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
        Overview
        BIT_AND
        BIT_COMPLEMENT
        BIT_OR
        BIT_XOR
        CAST_FROM_BINARY_DOUBLE
        CAST_FROM_BINARY_FLOAT
        CAST_FROM_BINARY_INTEGER
        CAST_FROM_NUMBER
        CAST_TO_BINARY_DOUBLE
        CAST_TO_BINARY_FLOAT
        CAST_TO_BINARY_INTEGER
        CAST_TO_NUMBER
        CAST_TO_NVARCHAR2
        CAST_TO_RAW
        CAST_TO_VARCHAR2
        COMPARE
        CONCAT
        COPIES
        LENGTH
        REVERSE
        SUBSTR
    - PL label security package
      - Overview of label security PL packages
      - SA_SYSDBA policy management package
        Overview
        SA_SYSDBA.ALTER_POLICY
        SA_SYSDBA.CREATE_POLICY
        SA_SYSDBA.DROP_POLICY
      - SA_COMPONENTS label component package
        Overview
        SA_COMPONENTS.ALTER_LEVEL
        SA_COMPONENTS.CREATE_LEVEL
        SA_COMPONENTS.DROP_LEVEL
      - SA_LABEL_ADMIN label management package
        Overview
        SA_LABEL_ADMIN.ALTER_LABEL
        SA_LABEL_ADMIN.CREATE_LABEL
        SA_LABEL_ADMIN.DROP_LABEL
      - SA_POLICY_ADMIN policy management package
        Overview
        SA_POLICY_ADMIN.APPLY_TABLE_POLICY
        SA_POLICY_ADMIN.DISABLE_TABLE_POLICY
        SA_POLICY_ADMIN.ENABLE_TABLE_POLICY
        SA_POLICY_ADMIN.REMOVE_TABLE_POLICY
      - SA_USER_ADMIN user label management package
        Overview
        SA_USER_ADMIN.SET_LEVELS
      - SA_SESSION session management package
        Overview
        SA_SESSION.LABEL
        SA_SESSION.RESTORE_DEFAULT_LABELS
        SA_SESSION.ROW_LABEL
        SA_SESSION.SET_LABEL
        SA_SESSION.SET_ROW_LABEL
    - Reserved PL keywords
- SQL practices and recommendations
  - Limits on writing SQL statements
  - SQL writing conventions
    - SELECT statements
    - DML statements
    - Multi-table join statements
    - Table scan
    - Transactions
    - Cache
    - Hint
    - Others
  - SQL statement examples
    - Implicit data type conversion
    - JOIN tables
    - Weak consistency read
    - Pagination queries
- Common errors and solutions
  - MySQL
    - About error codes
    - Database connection error
    - Timeout errors
      - Idle session timeout
      - Transaction timeout errors
    - User errors
      - Locked user
      - Incorrect user password
    - Table errors
      - Table already exists
      - Table does not exist
      - Invalid use of NULL value
    - Constraint errors
      - Unique key conflict
      - Foreign key conflicts
    - SQL errors
      - Data inconsistency
  - Oracle
    - Overview
    - Database connection error
    - Timeout errors
      - Idle session timeout
      - Transaction timeout errors
    - User errors
      - Locked user
      - Incorrect user password
    - Object errors
      - Object already exists
      - Object does not exist
    - Constraint errors
      - Unique key conflict
      - Foreign key conflicts
    - SQL errors
      - Data type inconsistency
Architecture
- Architecture of OceanBase Database
- Development of OceanBase Database
- Multi-tenant architecture
  - Overview
  - Compatibility modes
  - System tenants
  - User tenants
  - Tenant and resource management
    - Manage tenant resources
    - Multi-tenant resource isolation
    - Balance resource units
- Database objects
  - Oracle mode
    - Introduction to database objects
      - Overview
      - Database object types
      - Database object storage
      - Dependencies between database objects
    - Tables
      - Overview
      - Data types
        Overview
        Character data types
        Numeric data types
        Date and time data types
        ROWID data types
        LOB data types
        Format models
        Overview
        Number format models
        Datetime format models
      - Integrity constraints
      - Table storage
      - Table compression
      - Partitioned tables
      - Table groups
      - Tables with and without a primary key
      - Temporary tables
    - Indexes
      - Overview of indexes
      - Local and global indexes
      - Unique and non-unique indexes
      - Index usage
      - Index storage
    - Partitions
      - Overview
      - Partition key
      - Partition types
      - Partitioned indexes
    - Views
      - Overview
      - Data manipulation in views
      - Data access from views
      - Updatable views
    - Other objects
      - Sequences
      - Synonyms
    - System views
      - Dictionary views
      - Dynamic performance views
    - Data integrity
      - Overview
      - Types of integrity constraints
        Overview
        NOT NULL constraints
        UNIQUE KEY constraints
        PRIMARY KEY constraints
        Foreign key constraints
        CHECK constraints
      - Use of integrity constraints
  - MySQL mode
    - Introduction to database objects
      - Overview
      - Database object types
      - Database object storage
      - Dependencies between database objects
    - Tables
      - Overview
      - Data types
        Overview
        Numeric data types
        Date and time data types
        Character data types
        LOB data types
      - Integrity constraints
      - Table storage
      - Table compression
      - Partitioned tables
      - Table groups
      - Tables with and without a primary key
    - Indexes
      - Overview
      - Local and global indexes
      - Unique and non-unique indexes
      - Index usage
      - Index storage
    - Partitions
      - Overview
      - Partition key
      - Partitioning strategies
      - Partitioned indexes
    - Views
      - Overview
      - Data manipulation in views
      - Data access from views
      - Updatable views
    - System views
      - Dictionary views
      - Performance views
    - Data integrity
      - Overview
      - Types of integrity constraints
        Overview
        NOT NULL integrity constraints
        UNIQUE KEY constraints
        PRIMARY KEY constraints
        Foreign key constraints
      - Use of integrity constraints
- Distributed database objects
  - Overview
  - Cluster architecture
  - Data partitions and replicas
    - Overview
    - Partition replica types
      - Overview
      - Full-featured replicas
      - Log-only replicas
      - Encrypted voting replicas
      - Read-only replicas
    - Multi-replica consensus protocols
    - Data balancing
      - Partition replica balancing
        Automatic load balancing
        Table groups
      - Leader balancing
        Automatic load balancing
        Primary zone
  - Dynamic scaling
    - Cluster scaling
    - Tenant resource scaling
      - Overview
      - Horizontal scaling of tenant resources
      - Vertical scaling of tenant resources
      - Cross-zone management of tenant resources
- Data link
  - Overview
  - ODP
    - Overview
    - SQL statement routing
    - Connection management
    - Configuration management
    - Logs and monitoring
  - Database drivers
    - Overview
    - OBCI
    - OceanBase Connector/J
    - OceanBase Connector/C
- User interfaces and query languages
  - SQL
    - SQL introduction
      - SQL overview
      - SQL data access
      - SQL standards
    - SQL statement
      - Overview
      - DDL
      - DML
      - DCL
    - Execution process of SQL queries
    - SQL execution plan
    - Distributed execution plan
      - Distributed execution and parallel query
      - Generate distributed execution plans
      - Run and disable a parallel query
      - Manage distributed execution plans
      - Parameter tuning for a parallel query
  - PL
    - PL concepts
      - Oracle mode
        Subprograms
        Stored procedures
        Functions
        Triggers
        Packages
      - MySQL mode
        Subprograms
        Stored procedure
        Functions
        Triggers
    - PL subprogram execution mechanism
  - Client programming languages
- Transaction management
  - Transactions
    - Overview of transactions
    - Transaction structure
    - Statement-level atomicity
    - GTS
    - Transaction control
      - Overview
      - Active transactions
      - Savepoints
      - Transaction control statements
        MySQL transaction control
        Oracle transaction control
    - Redo logs
    - Local transactions
    - Distributed transactions
      - Overview
      - Two-phase commit
    - XA transactions
  - Transaction concurrency and consistency
    - Overview
    - Multi-version read consistency
    - Concurrency control
      - Overview
      - Lock mechanism
    - Transaction isolation levels
      - Overview
      - Oracle mode
      - MySQL mode
    - Weak consistency read
- Storage architecture
  - Overview
  - Data storage
    - Overview
    - MemTables
    - SSTables
    - Compression and encoding
  - Minor compaction and major compaction
    - Overview
    - Minor compactions
    - Major compactions
  - Multi-level caching
  - Query processing
  - Data integrity
    - Detect silent data corruption
- Data reliability and HA
  - HA architecture
    - Overview
    - ODP HA
    - Leader election in distributed systems
    - Multi-replica log synchronization
    - Paxos protocol
    - Automatic handling of node faults
    - GTS HA
  - Deployment solutions for disaster recovery
  - Primary/standby cluster
    - Overview
    - Typical scenarios
    - Protection modes
    - Log transfer service
    - Role switching
    - Read service of standby clusters
    - Benefits
  - Data protection
    - Overview
    - Flashback queries
    - Restore points
    - Recycle bin
  - Backup and restore
    - Overview
    - Backup metadata for restoration
    - Backup architecture
    - Restoration architecture
- Database security
  - Overview
  - Identity authentication
  - Access control
  - Data transmission encryption
  - Data storage encryption
  - Monitoring and alerts
  - Security audit
- OBServer architecture
  - Structure of the OBServer installation directory
  - Configuration files
  - OBServer thread model
    - Threads
    - Worker threads
    - Background threads
  - Logs
  - Memory management
    - Overview
    - Memory-related parameters
    - Memory-related internal tables
    - Memory usage logs
    - Diagnose memory errors
- Appendix: Basic concepts of OceanBase Database
Releases
- V3.2
  - OceanBase Database Enterprise Edition V3.2.4
  - OceanBase Database Enterprise Edition V3.2.3
  - OceanBase Database Enterprise Edition V3.2.2
  - OceanBase Database Enterprise Edition V3.2.1
  - OceanBase Database Enterprise Edition V3.2.0
- V3.1
  - OceanBase Database Enterprise Edition V3.1.2
  - OceanBase Database Enterprise Edition V3.1.1
- V2.2
  - OceanBase Database Enterprise Edition V2.2.77

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LEFT

Last Updated：2023-10-24 09:23:03 Updated

LEFT(str,len)

Purpose

You can call this function to return the leftmost len characters of the str string. If str or len is NULL, NULL is returned.

This function is multi-byte safe.

Examples

obclient> SELECT LEFT('oceanbase', 5);
+----------------------+
 LEFT('oceanbase', 5) 
+----------------------+
 ocean                
+----------------------+
1 row in set (0.00 sec)

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