Server Status Variables

Most status variables are described on this page, but some are described elsewhere:

Use the statement to view status variables. This information also can be obtained using the command, or by querying the tables.

Issuing a will reset many status variables to zero.

List of Server Status Variables

`Aborted_clients`

Description: Number of aborted client connections. This can be due to the client not calling mysql_close() before exiting, the client sleeping without issuing a request to the server for more seconds than specified by or , or by the client program ending in the midst of transferring data. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Aborted_connects`

Description: Number of failed server connection attempts. This can be due to a client using an incorrect password, a client not having privileges to connect to a database, a connection packet not containing the correct information, or if it takes more than seconds to get a connect packet. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Aborted_connects_preauth`

Description: Number of connection attempts that were aborted prior to authentication (regardless of whether or not an error occured).
Scope: Global
Data Type: numeric

`Access_denied_errors`

Description: Number of access denied errors. For details on when this is incremented, see .
Scope: Global
Data Type: numeric

`Acl_column_grants`

Description: Number of column permissions granted (rows in the ).
Scope: Global
Data Type: numeric

`Acl_database_grants`

Description: Number of database permissions granted (rows in the ).
Scope: Global
Data Type: numeric

`Acl_function_grants`

Description: Number of function permissions granted (rows in the with a routine type of FUNCTION).
Scope: Global
Data Type: numeric

`Acl_package_body_grants`

Description:
Scope: Global
Data Type: numeric

`Acl_package_spec_grants`

Description:
Scope: Global
Data Type: numeric

`Acl_procedure_grants`

Description: Number of procedure permissions granted (rows in the with a routine type of PROCEDURE).
Scope: Global
Data Type: numeric

`Acl_proxy_users`

Description: Number of proxy permissions granted (rows in the ).
Scope: Global
Data Type: numeric

`Acl_role_grants`

Description: Number of role permissions granted (rows in the ).
Scope: Global
Data Type: numeric

`Acl_roles`

Description: Number of roles (rows in the where is_role='Y').
Scope: Global
Data Type: numeric

`Acl_table_grants`

Description: Number of table permissions granted (rows in the ).
Scope: Global
Data Type: numeric

`Acl_users`

Description: Number of users (rows in the where is_role='N').
Scope: Global
Data Type: numeric

`Busy_time`

Description: Cumulative time in seconds of activity on connections. Part of . Requires the system variable to be set in order to be recorded.
Scope: Global
Data Type: numeric

`Bytes_received`

Description: Total bytes received from all clients.
Scope: Global
Data Type: numeric

`Bytes_sent`

Description: Total bytes sent to all clients.
Scope: Global, Session
Data Type: numeric

`Com_admin_commands`

Description: Number of admin commands executed. These include table dumps, change users, binary log dumps, shutdowns, pings and debugs.
Scope: Global, Session
Data Type: numeric

`Com_alter_db`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_db_upgrade`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_event`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_function`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_procedure`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_sequence`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_server`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_alter_tablespace`

Description: Number of commands executed (unsupported by MariaDB).
Scope: Global, Session
Data Type: numeric
Removed:

`Com_alter_user`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_analyze`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_assign_to_keycache`

Description: Number of assign to keycache commands executed.
Scope: Global, Session
Data Type: numeric

`Com_backup`

Description:
Scope: Global, Session
Data Type: numeric
Removed:

`Com_backup_lock`

Description:
Scope: Global, Session
Data Type: numeric
Removed:

`Com_backup_table`

Description: Removed in . In older versions, Com_backup_table contains the number of commands executed.
Scope: Global, Session
Data Type: numeric
Removed:

`Com_begin`

Description: Number of or statements executed.
Scope: Global, Session
Data Type: numeric

`Com_binlog`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_call_procedure`

Description: Number of procedure_name statements executed.
Scope: Global, Session
Data Type: numeric

`Com_change_db`

Description: Number of database_name commands executed.
Scope: Global, Session
Data Type: numeric

`Com_check`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_checksum`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_commit`

Description: Number of commands executed. Differs from , which counts internal commit statements.
Scope: Global, Session
Data Type: numeric

`Com_compound_sql`

Description: Number of sql statements.
Scope: Global, Session
Data Type: numeric

`Com_create_db`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_event`

Description: Number of commands executed. Differs from in that it is incremented when the CREATE EVENT is run, and not when the event executes.
Scope: Global, Session
Data Type: numeric

`Com_create_function`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_index`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_package`

Description:
Scope: Global, Session
Data Type: numeric

`Com_create_package_body`

Description:
Scope: Global, Session
Data Type: numeric

`Com_create_procedure`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_role`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_sequence`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_server`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_temporary_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_trigger`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_udf`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_user`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_create_view`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_dealloc_sql`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_delete`

Description: Number of commands executed. Differs from , which counts the number of times rows have been deleted from tables.
Scope: Global, Session
Data Type: numeric

`Com_delete_multi`

Description: Number of multi-table commands executed.
Scope: Global, Session
Data Type: numeric

`Com_do`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_db`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_event`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_function`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_index`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_package`

Description:
Scope: Global, Session
Data Type: numeric

`Com_drop_package_body`

Description:
Scope: Global, Session
Data Type: numeric

`Com_drop_procedure`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_role`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_sequence`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_server`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_temporary_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_trigger`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_user`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_drop_view`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_empty_query`

Description: Number of queries to the server that do not produce SQL queries. An SQL query simply returning no results does not increment Com_empty_query - see instead. An example of an empty query sent to the server is mariadb --comments -e '-- sql comment'
Scope: Global, Session
Data Type: numeric

`Com_execute_immediate`

Description: Number of statements executed.
Scope: Global, Session
Data Type: numeric

`Com_execute_sql`

Description: Number of statements executed.
Scope: Global, Session
Data Type: numeric

`Com_flush`

Description: Number of commands executed. This differs from , which also counts internal server flush requests.
Scope: Global, Session
Data Type: numeric

`Com_get_diagnostics`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_grant`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_grant_role`

Description: Number of role commands executed.
Scope: Global, Session
Data Type: numeric

`Com_ha_close`

Description: Number of table_name CLOSE commands executed.
Scope: Global, Session
Data Type: numeric

`Com_ha_open`

Description: Number of table_name OPEN commands executed.
Scope: Global, Session
Data Type: numeric

`Com_ha_read`

Description: Number of table_name READ commands executed.
Scope: Global, Session
Data Type: numeric

`Com_help`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_insert`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_insert_select`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_install_plugin`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_kill`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_load`

Description: Number of LOAD commands executed.
Scope: Global, Session
Data Type: numeric

`Com_load_master_data`

Description:
Scope: Global, Session
Data Type: numeric
Removed:

`Com_load_master_table`

Description:
Scope: Global, Session
Data Type: numeric
Removed:

`Com_multi`

Description:
Scope: Global, Session
Data Type: numeric

`Com_lock_tables`

Description: Number of [lock-tables|LOCK TABLES]] commands executed.
Scope: Global, Session
Data Type: numeric

`Com_optimize`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_preload_keys`

Description:
Scope: Global, Session
Data Type: numeric

`Com_prepare_sql`

Description: Number of statements executed.
Scope: Global, Session
Data Type: numeric

`Com_purge`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_purge_before_date`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_release_savepoint`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_rename_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_rename_user`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_repair`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_replace`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_replace_select`

Description: Number of ... commands executed.
Scope: Global, Session
Data Type: numeric

`Com_reset`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_resignal`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_restore_table`

Description: Removed in . In older versions, Com_restore_table contains the number of commands executed.
Scope: Global, Session
Data Type: numeric
Removed:

`Com_revoke`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_revoke_all`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_revoke_grant`

Description: Number of role commands executed.
Scope: Global, Session
Data Type: numeric

`Com_rollback`

Description: Number of commands executed. Differs from , which is the number of transaction rollback requests given to a storage engine.
Scope: Global, Session
Data Type: numeric

`Com_rollback_to_savepoint`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_savepoint`

Description: Number of commands executed. Differs from , which is the number of transaction savepoint creation requests.
Scope: Global, Session
Data Type: numeric

`Com_select`

Description: Number of commands executed. Also includes queries that make use of the .
Scope: Global, Session
Data Type: numeric

`Com_set_option`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_signal`

Description: Number of statements executed.
Scope: Global, Session
Data Type: numeric

`Com_show_authors`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_binlog_events`

Description: Number of statements executed.
Scope: Global, Session
Data Type: numeric

`Com_show_binlogs`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_charsets`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_client_statistics`

Description: Number of commands executed. Removed in when that statement was replaced by the generic .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_collations`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_column_types`

Description:
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_contributors`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_db`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_event`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_func`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_package`

Description:
Scope: Global, Session
Data Type: numeric

`Com_show_create_package_body`

Description:
Scope: Global, Session
Data Type: numeric

`Com_show_create_proc`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_table`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_trigger`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_create_user`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_databases`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_engine_logs`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_engine_mutex`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_engine_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_events`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_errors`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_explain`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_fields`

Description: Number of or SHOW FIELDS commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_function_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_generic`

Description: Number of generic commands executed, such as and
Scope: Global, Session
Data Type: numeric

`Com_show_grants`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_keys`

Description: Number of or SHOW KEYS commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_index_statistics`

Description: Number of commands executed. Removed in when that statement was replaced by the generic .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_open_tables`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_package_status`

Description:
Scope: Global, Session
Data Type: numeric

`Com_show_package_body_status`

Description:
Scope: Global, Session
Data Type: numeric

`Com_show_plugins`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_privileges`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_procedure_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_processlist`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_profile`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_profiles`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_relaylog_events`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numericst

`Com_show_storage_engines`

Description: Number of - or SHOW ENGINES - commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_table_statistics`

Description: Number of commands executed. Removed in when that statement was replaced by the generic .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_table_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_tables`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_triggers`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_user_statistics`

Description: Number of commands executed. Removed in when that statement was replaced by the generic .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_variable`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_warnings`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_shutdown`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_stmt_close`

Description: Number of closed ().
Scope: Global, Session
Data Type: numeric

`Com_stmt_execute`

Description: Number of .
Scope: Global, Session
Data Type: numeric

`Com_stmt_fetch`

Description: Number of fetched.
Scope: Global, Session
Data Type: numeric

`Com_stmt_prepare`

Description: Number of .
Scope: Global, Session
Data Type: numeric

`Com_stmt_reprepare`

Description: Number of reprepared.
Scope: Global, Session
Data Type: numeric

`Com_stmt_reset`

Description: Number of where the data of a prepared statement which was accumulated in chunks by sending long data has been reset.
Scope: Global, Session
Data Type: numeric

`Com_stmt_send_long_data`

Description: Number of where the parameter data has been sent in chunks (long data).
Scope: Global, Session
Data Type: numeric

`Com_truncate`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_uninstall_plugin`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_unlock_tables`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_update`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric

`Com_update_multi`

Description: Number of multi-table commands executed.
Scope: Global, Session
Data Type: numeric

`Com_xa_commit`

Description: Number of XA statements committed.
Scope: Global, Session
Data Type: numeric

`Com_xa_end`

Description: Number of XA statements ended.
Scope: Global, Session
Data Type: numeric

`Com_xa_prepare`

Description: Number of XA statements prepared.
Scope: Global, Session
Data Type: numeric

`Com_xa_recover`

Description: Number of XA RECOVER statements executed.
Scope: Global, Session
Data Type: numeric

`Com_xa_rollback`

Description: Number of XA statements rolled back.
Scope: Global, Session
Data Type: numeric

`Com_xa_start`

Description: Number of XA statements started.
Scope: Global, Session
Data Type: numeric

`Compression`

Description: Whether client-server traffic is compressed.
Scope: Session
Data Type: boolean

`Connection_errors_accept`

Description: Number of errors that occurred during calls to accept() on the listening port. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connection_errors_internal`

Description: Number of refused connections due to internal server errors, for example out of memory errors, or failed thread starts. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connection_errors_max_connections`

Description: Number of refused connections due to the limit being reached. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connection_errors_peer_address`

Description: Number of errors while searching for the connecting client IP address. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connection_errors_select`

Description: Number of errors during calls to select() or poll() on the listening port. The client would not necessarily have been rejected in these cases. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connection_errors_tcpwrap`

Description: Number of connections the libwrap library refused. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Connections`

Description: Number of connection attempts (both successful and unsuccessful)
Scope: Global
Data Type: numeric

`Cpu_time`

Description: Total CPU time used. Part of . Requires the system variable to be set in order to be recorded.
Scope: Global, Session
Data Type: numeric

`Created_tmp_disk_tables`

Description: Number of on-disk temporary tables created.
Scope: Global, Session
Data Type: numeric

`Created_tmp_files`

Description: Number of temporary files created. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Created_tmp_tables`

Description: Number of in-memory temporary tables created.
Scope: Global
Data Type: numeric

`Delayed_errors`

Description: Number of errors which occurred while doing . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Delayed_insert_threads`

Description: Number of threads.
Scope: Global
Data Type: numeric

`Delayed_writes`

Description: Number of rows written. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Delete_scan`

Description: Number of s that required a full table scan.
Scope: Global
Data Type: numeric

`Empty_queries`

Description: Number of queries returning no results. Note this is not the same as .
Scope: Global, Session
Data Type: numeric

`Executed_events`

Description: Number of times events created with have executed. This differs from in that it is only incremented when the event has run, not when it executes.
Scope: Global, Session
Data Type: numeric

`Executed_triggers`

Description: Number of times triggers created with have executed. This differs from in that it is only incremented when the trigger has run, not when it executes.
Scope: Global, Session
Data Type: numeric

`Feature_application_time_periods`

Description: Number of times a table created with has been opened.
Scope: Global, Session
Data Type: numeric

`Feature_check_constraint`

Description: Number of times were checked. The global value can be flushed by .
Scope: Global, Session
Data Type: numeric

`Feature_custom_aggregate_functions`

Description: Number of queries which make use of .
Scope: Global, Session
Data Type: numeric

`Feature_delay_key_write`

Description: Number of tables opened that are using . The global value can be flushed by .
Scope: Global, Session
Data Type: numeric

`Feature_dynamic_columns`

Description: Number of times the function was used.
Scope: Global, Session
Data Type: numeric

`Feature_fulltext`

Description: Number of times the function was used.
Scope: Global, Session
Data Type: numeric

`Feature_gis`

Description: Number of times a table with a any of the columns was opened.
Scope: Global, Session
Data Type: numeric

`Feature_insert_returning`

Description:
Scope: Global, Session
Data Type: numeric
Introduced:

`Feature_invisible_columns`

Description: Number of invisible columns in all opened tables.
Scope: Global, Session
Data Type: numeric

`Feature_json`

Description: Number of times JSON functionality has been used, such as one of the . Does not include the , or .
Scope: Global, Session
Data Type: numeric

`Feature_locale`

Description: Number of times the variable was assigned into.
Scope: Global, Session
Data Type: numeric

`Feature_subquery`

Description: Number of subqueries (excluding subqueries in the FROM clause) used.
Scope: Global, Session
Data Type: numeric

`Feature_system_versioning`

Description: Number of times functionality has been used (opening a table WITH SYSTEM VERSIONING).
Scope: Global, Session
Data Type: numeric

`Feature_timezone`

Description: Number of times an explicit timezone (excluding and SYSTEM) was specified.
Scope: Global, Session
Data Type: numeric

`Feature_trigger`

Description: Number of triggers loaded.
Scope: Global, Session
Data Type: numeric

`Feature_window_functions`

Description: Number of times were used.
Scope: Global, Session
Data Type: numeric

`Feature_xml`

Description: Number of times XML functions ( and ) were used.
Scope: Global, Session
Data Type: numeric

`Flush_commands`

Description: Number of statements executed, as well as due to internal server flush requests. This differs from , which simply counts FLUSH statements, not internal server flush operations.
Scope: Global
Data Type: numeric
Removed:

`Handler_commit`

Description: Number of internal requests. Differs from , which counts the number of statements executed.
Scope: Global, Session
Data Type: numeric

`Handler_delete`

Description: Number of times rows have been deleted from tables. Differs from , which counts statements.
Scope: Global, Session
Data Type: numeric

`Handler_discover`

Description: Discovery is when the server asks the NDBCLUSTER storage engine if it knows about a table with a given name. Handler_discover indicates the number of times that tables have been discovered in this way.
Scope: Global, Session
Data Type: numeric

`Handler_external_lock`

Description: Incremented for each call to the external_lock() function, which generally occurs at the beginning and end of access to a table instance.
Scope: Global, Session
Data Type: numeric

`Handler_icp_attempts`

Description: Number of times pushed index condition was checked. The smaller the ratio of Handler_icp_attempts to the better the filtering. See .
Scope: Global, Session
Data Type: numeric

`Handler_icp_match`

Description: Number of times pushed index condition was matched. The smaller the ratio of to Handler_icp_match the better the filtering. See .
Scope: Global, Session
Data Type: numeric

`Handler_mrr_init`

Description: Counts how many MRR (multi-range read) scans were performed. See .
Scope: Global, Session
Data Type: numeric

`Handler_mrr_key_refills`

Description: Number of times key buffer was refilled (not counting the initial fill). A non-zero value indicates there wasn't enough memory to do key sort-and-sweep passes in one go. See .
Scope: Global, Session
Data Type: numeric

`Handler_mrr_rowid_refills`

Description: Number of times rowid buffer was refilled (not counting the initial fill). A non-zero value indicates there wasn't enough memory to do rowid sort-and-sweep passes in one go. See .
Scope: Global, Session
Data Type: numeric

`Handler_prepare`

Description: Number of two-phase commit prepares.
Scope: Global, Session
Data Type: numeric

`Handler_read_first`

Description: Number of requests to read the first row from an index. A high value indicates many full index scans, e.g. SELECT a FROM table_name where a is an indexed column.
Scope: Global, Session
Data Type: numeric

`Handler_read_key`

Description: Number of row read requests based on an index value. A high value indicates indexes are regularly being used, which is usually positive.
Scope: Global, Session
Data Type: numeric

`Handler_read_last`

Description: Number of requests to read the last row from an index. results in a last-key request followed by several previous-key requests.
Scope: Global, Session
Data Type: numeric

`Handler_read_next`

Description: Number of requests to read the next row from an index (in order). Increments when doing an index scan or querying an index column with a range constraint.
Scope: Global, Session
Data Type: numeric

`Handler_read_prev`

Description: Number of requests to read the previous row from an index (in order). Mostly used with .
Scope: Global, Session
Data Type: numeric

`Handler_read_retry`

Description: Number of read retrys triggered by semi_consistent_read (InnoDB feature).
Scope: Global
Data Type: numeric

`Handler_read_rnd`

Description: Number of requests to read a row based on its position. If this value is high, you may not be using joins that don't use indexes properly, or be doing many full table scans.
Scope: Global, Session
Data Type: numeric

`Handler_read_rnd_deleted`

Description: Number of requests to delete a row based on its position.
Scope: Global, Session
Data Type: numeric

`Handler_read_rnd_next`

Description: Number of requests to read the next row. A large number of these may indicate many table scans and improperly used indexes.
Scope: Global, Session
Data Type: numeric

`Handler_rollback`

Description: Number of transaction rollback requests given to a storage engine. Differs from , which is the number of commands executed.
Scope: Global, Session
Data Type: numeric

`Handler_savepoint`

Description: Number of transaction savepoint creation requests. Differs from which is the number of commands executed.
Scope: Global, Session
Data Type: numeric

`Handler_savepoint_rollback`

Description: Number of requests to rollback to a transaction .
Scope: Global, Session
Data Type: numeric

`Handler_tmp_delete`

Description: Number of requests to delete a row in a temporary table.
Scope: Global, Session
Data Type: numeric

`Handler_tmp_update`

Description: Number of requests to update a row to a temporary table.
Scope: Global, Session
Data Type: numeric

`Handler_tmp_write`

Description: Number of requests to write a row to a temporary table.
Scope: Global, Session
Data Type: numeric

`Handler_update`

Description: Number of requests to update a row in a table. Since , this no longer counts temporary tables - see .
Scope: Global, Session
Data Type: numeric

`Handler_write`

Description: Number of requests to write a row to a table. Since , this no longer counts temporary tables - see .
Scope: Global, Session
Data Type: numeric

`Key_blocks_not_flushed`

Description: Number of key cache blocks which have been modified but not flushed to disk.
Scope: Global
Data Type: numeric

`Key_blocks_unused`

Description: Number of unused key cache blocks.
Scope: Global
Data Type: numeric

`Key_blocks_used`

Description: Max number of key cache blocks which have been used simultaneously.
Scope: Global
Data Type: numeric

`Key_blocks_warm`

Description: Number of key cache blocks in the warm list.
Scope: Global
Data Type: numeric

`Key_read_requests`

Description: Number of key cache block read requests. See .
Scope: Global
Data Type: numeric

`Key_reads`

Description: Number of physical index block reads. See .
Scope: Global
Data Type: numeric

`Key_write_requests`

Description: Number of requests to write a block to the key cache.
Scope: Global
Data Type: numeric

`Key_writes`

Description: Number of key cache block write requests
Scope: Global
Data Type: numeric

`Last_query_cost`

Description: The most recent query optimizer query cost calculation. Can not be calculated for complex queries, such as subqueries or UNION. It will be set to 0 for complex queries.
Scope: Session
Data Type: numeric

`Maria_*`

Description: When the Maria storage engine was renamed Aria, the Maria variables existing at the time were renamed at the same time. See .

`Max_memory_used`

Description: The maximum memory allocation used by the current connection.
Scope: Session
Data Type: numeric
Introduced:

`Max_statement_time_exceeded`

Description: Number of queries that exceeded the execution time specified by . See .
Data Type: numeric

`Max_tmp_space_used`

Description: Maximum temporary space used. See
Scope: Global, Session
Data Type: numeric
Introduced:

`Max_used_connections`

Description: Max number of connections ever open at the same time. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Max_used_connections_time`

Description: The time at which the last change of occured. The global value can be flushed by .
Scope: Global
Data Type: datetime
Introduced: ,

`Memory_used`

Description: Global or per-connection memory usage, in bytes. This includes all per-connection memory allocations, and as of includes global allocations such as the key_buffer, innodb_buffer_pool etc (which were excluded before MariaDB 10.6.16).
Scope: Global, Session
Data Type: numeric

`Memory_used_initial`

Description: Amount of memory that was used when the server started to service the user connections.
Scope: Global
Data Type: numeric

`Not_flushed_delayed_rows`

Description: Number of rows waiting to be written.
Scope: Global
Data Type: numeric

`Open_files`

Description: Number of regular files currently opened by the server. Does not include sockets or pipes, or storage engines using internal functions.
Scope: Global
Data Type: numeric

`Open_streams`

Description: Number of currently opened streams, usually log files.
Scope: Global
Data Type: numeric

`Open_table_definitions`

Description: Number of currently cached .frm files.
Scope: Global
Data Type: numeric

`Open_tables`

Description: Number of currently opened tables, excluding temporary tables.
Scope: Global, Session
Data Type: numeric

`Opened_files`

Description: Number of files the server has opened.
Scope: Global
Data Type: numeric

`Opened_plugin_libraries`

Description: Number of shared libraries that the server has opened to load .
Scope: Global
Data Type: numeric

`Opened_table_definitions`

Description: Number of .frm files that have been cached.
Scope: Global, Session
Data Type: numeric

`Opened_tables`

Description: Number of tables the server has opened.
Scope: Global, Session
Data Type: numeric

`Opened_views`

Description: Number of views the server has opened.
Scope: Global, Session
Data Type: numeric

`Prepared_stmt_count`

Description: Current number of prepared statements.
Scope: Global
Data Type: numeric

`Qcache_free_blocks`

Description: Number of free memory blocks.
Scope: Global
Data Type: numeric

`Qcache_free_memory`

Description: Amount of free memory.
Scope: Global
Data Type: numeric

`Qcache_hits`

Description: Number of requests served by the . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Qcache_inserts`

Description: Number of queries ever cached in the . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Qcache_lowmem_prunes`

Description: Number of pruning operations performed to remove old results to make space for new results in the . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Qcache_not_cached`

Description: Number of queries that are uncacheable by the , or use SQL_NO_CACHE. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Qcache_queries_in_cache`

Description: Number of queries currently cached by the .
Scope: Global
Data Type: numeric

`Qcache_total_blocks`

Description: Number of blocks used by the .
Scope: Global
Data Type: numeric

`Queries`

Description: Number of statements executed by the server, excluding COM_PING and COM_STATISTICS. Differs from in that it also counts statements executed within .
Scope: Global, Session
Data Type: numeric

`Query_time`

Description: Cumulative time in seconds, with microsecond precision, of running queries.
Scope: Global,Session
Data Type: numeric
Introduced:

`Questions`

Description: Number of statements executed by the server, excluding COM_PING, COM_STATISTICS, COM_STMT_PREPARE, COM_STMT_CLOSE, and COM_STMT_RESET statements. Differs from in that it doesn't count statements executed within .
Scope: Global, Session
Data Type: numeric

`Resultset_metadata_skipped`

Description: Number of times sending the metadata has been skipped. Metadata is not resent if metadata does not change between prepare and execute of prepared statement, or between executes.
Scope: Global, Session
Data Type: numeric
Introduced:

`Rows_read`

Description: Number of requests to read a row (excluding temporary tables).
Scope: Global, Session
Data Type: numeric

`Rows_sent`

Description:
Scope: Global, Session
Data Type: numeric

`Rows_tmp_read`

Description: Number of requests to read a row in a temporary table.
Scope: Global, Session
Data Type: numeric

`Select_full_join`

Description: Number of joins which did not use an index. If not zero, you may need to check table indexes.
Scope: Global, Session
Data Type: numeric

`Select_full_range_join`

Description: Number of joins which used a range search of the first table.
Scope: Global, Session
Data Type: numeric

`Select_range`

Description: Number of joins which used a range on the first table.
Scope: Global, Session
Data Type: numeric

`Select_range_check`

Description: Number of joins without keys that check for key usage after each row. If not zero, you may need to check table indexes.
Scope: Global, Session
Data Type: numeric

`Select_scan`

Description: Number of joins which used a full scan of the first table.
Scope: Global, Session
Data Type: numeric

`Slow_launch_threads`

Description: Number of threads which took longer than to create. The global value can be flushed by .
Scope: Global, Session
Data Type: numeric

`Slow_queries`

Description: Number of queries which took longer than to run. The does not need to be active for this to be recorded.
Scope: Global, Session
Data Type: numeric

`Sort_merge_passes`

Description: Number of merge passes performed by the sort algorithm. If too high, you may need to look at improving your query indexes, or increasing the .
Scope: Global, Session
Data Type: numeric

`Sort_priority_queue_sorts`

Description: The number of times that sorting was done through a priority queue. (The total number of times sorting was done is a sum and ). See .
Scope: Global, Session
Data Type: numeric

`Sort_range`

Description: Number of sorts which used a range.
Scope: Global, Session
Data Type: numeric

`Sort_rows`

Description: Number of rows sorted.
Scope: Global, Session
Data Type: numeric

`Sort_scan`

Description: Number of sorts which used a full table scan.
Scope: Global, Session
Data Type: numeric

`Subquery_cache_hit`

Description: Counter for all hits. The global value can be flushed by .
Scope: Global, Session
Data Type: numeric

`Subquery_cache_miss`

Description: Counter for all misses. The global value can be flushed by .
Scope: Global, Session
Data Type: numeric

`Syncs`

Description: Number of times my_sync() has been called, or the number of times the server has had to force data to disk. Covers the , .frm creation (if these operations are configured to sync) and some storage engines (,, ), but not ).
Scope: Global, Session
Data Type: numeric

`Table_locks_immediate`

Description: Number of table locks which were completed immediately. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Table_locks_waited`

Description: Number of table locks which had to wait. Indicates table lock contention. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Table_open_cache_active_instances`

Description: Number of active instances for open tables cache lookups.
Scope:
Data Type: numeric

`Table_open_cache_hits`

Description: Number of hits for open tables cache lookups.
Scope:
Data Type: numeric

`Table_open_cache_misses`

Description: Number of misses for open tables cache lookups.
Scope:
Data Type: numeric

`Table_open_cache_overflows`

Description: Number of overflows for open tables cache lookups.
Scope:
Data Type: numeric

`Tc_log_max_pages_used`

Description: Max number of pages used by the memory-mapped file-based . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Tc_log_page_size`

Description: Page size of the memory-mapped file-based .
Scope: Global
Data Type: numeric

`Tc_log_page_waits`

Description: Number of times a two-phase commit was forced to wait for a free memory-mapped file-based page. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Threads_cached`

Description: Number of threads cached in the thread cache. This value will be zero if the is in use.
Scope: Global
Data Type: numeric

`Threads_connected`

Description: Number of clients connected to the server. See . The Threads_connected name is inaccurate when the is in use, since each client connection does not correspond to a dedicated thread in that case.
Scope: Global
Data Type: numeric

`Threads_created`

Description: Number of threads created to respond to client connections. If too large, look at increasing .
Scope: Global
Data Type: numeric

`Threads_running`

Description: Number of client connections that are actively running a command, and not just sleeping while waiting to receive the next command to execute. Some internal system threads also count towards this status variable if they would show up in the output of the statement.
- In and before, a global counter was updated each time a client connection dispatched a command. In these versions, the global and session status variable are always the same value.
- In and later, the global counter has been removed as a performance improvement. Instead, when the global status variable is queried, it is calculated dynamically by essentially adding up all the running client connections as they would appear in output. A client connection is only considered to be running if its thread value is not equal to Sleep

`Tmp_space_used`

Description: Temporary space used. See
Scope: Global, Session
Data Type: numeric
Introduced:

`Update_scan`

Description: Number of updates that required a full table scan.
Scope: Global
Data Type: numeric

`Uptime`

Description: Number of seconds the server has been running.
Scope: Global
Data Type: numeric

`Uptime_since_flush_status`

Description: Number of seconds since the last .
Scope: Global
Data Type: numeric

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