The Ultimate Guide to High Availability with MariaDB
This is a read-only copy of the MariaDB Knowledgebase generated on 2024-11-21. For the latest, interactive version please visit https://mariadb.com/kb/.

Performance Schema System Variables

Contents

  1. performance_schema
  2. performance_schema_accounts_size
  3. performance_schema_digests_size
  4. performance_schema_events_stages_history_long_size
  5. performance_schema_events_stages_history_size
  6. performance_schema_events_statements_history_long_size
  7. performance_schema_events_statements_history_size
  8. performance_schema_events_transactions_history_long_size
  9. performance_schema_events_transactions_history_size
  10. performance_schema_events_waits_history_long_size
  11. performance_schema_events_waits_history_size
  12. performance_schema_hosts_size
  13. performance_schema_max_cond_classes
  14. performance_schema_max_cond_instances
  15. performance_schema_max_digest_length
  16. performance_schema_max_file_classes
  17. performance_schema_max_file_handles
  18. performance_schema_max_file_instances
  19. performance_schema_max_index_stat
  20. performance_schema_max_memory_classes
  21. performance_schema_max_metadata_locks
  22. performance_schema_max_mutex_classes
  23. performance_schema_max_mutex_instances
  24. performance_schema_max_prepared_statement_instances
  25. performance_schema_max_program_instances
  26. performance_schema_max_rwlock_classes
  27. performance_schema_max_rwlock_instances
  28. performance_schema_max_socket_classes
  29. performance_schema_max_socket_instances
  30. performance_schema_max_sql_text_length
  31. performance_schema_max_stage_classes
  32. performance_schema_max_statement_classes
  33. performance_schema_max_statement_stack
  34. performance_schema_max_table_handles
  35. performance_schema_max_table_instances
  36. performance_schema_max_table_lock_stat
  37. performance_schema_max_thread_classes
  38. performance_schema_max_thread_instances
  39. performance_schema_session_connect_attrs_size
  40. performance_schema_setup_actors_size
  41. performance_schema_setup_objects_size
  42. performance_schema_users_size

The following variables are used with MariaDB's Performance Schema. See Performance Schema Options for Performance Schema options that are not system variables. See Server System Variables for a complete list of system variables and instructions on setting them.

See also the Full list of MariaDB options, system and status variables.

performance_schema

  • Description: If set to 1 (0 is default), enables the Performance Schema
  • Commandline: --performance-schema=#
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

performance_schema_accounts_size

  • Description: Maximum number of rows in the performance_schema.accounts table. If set to 0, the Performance Schema will not store statistics in the accounts table. Use -1 (the default) for automated sizing.
  • Commandline: --performance-schema-accounts-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_digests_size

  • Description: Maximum number of rows that can be stored in the events_statements_summary_by_digest table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-digests-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_events_stages_history_long_size

  • Description: Number of rows in the events_stages_history_long table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-stages-history-long-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_events_stages_history_size

  • Description: Number of rows per thread in the events_stages_history table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-stages-history-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1024

performance_schema_events_statements_history_long_size

  • Description: Number of rows in the events_statements_history_long table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-statements-history-long-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_events_statements_history_size

  • Description: Number of rows per thread in the events_statements_history table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-statements-history-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1024

performance_schema_events_transactions_history_long_size

  • Description: Number of rows in events_transactions_history_long table. Use 0 to disable, -1 for automated sizing.
  • Commandline: --performance-schema-events-transactions-history-long-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_events_transactions_history_size

  • Description:Number of rows per thread in events_transactions_history. Use 0 to disable, -1 for automated sizing.
  • Commandline: --performance-schema-events-transactions-history-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1024
  • Introduced: MariaDB 10.5.2

performance_schema_events_waits_history_long_size

  • Description: Number of rows contained in the events_waits_history_long table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-waits-history-long-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_events_waits_history_size

  • Description: Number of rows per thread contained in the events_waits_history table. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-events-waits-history-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1024

performance_schema_hosts_size

  • Description: Number of rows stored in the hosts table. If set to zero, no connection statistics are kept for the hosts table. -1 (the default) for automated sizing.
  • Commandline: --performance-schema-hosts-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_max_cond_classes

  • Description: Specifies the maximum number of condition instruments.
  • Commandline: --performance-schema-max-cond-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 90 (>= MariaDB 10.5.1), 80 (<= MariaDB 10.5.0)
  • Range: 0 to 256

performance_schema_max_cond_instances

  • Description: Specifies the maximum number of instrumented condition objects. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-cond-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_max_digest_length

  • Description: Maximum length considered for digest text, when stored in performance_schema tables.
  • Commandline: --performance-schema-max-digest-length=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 1024
  • Range: 0 to 1048576

performance_schema_max_file_classes

  • Description: Specifies the maximum number of file instruments.
  • Commandline: --performance-schema-max-file-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:80 (>= MariaDB 10.5.2), 50 (<= MariaDB 10.5.1)
  • Range: 0 to 256

performance_schema_max_file_handles

  • Description: Specifies the maximum number of opened file objects. Should always be higher than open_files_limit.
  • Commandline: --performance-schema-max-file-handles=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 32768
  • Range: -1 to 32768

performance_schema_max_file_instances

  • Description: Specifies the maximum number of instrumented file objects. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-file-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_max_index_stat

  • Description: Maximum number of index statistics for instrumented tables. Use 0 to disable, -1 for automated scaling.
  • Commandline: --performance-schema-max-index-stat=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_max_memory_classes

  • Description: Maximum number of memory pool instruments.
  • Commandline: --performance-schema-max-memory-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 320
  • Range: 0 to 1024
  • Introduced: MariaDB 10.5.2

performance_schema_max_metadata_locks

  • Description: Maximum number of Performance Schema metadata locks. Use 0 to disable, -1 for automated scaling.
  • Commandline: --performance-schema-max-metadata-locks=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 104857600
  • Introduced: MariaDB 10.5.2

performance_schema_max_mutex_classes

  • Description: Specifies the maximum number of mutex instruments.
  • Commandline: --performance-schema-max-mutex-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 210 (>= MariaDB 10.5.2), 200 (<= MariaDB 10.5.1)
  • Range: 0 to 256

performance_schema_max_mutex_instances

  • Description: Specifies the maximum number of instrumented mutex instances. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-mutex-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:-1
  • Range: -1 to 104857600

performance_schema_max_prepared_statement_instances

  • Description: Maximum number of instrumented prepared statements. Use 0 to disable, -1 for automated scaling.
  • Commandline: --performance-schema-max-prepared-statement-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_max_program_instances

  • Description: Maximum number of instrumented programs. Use 0 to disable, -1 for automated scaling.
  • Commandline: --performance-schema-max-program-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_max_rwlock_classes

  • Description: Specifies the maximum number of rwlock instruments.
  • Commandline: --performance-schema-max-rwlock-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 50 (>= MariaDB 10.5.2), 40 (<= MariaDB 10.5.1)
  • Range: 0 to 256

performance_schema_max_rwlock_instances

  • Description: Specifies the maximum number of instrumented rwlock objects. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-rwlock-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:-1
  • Range: -1 to 104857600

performance_schema_max_socket_classes

  • Description: Specifies the maximum number of socket instruments.
  • Commandline: --performance-schema-max-socket-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 10
  • Range: 0 to 256

performance_schema_max_socket_instances

  • Description: Specifies the maximum number of instrumented socket objects. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-socket-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:-1
  • Range: -1 to 1048576

performance_schema_max_sql_text_length

  • Description: Maximum length of displayed sql text.
  • Commandline: --performance-schema-max-sql-text-length=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 1024
  • Range: 0 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_max_stage_classes

  • Description: Specifies the maximum number of stage instruments.
  • Commandline: --performance-schema-max-stage-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 160
  • Range: 0 to 256

performance_schema_max_statement_classes

  • Description: Specifies the maximum number of statement instruments. Automatically calculated at server build based on the number of available statements. Should be left as either autosized or disabled, as changing to any positive value has no benefit and will most likely allocate unnecessary memory. Setting to zero disables all statement instrumentation, and no memory will be allocated for this purpose.
  • Commandline: --performance-schema-max-statement-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: Autosized (see description)
  • Range: 0 to 256

performance_schema_max_statement_stack

  • Description: Number of rows per thread in EVENTS_STATEMENTS_CURRENT.
  • Commandline: --performance-schema-max-statement-stack=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 10
  • Range: 1 to 256
  • Introduced: MariaDB 10.5.2

performance_schema_max_table_handles

  • Description: Specifies the maximum number of opened table objects. 0 for disabling, -1 (the default) for automated sizing. See also the Performance Schema table_handles table.
  • Commandline: --performance-schema-max-table-handles=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_max_table_instances

  • Description: Specifies the maximum number of instrumented table objects. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-table-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:-1
  • Range: -1 to 1048576

performance_schema_max_table_lock_stat

  • Description: Maximum number of lock statistics for instrumented tables. Use 0 to disable, -1 for automated scaling.
  • Commandline: --performance-schema-max-table-lock-stat=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
  • Introduced: MariaDB 10.5.2

performance_schema_max_thread_classes

  • Description: Specifies the maximum number of thread instruments.
  • Commandline: --performance-schema-max-thread-classes=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 50
  • Range: 0 to 256

performance_schema_max_thread_instances

  • Description: Specifies how many of the running server threads (see max_connections and max_delayed_threads) can be instrumented. Should be greater than the sum of max_connections and max_delayed_threads. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-max-thread-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:-1
  • Range: -1 to 1048576

performance_schema_session_connect_attrs_size

  • Description: Per thread preallocated memory for holding connection attribute strings. Incremented if the strings are larger than the reserved space. 0 for disabling, -1 (the default) for automated sizing.
  • Commandline: --performance-schema-session-connect-attrs-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576

performance_schema_setup_actors_size

performance_schema_setup_objects_size

performance_schema_users_size

  • Description: Number of rows in the performance_schema.users table. If set to 0, the Performance Schema will not store connection statistics in the users table. -1 (the default) for automated sizing.
  • Commandline: --performance-schema-users-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: -1
  • Range: -1 to 1048576
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