System variable summary|V4.3.5| docs|Distributed Database

Variable	Description
validate_password_check_user_name	Specifies whether the user password can be the same as the username.
validate_password_length	The minimum length of the user password.
validate_password_mixed_case_count	The minimum number of uppercase and lowercase letters that a user password must contain.
validate_password_number_count	The minimum number of digits that a user password must contain.
validate_password_policy	The password check strategy.
validate_password_special_char_count	The minimum number of special characters that a user password must contain.
ob_tcp_invited_nodes	The IP address allowlist of a tenant. The value can contain percent signs (%), underscores (_), and IP addresses. Multiple IP addresses are separated with commas (,). IP list matching, mask matching, and fuzzy matching are supported.
default_password_lifetime	The permitted password lifetime.
block_encryption_mode	The encryption algorithm used in the `AES_ENCRYPT()` and `AES_DECRYPT()` functions.
sql_safe_updates	Specifies whether to enable the safe update mode of MySQL. The mode is disabled by default.
super_read_only	Controls the read and write permissions of the database. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
pid_file	Queries the pathname of the file where the server writes its process ID.
port	Sets the port number for the server to listen for TCP/IP connections when deploying on OBServer nodes.
socket	Queries the name of the `Socket` file for local client connections.

Variable	Description
version_comment	The version information of the OBServer node.
version	The version number of the OBServer node.
ob_last_schema_version	The latest schema version used in the session.
ob_proxy_global_variables_version	The latest version information of global variables returned by the OBServer node to OceanBase Database Proxy (ODP).
ob_enable_transmission_checksum	Specifies whether to perform checksum comparison on data packets between ODP and the OBServer node. The setting takes effect immediately.
ob_compatibility_control	The compatible MySQL version in the case of a product behavior conflict. Valid values are `MYSQL5.7` and `MYSQL8.0`.
ob_compatibility_version	The compatible OceanBase Database version in the case of normal product behavioral changes.
ob_security_version	The compatible OceanBase Database version in the case of security-related product behavioral changes. You can specify the compatible version when you create a tenant. It cannot be modified after the tenant is created.
old_alter_table	Specifies whether to enable the `ALTER TABLE` syntax and operation method of an earlier version. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
debug	The debug option. The default value is `d:t:i:o,/tmp/mysqld.trace`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
ob_global_debug_sync	The synchronization point during debugging. Unlike `debug_sync`, this variable takes effect on all sessions.

Variable	Description
lower_case_table_names	Specifies whether object names are case-sensitive for storage and comparison.

Variable	Description
query_cache_size	The size of memory allocated for caching query results, which also indicates the size of memory not in use.
query_cache_type	The query cache type.
ob_query_timeout	The query timeout period.
is_result_accurate	Specifies whether the query result is correct when a query carries a `topk` hint.
net_buffer_length	The SQL query size acceptable to the OBServer node.
read_only	Specifies whether the tenant is in read-only mode.
ob_read_consistency	The read consistency level.
ob_max_read_stale_time	The maximum latency threshold, in μs, for weak-consistency read queries.
net_read_timeout	The number of seconds to wait for more data of the connection before aborting the read.
net_write_timeout	The number of seconds to wait for a block to be written to a connection before aborting the write.
ob_enable_index_direct_select	Specifies whether to enable direct queries of index tables.
ob_enable_aggregation_pushdown	Specifies whether to enable aggregation pushdown.
ob_enable_jit	Specifies whether to enable the just-in-time (JIT) execution engine.
sql_throttle_network	The request queuing time. If the request queuing time is greater than or equal to the specified value, the query is not executed.
parallel_servers_target	The queuing conditions for large queries on each server.
cte_max_recursion_depth	The maximum recursion depth of common table expressions (CTEs). The server aborts any operation that exceeds this CTE value.
regexp_stack_limit	The maximum memory available to the internal stack for regular expression matching operations.
regexp_time_limit	The time limit on regular expression matching operations.
long_query_time	Sets the threshold for slow queries.

Variable	Description
event_scheduler	Specifies whether the event scheduler is enabled and running on the server.

Variable	Description
ob_create_table_strict_mode	Specifies whether to enable the strict mode for table creation.
ob_default_replica_num	The default number of table replicas in each cluster.
master_info_repository	Specifies whether the replica records metadata to an InnoDB table in the `mysql` system database or as a file in the data directory. The default value is `FILE`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
replication_optimize_for_static_plugin_config	Specifies whether to enable shared locks to improve the performance of semi-synchronous replication. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
replication_sender_observe_commit_only	Specifies whether to limit callbacks to improve the performance of semi-synchronous replication. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_slave_enabled	Specifies whether to enable semi-synchronous replication on the replica. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_slave_trace_level	The debug trace level of semi-synchronous replication on the replica. The default value `32` indicates the net wait level. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_stop_slave_timeout	The number of seconds that the `STOP SLAVE` statement waits before it times out. The default value is `31536000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_checkpoint_group	The maximum number of transactions that can be processed in multi-threaded replication before a checkpoint operation is called to update the replication status. The default value is `512`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_checkpoint_period	The maximum number of milliseconds allowed to pass before a checkpoint operation is called to update the status of multi-threaded replication. The default value is `300`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_compressed_protocol	Specifies whether to use compression of the source or replica protocol when both the source and the replica support compression. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_exec_mode	Specifies how a replication thread responds to conflicts and errors during replication. The value `IDEMPOTENT` indicates to suppress duplicate-key and no-key-found errors. The value `STRICT` indicates not to suppress duplicate-key and no-key-found errors. The default value is `STRICT`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_max_allowed_packet	The maximum packet size for the replication SQL and I/O threads, in bytes. The default value is `1073741824`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_net_timeout	The number of seconds to wait for more data or a heartbeat signal from the source before the replica considers that the connection is broken, aborts the read, and tries to reconnect. The default value is `60`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_parallel_type	The type of replication transactions to be executed in parallel when multi-threaded replication is enabled. The default value is `DATABASE`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_parallel_workers	The number of threads for executing replication transactions in parallel. The default value `0` indicates to disable parallel execution of replication transactions. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_pending_jobs_size_max	The maximum size (in bytes) of worker queues storing events that have not yet been applied during multi-threaded replication. The default value is `16777216`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_preserve_commit_order	For multi-threaded replication, controls whether transactions are committed in the order they appear in the relay log. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
slave_rows_search_algorithms	The algorithms used to search for rows in the replica. The default value is `TABLE_SCAN,INDEX_SCAN`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
slave_sql_verify_checksum	Specifies whether the replication SQL thread uses checksums read from the relay log to verify data. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not cause errors nor have any effect.
slave_transaction_retries	Specifies the number of times the replication SQL thread automatically retries a transaction if it fails due to a deadlock or if the transaction execution time exceeds the value specified by the `innodb_lock_wait_timeout` variable. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
slave_type_conversions	Controls the type conversion mode on replicas when using row-based replication. Its default value is empty, which means type conversion between the source and the replica is disabled. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
sql_slave_skip_counter	The number of events from the source that the replica must skip. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
skip_slave_start	Specifies whether the replica server skips starting replication threads when the server starts. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
slave_load_tmpdir	The name of the directory where the replica creates temporary files. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
slave_skip_errors	The errors to skip during replication. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
sync_master_info	The effect of this variable on replicas depends on whether the replica's `master_info_repository` is set to FILE or TABLE. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not cause errors nor have any effect.
init_slave	This variable is similar to `init_connect` and is used to specify a string executed by the slave server each time the replication SQL thread starts. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not cause errors nor have any effect.
log_slow_slave_statements	Determines whether slow SQL executed by the replication thread is recorded in the slow query log if the replica server has slow query logging enabled. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not cause errors nor have any effect.
report_host	The hostname or IP address reported to the source during replica registration. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
report_password	The password for the replication user account reported to the source during replica registration. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
report_port	The TCP/IP port number used to connect to the replica, reported to the source during replica registration. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
report_user	The username of the account reported to the source during replica registration. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log	The name of the relay log. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log_basename	The name and full path of the relay log. Its default value is `/usr/local/mysql/data/obrd-relay-bin`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log_index	The name of the relay log index file. Its default value is `/usr/local/mysql/data/obrd-relay-bin.index`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log_info_file	The name of the file that records information about the relay log. Its default value is `relay-log.info`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log_recovery	If this variable is enabled, it allows automatic recovery of the relay log to be enabled immediately after the replica server starts. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
relay_log_space_limit	The maximum capacity available for all relay logs, in bytes. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.

Variable	Description
rpl_semi_sync_master_enabled	Specifies whether to enable semi-synchronous replication on the source. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_master_timeout	The number of milliseconds that the source waits after a commit for an acknowledgment from the replica. The default value is `10000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_master_trace_level	The debug trace level of semi-synchronous replication on the source. The default value `32` indicates the net wait level. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_master_wait_for_slave_count	The number of replica acknowledgments that the source must receive per transaction before proceeding. The default value is `1`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_master_wait_no_slave	Specifies whether the source waits for the timeout period specified by the `rpl_semi_sync_master_timeout` variable to expire, even if the replica count drops to a value less than the number of replicas specified by the `rpl_semi_sync_master_wait_for_slave_count` variable. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rpl_semi_sync_master_wait_point	The point at which a semi-synchronous source waits for acknowledgment of transaction receipt from the replica before returning the status to the client that committed the transaction. The default value is `AFTER_SYNC`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
recyclebin	Specifies whether to enable the recycle bin.
ob_enable_truncate_flashback	Specifies whether to enable flashback for truncated tables.

Variable	Description
ob_enable_plan_cache	Specifies whether to enable the plan cache.
ob_plan_cache_percentage	The percentage of tenant memory that can be occupied by the plan cache.
ob_plan_cache_evict_high_percentage	The percentage of the absolute value of the maximum memory usage to trigger plan cache eviction.
ob_plan_cache_evict_low_percentage	The percentage of the absolute value of the maximum memory usage to stop plan cache eviction.
ob_bnl_join_cache_size	The volume of the cached data that triggers a batch nested loop join.
stored_program_cache	The number of stored procedures and functions that can be cached. The default value is `256`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
table_definition_cache	The number of memory spaces for caching table definitions. The default value is `-1`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
table_open_cache_instances	Sets the number of open table cache instances. Its default value is `16`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.

Variable	Description
interactive_timeout	The number of seconds that the server waits for an interactive idle connection to become active before closing it.
wait_timeout	The number of seconds that the server waits for a non-interactive idle connection to become active before closing it.
group_concat_max_len	The maximum length of the result of the `GROUP_CONCAT()` function.

Variable	Description
innodb_change_buffering_debug	The debug level for InnoDB change buffering. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_compress_debug	The debug level for the adjustment and control of compression. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_disable_resize_buffer_pool_debug	Specifies whether to enable resizing of the InnoDB buffer pool. The default value is `1`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_fil_make_page_dirty_debug	Dirties the specified page during InnoDB debugging. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_limit_optimistic_insert_debug	The number of records per B-tree page. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_merge_threshold_set_all_debug	The page-full percentage of index pages. The default value is `50`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_saved_page_number_debug	The page number to save during InnoDB debugging. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_trx_purge_view_update_only_debug	The debug level for updating the purge view only during transaction purging. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_trx_rseg_n_slots_debug	The number of slots in the transaction rollback segment. Each slot stores transaction rollback information. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_stats_persistent	Specifies whether to persist InnoDB index statistics to the disk.
innodb_force_recovery	The crash recovery mode for recovering damaged data of the InnoDB storage engine. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_replication_delay	The replication thread delay in milliseconds on the replication server when the concurrency specified by `innodb_thread_concurrency` is reached. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_large_prefix	Specifies whether to allow index key prefixes longer than 767 bytes (up to 3,072 bytes) for InnoDB tables that use the `DYNAMIC` or `COMPRESSED` row format. The default value is `ON`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_sort_buffer_size	The buffer size for sorting operations. The default value is `1048576`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
default_tmp_storage_engine	The default storage engine for temporary tables. The default value is `InnoDB`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_tmpdir	The directory for storing InnoDB temporary files. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
mecab_rc_file	The path of the MeCab configuration file. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_temp_data_file_path	The path of the InnoDB temporary data file. The default value `ibtmp1:12M:autoextend` indicates that InnoDB uses a temporary data file named `ibtmp1` with an initial size of 12 MB and the file will automatically extend to store additional temporary data. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_data_file_path	The storage path and file name of the InnoDB data file. The default value `ibdata1:12M:autoextend` indicates that InnoDB uses a data file named `ibdata1` with an initial size of 12 MB and the file will automatically extend to store additional data. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_data_home_dir	The root directory of the InnoDB data file. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_read_only	Determines whether to start InnoDB in read-only mode. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.
innodb_rollback_on_timeout	Specifies whether to abort and roll back the entire transaction when a timeout occurs. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.
innodb_api_disable_rowlock	Determines whether to disable row locks during DML operations executed by InnoDB memcached. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.
innodb_autoinc_lock_mode	Specifies the lock mode used for generating auto-increment values. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.
low_priority_updates	Determines whether to control the priority of INSERT, UPDATE, DELETE, and REPLACE statements. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
max_error_count	Sets the maximum number of errors, warnings, and notices that the server can store in the diagnostic context. Its default value is `64`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
max_insert_delayed_threads	Specifies the maximum number of threads that can execute INSERT DELAYED statements. Its default value is `20`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried and set, but the setting operation will not take effect and will not report an error.
innodb_monitor_disable	This variable acts as a switch to control which metric counters are disabled. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_monitor_enable	This variable acts as a switch to control which metric counters are enabled. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_monitor_reset	This variable acts as a switch to control which metric counters are reset to 0. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_monitor_reset_all	This variable acts as a switch to control which metric counters have all values (maximum, minimum, etc.) reset to 0. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_old_blocks_pct	Specifies the approximate percentage of the old data block sublist in the InnoDB buffer pool. Its default value is `37`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_old_blocks_time	Specifies how long a block inserted into the old sublist must stay after its first access before it can be moved to the new sublist, in milliseconds. Its default value is `1000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_purge_batch_size	Specifies the number of undo log pages to parse and process from the history list at once. Its default value is `300`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_purge_rseg_truncate_frequency	Controls the frequency of purging rollback segments, i.e., how often the system releases a rollback segment after being called. Its default value is `128`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_random_read_ahead	Uses enabled random read-ahead technology to optimize InnoDB I/O. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_read_ahead_threshold	Controls the linear read-ahead behavior of the InnoDB storage engine. Its default value is `56`, which means InnoDB must sequentially read at least 56 pages from a segment to initiate asynchronous reads for the next segment. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_rollback_segments	Specifies the number of rollback segments for transactions generating Undo records. Its default value is `128`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_spin_wait_delay	The interval for each spin lock wait. Its default value is `6`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_status_output	Enables or disables periodic output of the standard InnoDB monitor. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_status_output_locks	Enables or disables InnoDB lock monitoring. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_sync_spin_loops	The number of times a thread waits before being suspended when an InnoDB mutex is released. Its default value is `30`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
internal_tmp_disk_storage_engine	Specifies the storage engine for internal temporary tables on disk. Its default value is `INNODB`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_fast_shutdown	The shutdown mode of the InnoDB engine. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_io_capacity	The approximate number of IOPS that InnoDB can perform per second for background tasks. Its default value is `200`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_io_capacity_max	The maximum number of IOPS that can be performed per second for background tasks in emergency situations. Its default value is `2000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_thread_concurrency	The maximum number of threads allowed internally by InnoDB. Its default value is `0`, which means unlimited. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_thread_sleep_delay	The time, in microseconds, that InnoDB threads sleep before being added to the InnoDB wait queue. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it does not produce an error and has no effect.
innodb_adaptive_hash_index_parts	Specifies the number of partitions for the adaptive hash index search system. Its default value is `8`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_numa_interleave	Indicates whether to enable the NUMA interleave memory policy for allocating buffer pool memory. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_open_files	Specifies the maximum number of files that can be opened at one time. Its default value is `2000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_page_cleaners	The number of threads for flushing dirty pages from the buffer pool. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_purge_threads	The number of background threads used for purge operations. Its default value is `4`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_read_io_threads	The number of I/O threads for performing read operations. Its default value is `4`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_sync_array_size	Specifies the size of the mutex/lock wait array. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_use_native_aio	Indicates whether to use the Linux asynchronous I/O subsystem. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_write_io_threads	The number of I/O threads for performing write operations. Its default value is `4`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_api_enable_binlog	Indicates whether to allow the use of the InnoDB memcached plugin with the MySQL binlog. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_locks_unsafe_for_binlog	This variable affects how InnoDB uses gap locking for searches and index scans. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_log_buffer_size	Specifies the size of the InnoDB transaction log buffer in bytes. Its default value is `16777216`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_log_files_in_group	The number of log files in the log group. Its default value is `2`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_log_file_size	The size of each log file in the log group in bytes. Its default value is `50331648`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_log_group_home_dir	Specifies the directory path for the InnoDB Redo logs. Its default value is `./`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_undo_directory	Specifies the directory for undo tablespaces created by InnoDB. Its default value is `./`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
innodb_undo_tablespaces	Specifies the number of undo tablespaces available for use by InnoDB. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.

Variable	Description
ob_capability_flag	The capabilities that the OBServer node can provide. It is used to inform ODP of the features supported and features not supported by the OBServer node during capability negotiation between the OBServer node and ODP.
ob_compatibility_mode	The compatibility mode of a tenant.
ob_route_policy	Sets the routing policy for selecting data replicas within OBServer nodes.
performance_schema	Declares to the client whether performance queries are supported. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 8.0, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
resource_manager_plan	Activates a resource management plan. The CPU quota for limiting the user activities in a resource group varies based on the resource management plan.
license	The license type.
ob_proxy_partition_hit	Specifies whether to enable ODP to send the data requested by SQL statements to the OBServer node where the primary partition of the data is located.
ob_org_cluster_id	The `CLUSTER_ID` of the OceanBase cluster.
server_uuid	The UUID of the OBServer node.
default_storage_engine	The default storage engine of the OBServer node.
slave_allow_batching	Specifies whether to enable batch updates on replication threads. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
datadir	The local disk directory for data storage.
plugin_dir	The directory for storing plug-in DLL files.
secure_file_priv	The directory that can be accessed for file import or export.
ob_enable_hash_group_by	Specifies whether to enable `HASH GROUP BY`.

Variable	Description
delay_key_write	Specifies whether to delay key writing for MyISAM tables. The default value is `ON`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
key_buffer_size	The key buffer size of the MyISAM storage engine. The default value is `8388608`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
key_cache_age_threshold	The threshold to trigger the demotion of buffers from the hot sublist of a key cache to the warm sublist. A smaller value causes quicker demotion. The default value is `300`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
key_cache_block_size	The size in bytes of a block in the MyISAM key cache. The default value is `1024`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
key_cache_division_limit	The division point for the MyISAM key cache. The default value is `100`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
max_seeks_for_key	The maximum number of key seeks allowed in a MyISAM query. The default value is `18446744073709551615`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
skip_external_locking	Determines whether to disable the external locking mechanism for MyISAM tables. Its default value is `ON`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.

Variable	Description
max_tmp_tables	The maximum number of temporary tables supported in a user session. The default value is `32`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
ob_sql_work_area_percentage	The maximum percentage of tenant memory for SQL statement execution.
ob_sql_audit_percentage	The maximum percentage of the SQL audit memory to the total memory of the current tenant.
ob_reserved_meta_memory_percentage	The percentage of reserved memory of a tenant. The reserved memory mainly stores metadata-related structure information.
ob_temp_tablespace_size_percentage	The temporary tablespace size threshold in percentage for a tenant disk.

Variable	Description
ndb_allow_copying_alter_table	Indicates whether `ALTER TABLE` statements and other DDL statements are allowed to use copying operations on tables. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_autoincrement_prefetch_sz	Specifies the number of prefetch values for auto-increment, affecting performance and concurrency access for auto-increment columns. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_blob_read_batch_bytes	Configures the size of batch reads for BLOB data in NDB Cluster, in bytes. Its default value is `65536`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_blob_write_batch_bytes	Configures the size of batch writes for BLOB data in NDB Cluster, in bytes. Its default value is `65536`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_cache_check_time	Specifies the interval in milliseconds for checking if the cache needs refreshing on each NDB node. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_clear_apply_status	Specifies whether to clear the apply status. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_data_node_neighbour	Defines the neighbor relationship of data nodes. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_default_column_format	Defines the default column format for tables, whether stored in fixed-length format or variable-length format. Its default value is `FIXED`, meaning stored in fixed-length format. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_deferred_constraints	Controls whether constraint checks on tables are deferred. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_distribution	Specifies the default distribution method for NDB tables, whether partitioned by hash key or linear hash. Its default value is `KEYHASH`, meaning partitioned by hash key. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_eventbuffer_free_percent	Specifies the percentage of free space in the NDB Cluster event buffer. Its default value is `20`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_eventbuffer_max_alloc	Specifies the maximum allocatable memory size for the event buffer, in bytes. Its default value is `0`, meaning no limit. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_extra_logging	Used to log specified information from the NDB storage engine in the MySQL error log. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_force_send	Whether to force sending the cache to NDB immediately without waiting for other threads. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_fully_replicated	Determines whether new tables are fully replicated. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_index_stat_enable	Whether to use the NDB index statistics collection feature. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_index_stat_option	Specifies the options for generating NDB index statistics. Its default value is `loop_checkon=1000ms,loop_idle=1000ms,loop_busy=100ms,update_batch=1,read_batch=4,idle_batch=32,check_batch=32,check_delay=1m,delete_batch=8,clean_delay=0,error_batch=4,error_delay=1m,evict_batch=8,evict_delay=1m,cache_limit=32M,cache_lowpct=90`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_join_pushdown	Controls whether the join pushdown optimization feature in the storage engine is enabled. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_binlog_index	Controls whether to insert the mapping of epochs to positions in the binlog into the ndb_binlog_index table. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_empty_epochs	Controls whether unchanged epoch transactions are written to the binlog. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_empty_update	Controls whether unchanged update transactions are written to the binlog. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_exclusive_reads	Determines whether to use exclusive locks to log primary key reads. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_update_as_write	Controls whether updates on the source are written to the binlog as updates (`OFF`) or writes (`ON`). Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_update_minimal	Controls the logging behavior of NDB Cluster. When set to `ON`, NDB Cluster logs only minimal information about update operations; when set to `OFF`, it logs changes to the entire row. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_updated_only	Controls whether Mysqld writes only updated rows or the full row to the binlog when writing updates. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_optimization_delay	Specifies the wait time in microseconds between each group of rows when using the OPTIMIZE TABLE statement on NDB tables. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_read_backup	Specifies whether data can be read from any fragment replica of any NDB table created afterwards. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_recv_thread_activation_threshold	Specifies the activation threshold for receive threads. Its default value is `8`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_recv_thread_cpu_mask	Specifies the CPU mask for running receive threads. Its default value is an empty string. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_report_thresh_binlog_epoch_slip	Specifies the maximum allowed slip size before reporting a binlog timestamp slip. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_report_thresh_binlog_mem_usage	Specifies the threshold percentage of remaining available memory for the binlog before sending a report. When the remaining available memory falls below this value, the system sends a report. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_row_checksum	Specifies the checksum value for table rows. A value of `1` means that a checksum is calculated and stored for each row; a value of `0` means no checksum is performed on table row data. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_show_foreign_key_mock_tables	Controls whether to display mock tables for foreign key dependencies. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_slave_conflict_role	Specifies the role of this node in a circular replication (master-master) setup. Its default value is `NONE`, indicating undefined or unconfigured. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_table_no_logging	Controls the logging behavior of NDB tables. When set to `ON`, all tables created or altered using the NDB storage engine are in a no-log state. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_table_temporary	Specifies the behavior of temporary tables when using the NDB storage engine. When set to `ON`, it causes NDB tables not to be written to disk. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_use_exact_count	Specifies whether to force NDB to use record counting during the query plan for `SELECT count(*)` to speed up such queries. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_use_transactions	Controls whether NDB transaction support is enabled. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_max_bytes	Used only for testing and debugging. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_max_rows	Used only for testing and debugging. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_offline	Controls whether the `ndbinfo` database is set to offline status. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_show_hidden	Controls whether to display the underlying internal tables of the `ndbinfo` database in the MySQL client. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_data_pointer_size	Sets the default pointer size, in bytes, for created MyISAM tables when the `MAX_ROWS` option is not specified. Its default value is `6`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_max_sort_file_size	Specifies the maximum size of temporary files allowed when recreating MyISAM indexes during `REPAIR TABLE`, `ALTER TABLE`, or `LOAD DATA`. Its default value is `9223372036853720064` bytes. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_repair_threads	Specifies the number of concurrent threads used when repairing MyISAM tables. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_sort_buffer_size	Specifies the buffer size allocated for sorting MyISAM indexes during `REPAIR TABLE` or when creating indexes using `CREATE INDEX` (or `ALTER TABLE`). Its default value is `8388608` bytes. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_stats_method	Specifies how the server calculates statistics for the distribution of index values in MyISAM tables, particularly for NULL values. Its default value is `nulls_unequal`, which treats NULL values as ordinary values, similar to other values. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_use_mmap	Determines whether to use memory mapping for reading and writing MyISAM tables. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
server_id_bits	Specifies the least significant number of bits in a 32-bit `server_id` that are used to actually identify the server. Its default value is `32`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.

Variable	Description
innodb_ft_enable_diag_print	Specifies whether to enable the debug output of InnoDB full-text indexes. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_ft_num_word_optimize	The minimum number of words to process during an `OPTIMIZE TABLE` operation. The default value is `2000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_ft_result_cache_limit	The maximum size of the result cache for InnoDB full-text indexes, in bytes. The default value is `2000000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_ft_server_stopword_table	The server stopword list for InnoDB full-text indexes. The default value is `NULL`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_optimize_fulltext_only	Specifies whether to change the way the `OPTIMIZE TABLE` statement operates on InnoDB tables containing full-text indexes. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_ft_cache_size	The size of the cache for InnoDB full-text indexes, in bytes. The default value is `8000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_ft_sort_pll_degree	The number of parallel threads for full-text index sorting. The default value is `2`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
innodb_ft_total_cache_size	The total size of the cache for InnoDB full-text indexes, in bytes. The default value is `640000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
ft_stopword_file	The path of the file from which the list of stopwords is read. The default value is `built-in`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.

Variable	Description
runtime_filter_type	The runtime filter type at the tenant level.
runtime_filter_wait_time_ms	The maximum waiting duration for runtime filters.
runtime_filter_max_in_num	The number of distinct values (NDV) in the filter condition specified by the runtime filter of the IN type.
runtime_bloom_filter_max_size	The maximum memory usage in bytes allowed for the runtime filter of the BLOOM_FILTER type.

Variable	Description
avoid_temporal_upgrade	Specifies whether to upgrade temporal data such as datetime data. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
time_zone	The session time zone of the current tenant. The value can be an offset, such as `'+08:00'`, or a geographical location, such as `Asia/Shanghai`.
timestamp	The timestamp in seconds. This variable affects the result of `SELECT NOW(6)`.
system_time_zone	The system time zone of the server.
error_on_overlap_time	Specifies whether to report an error in case of an ambiguous boundary datetime value, a case in which it is not clear whether the datetime is in standard or daylight saving time.
nls_language	The default language of prompt messages, date, month, and the default values of `nls_sort` and `nls_date_language`.
nls_territory	The current territory, which is used in combination with `nls_language`.
nls_date_language	The default date language.
nls_calendar	The calendar system used by the database.
ob_timestamp_service	The timestamp service.

Variable	Description
autocommit	Specifies whether to automatically commit transactions.
tx_isolation	The isolation level of transactions.
ob_proxy_set_trx_executed	Specifies whether to send `START TRANSACTION Syntax` to the OBServer node through ODP.
ob_early_lock_release	Specifies whether to enable the early lock release (ELR) feature for transactions. Note This variable has been deprecated since V2.2.30. The ELR feature is now controlled by the tenant-level parameter `enable_early_lock_release`.
ob_trx_idle_timeout	The idle timeout period of a transaction. A timeout error occurs if the execution interval between two consecutive statements in the transaction exceeds the value of this variable.
transaction_isolation	The isolation level of transactions.
transaction_read_only	Specifies whether to enable just read-only transactions.
ob_trx_lock_timeout	The lock wait timeout period for transactions.
tx_read_only	Specifies whether the transaction is read-only.
ob_trx_timeout	The transaction timeout period.
ob_trace_info	The trace information to be transparently transferred, which can be stored in redo logs.
gtid_executed	Stores the set of all transactions that have been committed and the GTIDs set by statements. Its default value is `NULL`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.
gtid_owned	Stores the list of all GTIDs currently in use and the IDs of the threads owning them. Its default value is `NULL`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. It can be queried but cannot be set.

Variable	Description
ob_enable_sql_audit	Specifies whether to enable SQL audit for the current tenant.

Variable	Description
nls_length_semantics	The length semantics of the CHAR and VARCHAR2 data types.
nls_nchar_conv_excp	Specifies whether to report an error when data is lost during the conversion between NCHAR/NVARCHAR2 and CHAR/VARCHAR2.
nls_numeric_characters	The decimal and thousands separators used in a string during the conversion between a number and a string.
nls_currency	The local currency symbol for the `L` number format element.
nls_iso_currency	The local currency symbol for the `C` number format element.
nls_dual_currency	The local currency symbol for the `U` number format element.
nls_date_format	The format of converting a date to a string and the format of implicitly converting a string to a date.
nls_timestamp_format	The format to use when you convert a timestamp or LTZ timestamp to a string, or when you implicitly convert a string to a timestamp or LTZ timestamp.
nls_timestamp_tz_format	The format to use when you convert a timestamp or TZ timestamp to a string, or when you implicitly convert a string to a timestamp or TZ timestamp.
explicit_defaults_for_timestamp	Specifies whether to enable non-standard behaviors for processing default values and NULL values in TIMESTAMP columns.
log_row_value_options	Specifies whether LOB fields use partial updates.
ob_default_lob_inrow_threshold	The default INROW storage threshold for LOB fields in a table.

Variable	Description
connect_timeout	The connection timeout period.
ob_pl_block_timeout	The maximum timeout period for Procedural Language (PL) execution.
cursor_sharing	Specifies whether to parameterize an SQL statement when processing it.
have_profiling	Indicates whether statement profiling is supported. The default value is `NO`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
profiling	Specifies whether to enable the statement profiling feature. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
profiling_history_size	The number of statements whose profiling information is stored. The default value is `15`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
innodb_strict_mode	The check mode for SQL statements with specific syntax.
max_connections	The maximum number of connections for a tenant.
sql_mode	The SQL mode. Actions such as insert vary greatly with the SQL mode.
sql_quote_show_create	Specifies whether to quote identifiers for the `SHOW CREATE TABLE` and `SHOW CREATE DATABASE` statements.
ob_enable_rich_error_msg	Specifies whether to display information such as `svr_ip`, `time`, and `trace_id` when an error occurs during SQL statement execution.
sql_throttle_current_priority	The throttling priority. Only requests of sessions whose `sql_throttle_current_priority` value is less than the `sql_throttle_priority` value are throttled.
sql_throttle_priority	The throttling priority.
sql_throttle_rt	The response time (RT).
max_allowed_packet	The maximum size of a network packet.
max_user_connections	The maximum number of connections that a single user can set up with the OBServer node. When the value is set to `0`, the number of connections is not limited.
max_sp_recursion_depth	The maximum recursion level of a specified stored procedure.
sql_select_limit	The maximum number of rows to be returned for a SELECT query.
max_connections	The maximum number of connections for a tenant.
ob_enable_blk_nestedloop_join	Specifies whether to enable Block Nested Loop (BNL) join.
parallel_max_servers	The maximum number of threads in the parallel execution (PX) thread pool on each server.
sql_transpiler	Controls whether to enable the SQL Transpiler feature. Note This variable is available starting with V4.3.5 BP5.

Variable	Description
binlog_row_image	Specifies whether to record full column logs.
ob_enable_show_trace	Specifies whether to enable trace logs.
ob_log_level	The level of session logs. If this variable is not specified, the system log level is used.
tracefile_identifier	The custom identifier that becomes part of the log so that a row iteration trace log can be identified with ease.
master_verify_checksum	Specifies whether to examine checksums for data verification. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
log_statements_unsafe_for_binlog	Determines whether error code 1592 information is logged in the error log. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
binlog_gtid_simple_recovery	Controls how the server iterates over binlog files during GTID search upon startup or restart. Its default value is `1`, meaning the values of `gtid_executed` and `gtid_purged` are calculated at startup based on the values of `previous_gtids_log_event` in the newest and oldest binlog files. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
log_bin_basename	The full pathname of the binlog files. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
log_bin_index	The name and path of the binlog index file. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.
log_slave_updates	Determines whether a replica server logs updates received from its master server's binlog into its own binlog. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but it cannot be set.

Variable	Description
preload_buffer_size	Specifies the buffer size in bytes used when preloading indexes. Its default value is `32768`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
read_buffer_size	Specifies the buffer size in bytes available for reading data. Its default value is `131072`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
read_rnd_buffer_size	Specifies the buffer size in bytes used when reading data from MyISAM tables, and also for multi-range read optimization for any storage engine. Its default value is `262144`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
sync_frm	Determines whether to sync InnoDB table metadata information to the `.frm` file on disk. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
keep_files_on_create	Controls whether the server retains existing files in the directory when creating MyISAM tables without specifying data or index file locations using the `DATA DIRECTORY` or `INDEX DIRECTORY` options. Its default value is `OFF`, meaning existing files are overwritten. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
max_heap_table_size	Specifies the maximum size in bytes that user-created memory tables are allowed to grow to. Its default value is `16777216`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
bulk_insert_buffer_size	Specifies the buffer size in bytes/thread used for bulk insert operations. Its default value is `8388608`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
general_log_file	Specifies the name of the general query log file. Its default format is `host_name.log`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
host_cache_size	Specifies the size of the host cache. Its default value is `279`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_error_verbosity	Defines the level of detail for errors, warnings, and notes written to the error log. Its default value is `3`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_output	Specifies the destination for the general query log and slow query log output. Its default value is `FILE`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_queries_not_using_indexes	Determines whether queries not using indexes are logged in the slow query log. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_slow_admin_statements	Specifies whether slow administrative statements like ALTER TABLE, ANALYZE TABLE, CHECK TABLE, CREATE INDEX, DROP INDEX, OPTIMIZE TABLE, and REPAIR TABLE are logged in the slow query log. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_syslog	Determines whether the error log is recorded in the system log. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_syslog_facility	The tool used for writing the error log output to the system log. Its default value is `daemon`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_syslog_include_pid	Specifies whether the service process ID is written to the system log in the error log output. Its default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_syslog_tag	Specifies the tag to add to the server identifier in the error log output written to the system log. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_throttle_queries_not_using_indexes	The maximum number of statements per minute written to the slow query log. Its default value is `0`, meaning no limit. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_timestamps	Controls the timezone of timestamps written to the error log, general log, and slow query log files. Its default value is `UTC`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
log_warnings	Specifies the level of additional warning messages recorded in the error log. Its default value is `2`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
max_delayed_threads	The maximum number of threads allowed to be created for processing INSERT DELAYED statements. Its default value is `20`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
offline_mode	Specifies whether the server is set to offline mode. Its default value is `0`, meaning it is not set to offline mode. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
require_secure_transport	Specifies whether connections between the client and server must use some form of secure transport. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
slow_launch_time	When the time taken to create a thread exceeds this value, the status variable Slow_launch_threads is incremented. The unit is seconds, and its default value is `2`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
sql_log_off	Enables (`OFF`) or disables (`ON`) the general query log recording for the current session. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
thread_cache_size	The maximum number of threads that can be contained in the thread cache. Its default value is `9`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
thread_pool_high_priority_connection	Controls whether the thread pool reserves idle threads for high-priority connections. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
thread_pool_max_unused_threads	The maximum number of unused threads allowed in the thread pool. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
thread_pool_prio_kickup_timer	The time required, in milliseconds, before a statement moves to the high-priority queue. Its default value is `1000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
thread_pool_stall_limit	The time, in units of 10 milliseconds, within which a statement must complete after starting execution. Its default value is `6`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
have_statement_timeout	Specifies whether the timeout feature for statement execution is enabled. Its default value is `ON`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
old	A compatibility variable used to address compatibility issues. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
version_tokens_session_number	An internally used variable with a default value of `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
back_log	The maximum number of pending connection requests that can be stored in the queue while the server is processing connection requests. Its default value is `80`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
basedir	The pathname of the installation root directory. Its default value is `/usr/local/mysql/`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
bind_address	The IP address to which the server binds when listening for TCP/IP client connections. Its default value is `*`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
core_file	Specifies whether the server should generate a core file upon exiting due to a fatal error. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
have_compress	Indicates whether the zlib compression library required for the COMPRESS() and UNCOMPRESS() functions is available. Its default value is `ON`, meaning it is available. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
ignore_db_dirs	A comma-separated list of names that are not considered as database directories in the data directory. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
init_file	Specifies a filename containing SQL statements that the server executes at startup. Its default value is `null`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
large_files_support	Indicates whether the server supports handling large files. Its default value is `1`, meaning support is enabled. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
large_pages	Specifies whether large page support is enabled. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
large_page_size	If large page support is enabled, this variable specifies the size of memory pages in bytes. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
locked_in_memory	Indicates whether the server is locked in memory. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
log_error	The output destination of the error log file. Its default value is `./obrd.16c.vd3-s2h6-n3.err`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
named_pipe	Indicates whether the server allows clients to connect using named pipes. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
named_pipe_full_access_group	Specifies which Windows user group has permission to connect using named pipes when supported. Its default value is `empty string`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
open_files_limit	The number of file descriptors available to the server. Its default value is `655360`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
shared_memory	Indicates whether the server allows clients to connect using shared memory. Its default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
shared_memory_base_name	Specifies the name of the shared memory used for shared memory connections. Its default value is `MYSQL`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
skip_name_resolve	Controls whether hostnames are resolved when checking client connections. Its default value is `OFF`, meaning hostnames need to be resolved. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
skip_networking	Controls whether the server allows TCP/IP connections. Its default value is `OFF`, meaning TCP/IP connections are disabled. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
thread_handling	The thread model the server uses to handle client connections. Its default value is `one-thread-per-connection`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
thread_pool_algorithm	Controls the algorithm used by the thread pool plugin. Its default value is `0`, indicating a conservative low concurrency algorithm. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
thread_pool_size	Sets the number of thread groups in the thread pool. Its default value is `16`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
thread_stack	The stack size for each thread. Its default value is `262144`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
tls_version	Specifies which protocols the server allows for encrypted connections. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.

Variable	Description
mysqlx_bind_address	Specifies the network address X Plugin listens for TCP/IP connections. Its default value is `*`, meaning it accepts TCP/IP connections from all server hosts. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_port	Specifies the network port X Plugin listens for TCP/IP connections. Its default value is `33060`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_port_open_timeout	Specifies the time X Plugin waits for the TCP/IP port to be idle, in seconds. Its default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_socket	Specifies the path of the Unix socket file used by X Plugin for connections. Its default value is `/tmp/mysqlx.sock`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_ca	Specifies the pathname of the SSL certificate authority (CA) file used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_capath	Specifies the directory path of the SSL certificate authority (CA) certificates used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_cert	Specifies the pathname of the SSL certificate file used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_cipher	Specifies the list of encryption algorithms used by X Plugin for SSL encryption. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_crl	Specifies the filename containing the certificate revocation list used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_crlpath	Specifies the directory path containing the certificate revocation list files used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
mysqlx_ssl_key	Specifies the pathname of the SSL certificate key file used by X Plugin. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.

Variable	Description
performance_schema_accounts_size	Specifies the number of rows in the `accounts` table. Its default value is `-1`, meaning it auto-scales. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_digests_size	Specifies the maximum number of rows in the `events_statements_summary_by_digest` table. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_stages_history_long_size	Specifies the number of rows in the `events_stages_history_long` table. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_stages_history_size	Specifies the number of rows per thread in the `events_stages_history` table. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_statements_history_long_size	Specifies the number of rows in the `events_statements_history_long` table. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_statements_history_size	Specifies the number of rows per thread in the `events_statements_history` table. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_transactions_history_long_size	Specifies the number of rows in the `events_transactions_history_long` table. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_transactions_history_size	Specifies the number of rows per thread in the `events_transactions_history` table. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_waits_history_long_size	Specifies the number of rows in the `events_waits_history_long` table. Its default value is `10000`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_events_waits_history_size	Specifies the number of rows per thread in the `events_waits_history` table. Its default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_hosts_size	Specifies the number of rows in the `hosts` table. Its default value is `-1`, meaning it auto-scales. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_cond_classes	Specifies the maximum number of condition collectors. Its default value is `80`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_cond_instances	Specifies the maximum number of condition objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_digest_length	Specifies the maximum length, in bytes, of a normalized SQL statement stored in the performance schema. The default value is `1024`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_file_classes	Specifies the maximum number of file collectors. The default value is `80`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_file_handles	Specifies the maximum number of file objects that can be opened. The default value is `32768`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_file_instances	Specifies the maximum number of file objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_index_stat	Specifies the maximum number of indexes for which statistics are maintained in the performance schema. The default value is `-1`, indicating automatic resizing. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_memory_classes	Specifies the maximum number of memory collectors. The default value is `320`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_metadata_locks	Specifies the maximum number of metadata lock collectors. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_mutex_classes	Specifies the maximum number of mutex collectors. The default value is `200`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_mutex_instances	Specifies the maximum number of mutex objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_prepared_statements_instances	Specifies the maximum number of rows in the `prepared_statements_instances` table. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_program_instances	Specifies the maximum number of stored programs for which statistics are maintained in the performance schema. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_rwlock_classes	Specifies the maximum number of rwlock collectors. The default value is `50`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_rwlock_instances	Specifies the maximum number of rwlock objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_socket_classes	Specifies the maximum number of socket collectors. The default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_socket_instances	Specifies the maximum number of socket objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_sql_text_length	Specifies the maximum length, in bytes, of SQL statements that can be stored in the `SQL_TEXT` column of statement event tables such as `events_statements_current`, `events_statements_history`, and `events_statements_history_long`. The default value is `1024`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_stage_classes	Specifies the maximum number of stage collectors. The default value is `150`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_statement_classes	Specifies the maximum number of statement collectors. The default value is `193`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_statement_stack	Specifies the maximum depth of nested stored program calls for which statistics are maintained in the performance schema. The default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_table_handles	Specifies the maximum number of table objects that can be opened. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_table_instances	Specifies the maximum number of table objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_table_lock_stat	Specifies the maximum number of tables for which lock statistics are maintained in the performance schema. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_thread_classes	Specifies the maximum number of thread collectors. The default value is `50`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_max_thread_instances	Specifies the maximum number of thread objects that can be collected. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_session_connect_attrs_size	The amount of preallocated memory, in bytes, reserved per thread for storing connection attribute key-value pairs. The default value is `512`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_setup_actors_size	Specifies the number of rows in the `setup_actors` table. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_setup_objects_size	Specifies the number of rows in the `setup_objects` table. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.
performance_schema_users_size	Specifies the number of rows in the `users` table. The default value is `-1`, indicating automatic scaling. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.

Variable	Description
metadata_locks_cache_size	The size of the metadata lock cache, in bytes. The default value is `1024`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
metadata_locks_hash_instances	The number metadata lock hashes. The default value is `8`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.

Variable	Description
foreign_key_checks	Specifies whether to enable FOREIGN KEY constraint check for DML or DDL statements.

Variable	Description
mview_refresh_dop	Controls the default refresh parallelism of materialized views.

Variable	Description
optimizer_use_sql_plan_baselines	Specifies whether the optimizer uses SQL plan baselines.
optimizer_capture_sql_plan_baselines	Specifies whether new plans can be automatically captured to the plan baseline.
parallel_degree_policy	The strategy based on which the optimizer selects the degree of parallelism (DOP).
parallel_degree_limit	The maximum DOP that the optimizer can select when the Auto DOP strategy is used.
parallel_min_scan_time_threshold	The minimum evaluation period for the parallel scan of base tables.
optimizer_dynamic_sampling	The level of dynamic sampling.
optimizer_features_enable	The version of the OceanBase Database optimizer that you want to enable.
ob_enable_transformation	Specifies whether to enable the rewrite feature of the SQL optimizer.
ob_table_access_policy	Controls the optimizer to prioritize a specific storage format when generating base table plans.

Variable	Description
auto_increment_increment	The auto-increment step size. It is used only for MySQL client login.
auto_increment_offset	The start value of an auto-increment column.
last_insert_id	The last inserted auto-increment value in the current session.
identity	The `identity` variable is synonymous with the `last_insert_id` variable and can be queried by using `select @@identity`.
sql_auto_is_null	Specifies whether to obtain the auto-increment column value of the last inserted row.
auto_increment_cache_size	The number of cached auto-increment values.
div_precision_increment	The number of digits by which to increase the scale of the result of a division operation based on the scale of the dividend. This variable is for compatibility with MySQL.

Variable	Description
character_set_client	The character set in which the statements are sent by the client.
character_set_connection	The character set to which the received statements are converted.
character_set_database	The character set of the default database.
character_set_results	The character set to which the server converts the result sets or error messages before sending them to the client.
character_set_server	The character set of the server.
character_set_system	The character set of the system.
collation_connection	The character set and collation for the connection.
collation_database	The default character set and collation of the database.
collation_server	The default character set and collation for the server.
character_set_filesystem	The character set of the file system.
sql_warnings	Specifies whether to generate an information string for single-row `INSERT` statements when warnings occur.
init_connect	The character string that the server executes for each connected client. The string consists of one or more SQL statements which are separated by semicolons (;).
nls_sort	The string value sorting rule.
nls_comp	The string value comparison rule.
nls_characterset	The default character set of the data types such as CHAR, VARCHAR2, and CLOB in the database.
nls_nchar_characterset	The default character set of the database, which is used for data types such as NCHAR, NVARCHAR2, and NCLOB.

Variable	Description
group_replication_allow_local_disjoint_gtids_join	Specifies whether to allow a server to join a group when the server has local transactions that are not present in the group. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_allow_local_lower_version_join	Specifies whether to allow a server to join a group when the server has a lower MySQL Server version than other members of the group. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_auto_increment_increment	The step size of auto-increment columns of members in a replication group. This variable ensures that values in auto-increment columns of members in a multi-primary group are ordered without overlapping. The default value is `7`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_bootstrap_group	Specifies whether to use the current server to bootstrap the group. You can set this variable only on one server and only when you start the group for the first time or restart the group. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_components_stop_timeout	The timeout period in seconds that group replication waits for each component when shutting down. The default value is `2`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_compression_threshold	The threshold in bytes to trigger compression of messages sent between group members. If the size of a message sent between group members exceeds the threshold, the message will be compressed. The default value is `1000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_enforce_update_everywhere_checks	Specifies whether to enable strict consistency checks for multi-primary updates everywhere. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_exit_state_action	Specifies how group replication behaves when a server instance leaves the group unintentionally. The default value is `READ_ONLY`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_flow_control_applier_threshold	The number of waiting transactions in the applier queue that trigger flow control. The default value is `25000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_flow_control_certifier_threshold	The number of waiting transactions in the certifier queue that trigger flow control. The default value is `25000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_flow_control_mode	The flow control mode. The default value is `QUOTA`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_force_members	The list of member addresses, in the `host1:port1,host2:port2` format. This variable is used to forcibly create a new group. The members not included in the list do not receive new view messages and their write operations are blocked. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_group_name	The name of the replication group to which the current server belongs. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_group_seeds	The list of seed member addresses, in the `host1:port1,host2:port2` format. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_gtid_assignment_block_size	The number of consecutive global transaction IDs (GTIDs) reserved for each member. The default value is `1000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_ip_whitelist	The IP addresses or host names of the hosts allowed to connect to the group. These addresses are called allowlisted addresses. The default value is `AUTOMATIC`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_local_address	The network address that a replication group member provides for connections from other group members. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_member_weight	The percentage weight assigned to a member to influence the chance of the member being elected as the new primary node upon failover. This variable applies only to single-primary groups. When the primary node leaves a single-primary group, a member with a higher weight value is preferentially elected as the new primary node. The default value is `50`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_poll_spin_loops	The number of times the group communication thread waits for the communication engine mutex to be released before the thread waits for more incoming network messages. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_complete_at	The strategy for handling cached transactions after state transfer during distributed recovery. The default value is `TRANSACTIONS_APPLIED`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_reconnect_interval	The interval in seconds between reconnection attempts when no donor is found in the group. If a server finds no donor in a group for distributed recovery when the server attempts to join the group, the server will make reconnection attempts at the interval specified by this variable to search for an available donor. The default value is `60`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_retry_count	The number of reconnection attempts allowed to search for an available donor. If a server finds no donor in a group for distributed recovery when the server attempts to join the group, the server will make reconnection attempts for the times specified by this variable to search for an available donor. The default value is `10`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_ca	The path to a file that contains a list of trusted SSL certificate authorities for distributed recovery connections. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_capath	The path to a directory that contains certificates issued by trusted SSL certificate authorities for distributed recovery connections. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_cert	The name of the SSL certificate file to use for establishing a secure connection for distributed recovery. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_cipher	The list of ciphers supported for SSL encryption. The supported ciphers vary with the version of the SSL library used for compiling the MySQL server. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_crl	The path to a file that contains certificate revocation lists. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_crlpath	The path to a directory that contains certificate revocation lists. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_key	The name of the SSL key file to use for establishing a secure connection for distributed recovery. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_verify_server_cert	Specifies whether to verify the common name of the server in the donor certificate during distributed recovery. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_use_ssl	Specifies whether to use SSL for distributed recovery connections between replication group members. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_single_primary_mode	Specifies whether to run group replication in single-primary mode and automatically select a server to handle read/write workloads. The value `ON` indicates that only one member is selected as the primary node to perform read/write operations and other members are auxiliary nodes. The value `OFF` indicates to disable the single-primary mode and enable the multi-primary mode. In multi-primary mode, all group members are primary nodes that support read/write operations. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_ssl_mode	The security state of SSL connections between replication group members. The default value is `DISABLED`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_start_on_boot	Specifies whether to start group replication when the server starts. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_transaction_size_limit	The maximum size in bytes of transactions that the replication group can accept. The default value is `150000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_unreachable_majority_timeout	The number of seconds to wait before a group member that suffers a network partition and therefore cannot connect to the majority leaves the group. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
ob_last_schema_version	The latest schema version used in the session.
old_alter_table	Specifies whether to enable the `ALTER TABLE` syntax and operation method of an earlier version. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
debug	The debug option. The default value is `d:t:i:o,/tmp/mysqld.trace`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
is_result_accurate	Specifies whether the query result is correct when a query carries a `topk` hint.
long_query_time	Sets the threshold for slow queries.

Variable	Description
master_info_repository	Specifies whether the replica records metadata to an InnoDB table in the `mysql` system database or as a file in the data directory. The default value is `FILE`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

Variable	Description
table_definition_cache	The number of memory spaces for caching table definitions. The default value is `-1`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
table_open_cache_instances	The number of open table cache instances. The default value is `16`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query it, but cannot set it.

Variable	Description
ob_capability_flag	The capabilities that the OBServer node can provide. It is used to inform ODP of the features supported and features not supported by the OBServer node during capability negotiation between the OBServer node and ODP.
ob_proxy_partition_hit	Specifies whether to enable ODP to send the data requested by SQL statements to the OBServer node where the primary partition of the data is located.
ob_org_cluster_id	The `CLUSTER_ID` of the OceanBase cluster.

Variable	Description
ndb_allow_copying_alter_table	Determines whether `ALTER TABLE` statements and other DDL statements can use copying operations on tables. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_autoincrement_prefetch_sz	Specifies the prefetch quantity for auto-increment values, which can affect the performance and concurrent access capability of auto-increment columns. The default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_blob_read_batch_bytes	Configures the batch read size for BLOB data in the NDB Cluster, in bytes. The default value is `65536`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_blob_write_batch_bytes	Configures the batch write size for BLOB data in the NDB Cluster, in bytes. The default value is `65536`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_deferred_constraints	Controls whether constraint checks on tables are deferred. The default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_fully_replicated	Determines whether new tables are fully replicated. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_index_stat_enable	Determines whether to use the NDB index statistics collection feature. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_index_stat_option	Specifies options for generating NDB index statistics. The default value is `loop_checkon=1000ms,loop_idle=1000ms,loop_busy=100ms,update_batch=1,read_batch=4,idle_batch=32,check_batch=32,check_delay=1m,delete_batch=8,clean_delay=0,error_batch=4,error_delay=1m,evict_batch=8,evict_delay=1m,cache_limit=32M,cache_lowpct=90`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_join_pushdown	Controls whether to enable join pushdown optimization in the storage engine. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_binlog_index	Controls whether to insert the mapping of epochs to binlog positions into the ndb_binlog_index table. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_log_exclusive_reads	Determines whether to use Exclusive locks for recording primary key reads. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_row_checksum	Specifies the checksum for table rows. A value of `1` means checksums are calculated and stored for each row; a value of `0` means no checksum detection is performed. The default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_use_exact_count	Specifies whether to force NDB to use record counting to accelerate `SELECT count(*)` queries during query planning. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndb_use_transactions	Controls whether to enable NDB transaction support. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_max_bytes	Used only for testing and debugging. The default value is `0`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_max_rows	Used only for testing and debugging. The default value is `10`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
ndbinfo_show_hidden	Determines whether to display underlying internal tables of the `ndbinfo` database in the MySQL client. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_repair_threads	Specifies the number of concurrent threads for repairing MyISAM tables. The default value is `1`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_sort_buffer_size	Specifies the buffer size allocated for sorting MyISAM indexes during REPAIR TABLE or for creating indexes with CREATE INDEX (or ALTER TABLE), in bytes. The default value is `8388608`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_stats_method	Specifies how the server calculates NULL values when collecting statistics on index value distribution for MyISAM tables. The default value is `nulls_unequal`, meaning NULL values are treated as ordinary values, just like other values. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
myisam_use_mmap	Determines whether to use memory mapping for reading and writing MyISAM tables. The default value is `OFF`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.

Variable	Description
have_profiling	Indicates whether statement profiling is supported. The default value is `NO`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query this variable but cannot set it.
profiling	Specifies whether to enable the statement profiling feature. The default value is `0`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
profiling_history_size	The number of statements whose profiling information is stored. The default value is `15`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
enable_sql_plan_monitor	Determines whether the SQL of the current session is recorded in the SQL plan monitor.
sql_transpiler	Controls whether to enable the SQL Transpiler feature. Note This variable is available starting with V4.3.5 BP5.

Variable	Description
ob_enable_show_trace	Specifies whether to enable trace logs.
tracefile_identifier	The custom identifier that becomes part of the log so that a row iteration trace log can be identified with ease.

Variable	Description
pseudo_slave_mode	Specifies whether to switch the server to the pseudo slave mode. The default value is `OFF`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
pseudo_thread_id	The ID of the session thread. The default value is `2147483647`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
rbr_exec_mode	The execution mode of the session thread. Valid values are `IDEMPOTENT` and `STRICT`. The default value is `STRICT`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
preload_buffer_size	Specifies the buffer size for preloading indexes, in bytes. The default value is `32768`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
read_buffer_size	Specifies the buffer size available for reading data, in bytes. The default value is `131072`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
read_rnd_buffer_size	Specifies the buffer size for reading data from MyISAM tables, and for multi-range read optimization for any storage engine, in bytes. The default value is `262144`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
keep_files_on_create	Controls whether the server retains existing files in the directory when creating MyISAM tables if the `DATA DIRECTORY` or `INDEX DIRECTORY` options are not used to specify locations for data or index files. The default value is `OFF`, meaning existing files are overwritten. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
max_heap_table_size	Specifies the maximum size to which user-created memory tables are allowed to grow, in bytes. The default value is `16777216`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.
bulk_insert_buffer_size	Specifies the buffer size for bulk insert operations, in bytes per thread. The default value is `8388608`. Note This variable is only for compatibility with MySQL 5.7. The related functionality is not supported. You can query and set it, but setting it will not produce an error nor have any effect.

Variable	Description
timestamp	The timestamp in seconds. This variable affects the result of `SELECT NOW(6)`.
nls_language	The default language of prompt messages, date, month, and the default values of `nls_sort` and `nls_date_language`.

Variable	Description
ob_proxy_set_trx_executed	Specifies whether to send `START TRANSACTION Syntax` to the OBServer node through ODP.
ob_trace_info	The trace information to be transparently transferred, which can be stored in redo logs.

Variable	Description
ob_hnsw_ef_search	Sets the number of neighbor points searched in each layer of the graph during vector index queries using the HNSW algorithm.
ob_ivf_nprobes	Sets the number of nearest cluster centers to search during a vector index query. This variable affects the performance and recall rate of IVF-type queries: the larger the value, the higher the recall rate, but the search time will also increase.

Variable	Description
ob_table_access_policy	Controls the optimizer to prioritize a specific storage format when generating base table plans.

Variable	Description
last_insert_id	The last inserted auto-increment value in the current session.

Variable	Description
group_replication_force_members	The list of member addresses, in the `host1:port1,host2:port2` format. This variable is used to forcibly create a new group. The members not included in the list do not receive new view messages and their write operations are blocked. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_group_name	The name of the replication group to which the current server belongs. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_gtid_assignment_block_size	The number of consecutive GTIDs reserved for each member. The default value is `1000000`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_ip_whitelist	The IP addresses or host names of the hosts allowed to connect to the group. These addresses are called allowlisted addresses. The default value is `AUTOMATIC`. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_local_address	The network address that a replication group member provides for connections from other group members. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_ca	The path to a file that contains a list of trusted SSL certificate authorities for distributed recovery connections. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_capath	The path to a directory that contains certificates issued by trusted SSL certificate authorities for distributed recovery connections. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_cert	The name of the SSL certificate file to use for establishing a secure connection for distributed recovery. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_cipher	The list of ciphers supported for SSL encryption. The supported ciphers vary with the version of the SSL library used for compiling the MySQL server. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_crl	The path to a file that contains certificate revocation lists. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_crlpath	The path to a directory that contains certificate revocation lists. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.
group_replication_recovery_ssl_key	The name of the SSL key file to use for establishing a secure connection for distributed recovery. By default, this variable is left empty. Note This variable is used only for compatibility with MySQL 5.7, but its functionality is not implemented. You can query and set this variable, but the setting does not take effect even though the system does not return an error.

System variable summary

Global variables

Security variables

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Version variables

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Debugging variables

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Case sensitivity variables

Read/Write and query variables

Scheduler variables

Replica variables

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Replication source variables

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Recycle bin variables

Cache variables

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Function variables

InnoDB storage engine variables

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