REPLACE expression due to multiple implicit conversions of unmatching field types.
  • Fixed an issue that the content read from read-only views cannot be written to other tables.
  • Fixed an issue that the value of storage space occupied by backup files is inaccurate in the system table.
  • Fixed an issue that in PS mode, the prefix index is parsed based on the LIKE expression without verifying whether the LIKE pattern meets the constraint, which causes an error during the execution of stored procedures.
  • Fixed an issue that after an upgrade, if the ANALYZE statement is used against a table of an earlier version, an error is returned.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.
  • If you enable the dynamic AccessKey ID (AK)/AccessKey secret (SK) setting feature for data backup and restore, you cannot upgrade OceanBase Database to V3.x.

V2.2.77 BP16

Version information

  • Release date: February 14, 2023
  • Version: V2.2.77 BP16
  • RPM version: oceanbase-2.2.77-116000022023021412

Enhanced features

The GROUP COMMIT capability is supported for OBKV to update hotspot rows. To better handle highly concurrent updates of hotspot rows, the server that supports GROUP COMMIT aggregates concurrent updates to prevent repeated row lock application and release for each operation. This saves the wait time due to row lock contention, and speeds up the hotspot row update.

Bug fixes

  • Fixed an issue that the execution of the USE DATABASE statement triggers implicit commit of transactions.
  • Fixed an issue that the SELECT statement in PL cannot read the data that has not been committed.
  • Fixed an issue that some indexes are abnormal after a successful physical restore.
  • Fixed an issue that when you create a view, you must also specify an alias for ROWID in the SELECT clause even if you have specified column names.
  • Fixed an issue that the BATCH GET request of HBaseAPI takes a long time to complete.
  • Fixed an issue that the update of a primary key column in a TableAPI operation results in data inconsistency between the primary table and the index table.
  • Fixed an issue that an error is returned when TableAPI automatically updates fields with default values of CURRENT_TIMESTAMP or ON UPDATE CURRENT_TIMESTAMP.
  • Fixed an issue that an error is returned when the estimated result length of the REGEXP_REPLACE function is greater than the maximum allowable value because of excessively strict program check.
  • Fixed an issue that the binary comparison of the FIND_IN_SET(binary 'b','a,B,c,d') function does not take effect in MySQL mode.
  • Fixed an issue that the execution of the FIND_IN_SET function is slow in MySQL mode.
  • Fixed an issue that the backup_piece files that are expected to be cleaned up are not deleted in a normally scheduled automatic cleanup task.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • If you have enabled the dynamic AccessKey ID (AK)/AccessKey secret (SK) setting feature for data backup and restore, you cannot upgrade OceanBase Database to V3.x.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP15

Version information

  • Release date: January 10, 2023
  • Version: V2.2.77 BP15
  • RPM version: oceanbase-2.2.77-115000012023010607

Enhanced features

The FROM_BASE64() and TO_BASE64() functions are supported in MySQL mode.

Compatibility changes

In MySQL mode, the ORDER BY or LIMIT operator cannot be used for multi-table updates, which is consistent with MySQL.

Bug fixes

  • Fixed an issue that when you use an IN expression to query a partitioned table, the calculated result set is incorrect.
  • Fixed an issue that the migration of an empty resource unit causes the leader to get stuck.
  • Fixed an issue that when an execution plan hits the plan cache, the execution result of MERGE INTO is incorrect.
  • Fixed an issue that a memory leak occurs when indexes are created on JSON generated columns.
  • Fixed an issue that backup sets fail to be cleared during automatic backup clearing.
  • Fixed an issue that in Oracle mode, when a package uses a cursor for loop operations, Error 4179 is returned.
  • Fixed an issue that the standby database fails to restart due to an slog replay error.
  • Fixed an issue that errors are returned when the LPAD function processes special characters whose ASCII codes are 0x03, 0x04, 0x05, and 0x06.
  • Fixed an issue that during the clearing of expired backups, the clearing task remains in the DOING state and cannot be stopped.
  • Fixed an issue that if the execution of a transaction is interrupted, the transaction ID recorded in SQL audit logs is incorrect.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.
  • If you have enabled the dynamic AccessKey ID/AccessKey Secret setting feature for data backup and restore, an upgrade to V3.x is not supported.

V2.2.77 BP14

Version information

  • Release date: December 04, 2022
  • Version: V2.2.77 BP14
  • RPM version: oceanbase-2.2.77-114000072022120410

Enhanced features

  • 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 the task.
  • The following three fields are added to the v$sysstat view to optimize hotspot row observation.

    • TRANS_ELR_ENABLE_COUNT: the number of transactions for which early lock release (ELR) can be enabled.
    • TRANS_ELR_UNABLE_COUNT: the number of transactions for which ELR is disabled.
    • READ_ELR_ROW_COUNT: the number of rows that support ELR. The number of rows that support ELR is increased.
  • ob_admin supports OBS.

Bug fixes

  • Fixed an issue that the execution of the to_hex() function during stored procedure debugging causes server failures.
  • Fixed an issue that when system variables fail to be loaded, the session is abnormally released, and this causes a server failure.
  • Fixed an issue that the time zone used by the backup logic is different from that used by the restore logic. As a result, the default values of restored table fields lag behind those of the original table by 8 hours.
  • Fixed an issue that when the _enable_fulltext_index parameter is set to OFF, creating a full-text index succeeds, which is abnormal.
  • Fixed an issue that when the special characters "+/" are used in a LIKE statement, the query result of an index scan is incorrect.
  • Fixed an issue that when an inner join subquery is executed, the query results in OceanBase Database and MySQL Database are inconsistent.
  • Fixed an issue that in an outer join, the number of rewritten rows is inconsistent with the number of queried rows.
  • Fixed an issue that the number of constraints on the CONCAT() function is negative, which is abnormal.
  • Fixed an issue that when the batch deletion operation of COS is called, the system cannot determine whether all objects are deleted.
  • Fixed an issue that when you delete a large number of Fail to erase key from cache entries from the observer.log file, an error is returned.
  • Fixed an issue that in non-strict mode, the execution result of creating an index is different from that of adding an index.
  • Fixed an issue that the use_hash_aggregation hint does not take effect.
  • Fixed an issue that after schema history file recycling is enabled, physical restore may fail.
  • Fixed an issue that the backup may fail due to an incorrect session count in the independent backup and restore subprocess.
  • Fixed an issue that during the procedural language (PL) execution by using the OCI_BATCH_ERRORS handle, a data storage error occurs due to primary key conflicts.
  • Fixed an issue that if slogs and SSTables are located on the same disk, the clog disk is almost full error is returned during slog initialization.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.
  • If you have enabled the dynamic AccessKey ID/AccessKey Secret setting feature for data backup and restore, an upgrade to V3.x is not supported.

V2.2.77 BP13

Version information

  • Release date: August 26, 2022

  • Version: V2.2.77 BP13

  • RPM version: oceanbase-2.2.77-113000052022082622

Enhanced features

  • Adding partitions is supported in specific scenarios. You can add partitions at the beginning or in the middle of RANGE-partitioned tables. When you add a partition, make sure that no data is written to this partition. You can enable this feature by using the tenant-level parameter _enable_add_between_range_partitions.
  • Cluster-level parameters of a specific OBServer can be modified by using ob_admin. However, tenant-level parameters cannot be modified for a specific OBServer.
  • Backup files on Tencent Cloud COS can be tagged to facilitate file management.

Bug fixes

  • Fixed an issue that the cluster restart times out due to an excessive number of schema history records.
  • Fixed an issue that in MySQL mode, an error is returned for invalid characters generated during the conversion of the GBK character set by calling the CONVERT() function. In this version, the invalid characters are converted to 0x3F, which is compatible with MySQL.
  • Fixed an issue that in the primary-standby deployment mode, records in the virtual table __all_server_event_history expand fast due to frequent execution of the ALTER SYSTEM CHANGE TENANT operation on the primary database.
  • Fixed an issue that during the execution of a distributed plan, when one OBServer node fails, the execution of SQL statements on other OBServer nodes hangs until timeout.
  • Fixed an issue that when an equivalent condition is used to detect the case sensitivity of the collation, the returned result set is wrong because an execution plan is incorrectly hit.
  • Fixed an issue that when a backup task is forcibly canceled, the backup status stays in Stopping.
  • Fixed an issue that when the INSERT...ON DUPLICATE KEY UPDATE statement is executed, an error indicating duplicated primary keys is returned.
  • Fixed an issue that an error is returned during the execution of a nested aggregate operator that contains Distinct.
  • Fixed an issue that invalid log information about RPC communication between OBServer nodes is deleted.
  • Fixed an issue that when the __min_full_resource_pool_memory parameter is set to an abnormal value, the OBServer node can still be started.
  • Fixed an issue that when the LAST_INSERT_ID() function is called within a stored procedure, a invalid execution result is generated.
  • Fixed an issue that the 4016 error is returned when a partition is truncated.
  • Fixed an issue that an error occurs for the data of the net_wait_time field in the gv$sql_audit view.
  • Fixed an issue that when the weak_read_version_refresh_interval parameter is set to 0, the data in partitions is not synchronized.
  • Fixed an issue that the query timeout hint added to the cursor of a stored procedure does not take effect.
  • Fixed an issue that in Oracle mode, when a prepared statement is enabled, the return value of the NUMTODSINTERVAL() function is truncated to a specific precision.
  • Fixed an issue that after a partition is dropped or truncated, the locality change is suspended due to duplicate global indexes.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP12

Version information

  • Release date: June 14, 2022

  • Version: V2.2.77 BP12

  • RPM version: oceanbase-2.2.77-20220612090508

Bug fixes

  • Fixed an issue that in Oracle mode, when you create a stored procedure with the specified character set GBK, the OBServer node becomes suspended unexpectedly in the SQL prepare phase.
  • Fixed an issue that in MySQL mode, an error is returned because the Limit operator does not support character type conversion.
  • Fixed an issue that when the system performs a follower-to-leader switchover during a major compaction, the SQL statement is rolled back because the cached route is inaccurate. This causes a long execution time.
  • Fixed an issue that Error 4007 is returned when the DBMS_LOB.SUBSTR system package is executed in Oracle mode.
  • Fixed an issue that the queue_time field is displayed as a negative value in the v$sql_audit view.
  • Fixed an issue that in the sys tenant, the resource specifications are not restored to the default settings after a unit is removed.
  • Fixed an issue that when the input parameter is converted during the execution of a stored procedure, the following error is returned: value too large for column.
  • Fixed an issue that in multi-table join queries, the CPU utilization is high when the join key has an index and a ROWNUM or LIMIT operator.
  • Fixed an issue that when a null condition is used to query the INFORMATION_SCHEMA.COLUMNS view, incorrect results are returned.
  • Fixed an issue that the observer process unexpectedly exits due to an exception occurring in table access by global index primary key. This is caused because the background thread does not initialize the tenant context.
  • Fixed an issue that the observer process unexpectedly exits because the cluster is stopped while data is written to Tencent Cloud Object Storage (COS) or Alibaba Cloud Object Storage Service (OSS).
  • Fixed an issue that a syntax error is returned when the DBMS_LOB system package is executed to insert data.
  • Fixed an issue that the logs of the RootService node repeatedly report errors because an exception occurs when an index is created.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.
  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP11

Version information

  • Release date: May 2, 2022

  • Version: V2.2.77 BP11

  • RPM version: oceanbase-2.2.77-20220502140811

Enhanced features

  • The integration of the transparent data encryption (TDE) feature with the Alibaba Cloud Key Management Service (KMS) system is supported.

  • The performance of non-blocking Table API queries is improved.

  • The maximum value of the in(values) query is optimized to make it compatible with MySQL.

  • Filtering by tenant is supported by liboblog to synchronize only logs of the specified tenants.

  • Returning the synchronization timestamps of logs is supported by liboblog.

Bug fixes

  • Fixed an issue that in MySQL mode, an error is returned during the parsing of the GROUP BY expression because of unclear semantics. In this version, the expression from the selection list is used to avoid errors.

  • Fixed an issue that in MySQL mode, an error is returned for invalid characters generated during the conversion of the GBK character set by calling the CONVERT() function. In this version, the invalid characters are converted to 0x3F, which is compatible with MySQL.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP10

Version information

  • Release date: January 17, 2022

  • Version: V2.2.77 BP10

  • RPM version: oceanbase-2.2.77-20220116224111

Enhanced features

  • The tag cleanup mode is supported in OSS.

  • The USERENV('SID') and USERENV('LANGUAGE') functions are supported in Oracle mode.

  • When the backup space reaches 100%, you can delete obsolete backup files.

  • The stability and performance of the queuing table are improved.

  • The streaming compression algorithm, which is not supported for clog compression, is removed.

  • The 4 KB aligned writes of disk DIRECT_IO are supported.

Compatibility changes

  • By default, the auto_refresh_location_cache parameter is set to true to enable the balance strategy for partition replicas.

  • By default, the schema_history_recycle_interval parameter is set to true to enable the periodic cleanup of expiry records in the system table by background threads.

Bug fixes

  • Fixed an issue that the column type in the view of null columns is NULL, but that in the Oracle database is char(0).

  • Fixed an issue that in the gv$sql_audit view, the maximum length of the QUERY_SQL column is not 64 KB.

  • Fixed an issue that in Oracle mode, a false positive error is returned, which indicates that the total row length of all columns exceeds the value of the OB_MAX_USER_ROW_LENGTH parameter.

  • Fixed an issue that the index creation fails when the GBK character set is used.

  • Fixed an issue that the statistics of a tenant recovered by using the backup and restore feature are not promptly updated.

  • Fixed an issue that the error not support is returned when you set the secure_file_priv parameter after the connection is created by using the IP address 127.0.0.1.

  • Fixed an issue that an error is returned for incorrect calculation of string length when the CREATE TABLE statement involves the setting of variable values.

  • Fixed an issue that the error Column length too big for column is returned during the length check of the LOB columns.

  • Fixed an issue that an error is returned during the execution of the ALTER TABLE DROP COLUMN statement due to the delayed deletion of physical backups.

  • Fixed an issue that when the sql_auto_is_null parameter is set to ON, the error Invalid Argument is returned during a query where the auto-increment columns need to be identified.

  • Fixed an issue that in Oracle mode, no privilege is provided to control the TRUNCATE DLL operation.

  • Fixed an issue that the creation of a global index fails if the process of an OBServer node exits.

  • Fixed an issue that the __all_virtual_memory_info table displays incomplete tenant information.

  • Fixed an issue that the try_cnt column of the gv$sql_audit view shows inaccurate statistics.

  • Fixed an issue that in Oracle mode, the TO_CHAR() function cannot recognize the date format.

  • Fixed an issue that an error occurs when checking is conducted for the index created on a column of the CHAR type in Oracle mode.

  • Fixed an issue that all rows are NULL after the LEFT JOIN UPDATE on multiple tables.

  • Fixed an issue that in PL mode, the observer process unexpectedly exits due to the existence of the PRINT LOB data type.

  • Fixed an issue that the observer process unexpectedly exits because the LIKE clause in the SQL statement exceeds 250 KB in length.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP9

Version information

  • Release date: November 19, 2021

  • Version: V2.2.77 BP9

  • RPM version: oceanbase-2.2.77-20211119120733

Bug fixes

  • Fixed an issue that the 4038 error is returned at the close phase of parallel execution.

  • Fixed an issue that when PL debugging is performed in the OceanBase Developer Center (ODC) console, resources for debugging cannot be quickly released if ODC directly exits.

  • Fixed an issue that the client session is disconnected when the memory request fails at the SQL PARSE phase.

  • Fixed an issue that when a temporary table is created and added with constraints, the cluster is hung if a constraint of the temporary table has the same name as that of a non-temporary table.

  • Fixed an issue that the MERGE INTO (SELECT *) statement is incompatible with Oracle.

  • Fixed an issue that in Oracle mode, the ALL_TAB_PARTITIONS view displays partitions in an unordered way.

  • Fixed an issue that the 4016 error is returned during the execution of the REPLACE INTO statement.

  • Fixed an issue that the gv$sql_audit view displays inaccurate QUEUE_TIME and RETRY_CNT statistics.

  • Fixed an issue that the incorrect FILE HANDLE is obtained when the NFSv4 protocol is used for backup.

  • Fixed an issue that the gv$sql_audit view displays the password for user creation in plaintext.

  • Fixed an issue that if the base table of the gv$sql_audit view does not exist, the value of elapsed_time in the recorded query information is 0.

  • Fixed an issue that in Oracle mode, the pivot and unpivot clauses are incompatible with Oracle.

  • Fixed an issue that the restart of the observer process keeps failing because it cannot be replayed after the restart, which is caused by the reuse of old slogs due to insufficient storage space.

  • Fixed an issue that when the SHOW TABLE STATUS statement is executed to query a partitioned table, the result is NULL.

  • Fixed an issue that in Oracle mode, the error unknown timezone is returned for the OBClient connection after you specify the global time_zone system variable.

  • Fixed an issue that in MySQL mode, the user privileges on a table remain valid after the table is deleted.

  • Fixed an issue that some IP addresses in the gv$sql_audit view are parsed into 0.0.0.0.

  • Fixed an issue that in Oracle mode, an error is returned when the SELECT * FROM (GENERATED TABLE) statement is executed due to duplicate column names.

  • Fixed an issue that the BIT data type is incompatible with MySQL.

  • Fixed an issue that the observer process unexpectedly exits when it reads the configuration file during startup.

  • Fixed an issue that the observer process unexpectedly exits during the data backup to OSS.

  • Fixed an issue that the observer process unexpectedly exits during the conversion of the SET/ENUM/LOB data types.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP8

Version information

  • Release date: October 15, 2021

  • Version: V2.2.77 BP8

  • RPM version: oceanbase-2.2.77-20211117180427

Enhanced features

The internal __ALL_VIRTUAL_PROCESSLIST table is provided to display the transaction timeout status.

Bug fixes

  • Fixed an issue that in the parallel SQL execution framework, the SELECT FOR UPDATE statement causes the optimizer to return the OB_STATE_NOT_MATCH error.

  • Fixed an issue that the gv$SQL_PLAN_MONITOR view cannot properly display non-distributed plans.

  • Fixed an issue that an internal error is returned when the NVL() function is used in the CASE WHEN statement.

  • Fixed an issue that in Oracle mode, the value of the PARTITION KEY COUNT field in the ALL_PART_TABLES table is not displayed.

  • Fixed an issue that the tenant restore operation fails when the tenant is deleted.

  • Fixed an issue that in MySQL mode, the execution of the SET PASSWORD statement in stored procedures does not take effect.

  • Fixed an issue that the creation of views in PL fails in MySQL mode.

  • Fixed an issue that the redo_transport_option parameter of the standby cluster does not take effect.

  • Fixed an issue that the observer process unexpectedly exits during the conversion from the INT and STRING data types to the DATATIME, DATE, and TIME data types.

  • Fixed an issue that the observer process unexpectedly exits during the process of setting the PARALLEL_MAX_SERVERS variable.

  • Fixed an issue that in Oracle mode, the use of TRIGGER causes the SQL EXECUTOR module to have memory leaks.

  • Fixed an issue that Error 4019 is returned when you create a tenant after a large number of tenants are deleted.

  • Fixed an issue that the observer process unexpectedly exits during the process of setting the clog_disk_usage_limit_percentage and clog_disk_utilization_threshold parameters.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP7

Version information

  • Release date: September 18, 2021

  • Version: V2.2.77 BP7

  • RPM version: oceanbase-2.2.77-20210923214552

Enhanced features

  • The eviction mechanism of SQL execution plans for partitioned tables is optimized.

  • Secure Sockets Layer (SSL) communication encryption is supported by ob_admin.

  • The LOAD DATA REPLACE syntax is supported in Oracle mode.

  • The user logon and logoff statistics are collected.

  • The ORDER BY expression is supported in MySQL mode.

  • Automatic load balancing for partitions in a STOP SERVER/ZONE operation is optimized.

  • The routing of temporary tables is optimized.

Bug fixes

  • Fixed an issue that the creation of a tenant fails if the _enanble_easy_keepalive parameter is set to true.

  • Fixed an issue that the substr(c1,x,1)='a' query cannot hit the plan cache.

  • Fixed an issue that the logical restore fails because the rowkey does not meet the length requirements.

  • Fixed an issue that the accumulation of clogs causes the OBServer node to restart, which results in excessive memory consumption by the sys tenant.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP6

Version information

  • Release date: August 25, 2021

  • Version: V2.2.77 BP6

  • RPM version: oceanbase-2.2.77-20210825181323

Bug fixes

  • Fixed an issue that the backup set is marked as Deleted after the secondary backup fails.

  • Fixed an issue that in a scenario where a tenant restore operation is performed, if an existing tenant has the same name as the tenant to be recovered, the existing tenant is dropped.

  • Fixed an issue that in a parallel execution (PX), if a long timeout is set for a tenant by default, the operation of session termination takes a long time to respond.

  • Fixed an issue that the observer process may fail to start with a small probability after clog compression is enabled.

  • Fixed an issue that deadlocks are possible when SECURITY AUDIT is enabled in high concurrency scenarios.

  • Fixed an issue that the observer process unexpectedly exits in Oracle mode because of the execution of the SELECT FETCH UNION SELECT FETCH syntax.

  • Fixed an issue that the observer process unexpectedly exits when the memory request fails during the execution of a distributed plan.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP5

Version information

  • Release date: July 31, 2021

  • Version: V2.2.77 BP5

  • RPM version: oceanbase-2.2.77-20210730214129

Enhanced features

You can set the SQL_MODE parameter to NO_ZERO_IN_DATE in MySQL mode.

Compatibility changes

The following default actions of the SQL_MODE parameter are changed in MySQL mode:

  • In earlier versions, the STR_TO_DATE('202102', '%Y%m') function returns NULL.
  • In this version, the STR_TO_DATE('202102', '%Y%m') function returns 2021-01-31.
  • To roll back the default actions in earlier versions, manually set the sql_mode parameter. For example, set sql_mode = concat(@@sql_mode, ',NO_ZERO_IN_DATE').

Bug fixes

  • Fixed an issue that the observer process unexpectedly exits when an excessive number of columns are operated by the TRIGGER.

  • Fixed an issue that the query on the generated column in conjunction with the ORDER BY LIMIT action generates an incorrect plan.

  • Fixed an issue that incorrect results are generated because no deep copy is performed during a BATCH NESTED LOOP JOIN operation.

  • Fixed an issue that the observer process unexpectedly exits because no deep copy that allocates the memory is performed when the PL engine executes dynamic SQL statements.

  • Fixed an issue that the observer process unexpectedly exits because like Number is used as a filter condition.

  • Fixed an issue that the observer process unexpectedly exits when the redo log module prints logs.

  • Fixed an issue that an error is returned when the SHOW PROCEDURE STATUS statement is executed after the execution of the DROP USER statement.

  • Fixed an issue that the plan_type field of the sql_audit parameter displays incorrect plan type.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP4

Version information

  • Release date: July 13, 2021

  • Version: V2.2.77 BP4

  • RPM version: oceanbase-2.2.77-20210712224820

Enhanced features

  • The MAKETIME() function is supported in MySQL mode.

  • The UTC_DATE(), UTC_TIME(), and GET_FORMAT() functions are supported in MySQL mode.

Bug fixes

  • Fixed an issue that XA transactions in the Active status cannot be rolled back.

  • Fixed an issue that in Oracle mode, if the index column contains the CHAR data type and values that are less than or equal to 0, the index column cannot be queried.

  • Fixed an issue that the execution of the ANTI-, SEMI-, and OUTER-JOIN statements with an OR join condition generates incorrect data.

  • Fixed an issue that the observer process unexpectedly exits because of an OSS SDK bug during the physical backup to the Alibaba Cloud OSS bucket.

  • Fixed an issue that the observer process unexpectedly exits sometimes because of queries on the gv$sysstat view.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP3

Version information

  • Release date: June 18, 2021

  • Version: V2.2.77 BP3

  • RPM version: oceanbase-2.2.77-20210618130343

Enhanced features

  • The LOG(), LN(), PI(), RADIANS(), ATAN(), ASIN(), ACOS(), and COT() functions are supported in MySQL mode.

  • The MONTHNAME() function is supported in MySQL mode.

  • The LAST_DAY() function is supported in MySQL mode.

  • The QUARTER() function is supported in MySQL mode.

  • The BIT_LENGTH() function is supported in MySQL mode.

Bug fixes

  • Fixed an issue that the observer process unexpectedly exits during the packet return process of a query because of network exceptions.

  • Fixed an issue that the parallel execution framework has memory leaks.

  • Fixed an issue that the observer process unexpectedly exits during the process of obtaining the partition location because of concurrent memory requests.

  • Fixed an issue that the observer process unexpectedly exits during the eviction of the plan cache because of the access to a null pointer.

  • Fixed an issue that the observer process unexpectedly exits because of stack overflow, which is caused by a large number of static SQL statements in the anonymous block when prepared statement is disabled.

  • Fixed an issue that the execution of the SELF ANTI JOIN statement results in an incorrect estimation of the number of rows because of SQL rewriting.

  • Fixed an issue that the OB_ARCHIVE_TEMP_MEMORY module has memory leaks during log archiving.

  • Fixed an issue that the PL statement cannot hit the plan cache.

  • Fixed an issue that the OBServer node retains the session after the client is disconnected.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP2

Version information

  • Release date: June 4, 2021

  • Version: V2.2.77 BP2

  • RPM version: oceanbase-2.2.77-20210604113922

Enhanced features

  • In MySQL mode, using escape characters such as single quotation marks (' ') in a LIKE statement is supported.

  • You can explicitly disable the enforced routing of a transaction after it is complete by setting the tenant-level parameter ob_proxy_readonly_transaction_routing_policy. This way, all SQL statements in the transaction are forwarded to the same OBServer node.

  • The memory size that can be utilized by sql_audit of an OceanBase Database tenant is increased.

  • The timeout wait for asynchronous I/O is optimized.

Bug fixes

  • Fixed an issue that the RootServer node of the standby cluster occasionally exits unexpectedly.

  • Fixed an issue that the parameter that specifies the maximum memory available for sql_audit does not take effect.

  • Fixed an issue that when the GBK character set is used, two consecutive queries that use Chinese characters return incorrect filed name even if the data is correct.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77 BP1

Version information

  • Release date: May 27, 2021.

  • Version: V2.2.77 BP1

  • RPM version: oceanbase-2.2.77-20210526202046

Enhanced features

You can specify the maximum memory usage of partitions in a transaction by setting the tenant-level parameter _tenant_max_trx_size.

Bug fixes

  • Fixed an issue that the observer process unexpectedly exits when the memory is insufficient and the memory request fails.

  • Fixed an issue that the plan cache has memory leaks.

  • Fixed an issue that the Nested Loop Join operator may cause the observer process to unexpectedly exit in the TABLE ACCESS BY INDEX PRIMARY KEY operation.

  • Fixed an issue that when foreign keys exist, the Semi-Join rewrite generates incorrect results.

  • Fixed an issue that the observer process unexpectedly exits when an intermediate result set is released.

  • Fixed an issue that in Oracle mode, the WIDTH_BUCKET() function is incompatible with Oracle when min_value is less than expression.

  • Fixed an issue that in Oracle mode, the RPAD() function is incompatible with Oracle.

Upgrade and limitations

  • The primary and standby clusters can be upgraded only in maximum performance mode. If a cluster is in maximum protection mode or maximum availability mode, you must switch the cluster to maximum performance mode before you can upgrade the cluster.

  • PL debugging is supported only for x86 platforms. We recommend that you do not use this feature on an ARM platform.

V2.2.77

Version information

  • Release date: May 8, 2021

  • Version: V2.2.77

  • RPM version: oceanbase-2.2.77-20210508211731

Overview

OceanBase Database V2.2.X is a generally available series that provides products of higher availability, compatibility, and security for customers to batch launch multiple projects.

Enhanced features

  • Primary and standby clusters are enhanced.

  • Physical backup and restore are supported.

  • The encryption of an individual log-only replica at the zone level is supported.

  • Template-based and non-template-based subpartitioned tables are supported.

  • Drop and Truncate operations on partitioned tables are supported.

Bug fixes

  • Fixed an issue that an error is returned for the aligned read of the 4 KB clog offset.

  • Fixed an issue that an error is returned during the type derivation of an expression that contains NULL.

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