Server System Variables

Contents

  1. About the Server System Variables
  2. Setting Server System Variables
  3. List of Server System Variables
    1. allow_suspicious_udfs
    2. alter_algorithm
    3. analyze_sample_percentage
    4. aria_block_size
    5. aria_checkpoint_interval
    6. aria_checkpoint_log_activity
    7. aria_encrypt_tables
    8. aria_force_start_after_recovery_failures
    9. aria_group_commit
    10. aria_group_commit_interval
    11. aria_log_file_size
    12. aria_log_purge_type
    13. aria_max_sort_file_size
    14. aria_page_checksum
    15. aria_pagecache_age_threshold
    16. aria_pagecache_buffer_size
    17. aria_pagecache_division_limit
    18. aria_pagecache_file_hash_size
    19. aria_recover
    20. aria_repair_threads
    21. aria_sort_buffer_size
    22. aria_stats_method
    23. aria_sync_log_dir
    24. aria_used_for_temp_tables
    25. auto_increment_increment
    26. auto_increment_offset
    27. autocommit
    28. automatic_sp_privileges
    29. aws_key_management_key_spec
    30. aws_key_management_log_level
    31. aws_key_management_master_key_id
    32. aws_key_management_mock
    33. aws_key_management_region
    34. aws_key_management_request_timeout
    35. aws_key_management_rotate_key
    36. back_log
    37. basedir
    38. big_tables
    39. bind_address
    40. binlog_alter_two_phase
    41. binlog_annotate_row_events
    42. binlog_cache_size
    43. binlog_checksum
    44. binlog_commit_wait_count
    45. binlog_commit_wait_usec
    46. binlog_direct_non_transactional_updates
    47. binlog_do_db
    48. binlog_expire_logs_seconds
    49. binlog_file_cache_size
    50. binlog_format
    51. binlog_gtid_index
    52. binlog_gtid_index_page_size
    53. binlog_gtid_index_span_min
    54. binlog_ignore_db
    55. binlog_optimize_thread_scheduling
    56. binlog_do_db
    57. binlog_row_event_max_size
    58. binlog_row_metadata
    59. binlog_stmt_cache_size
    60. block_encryption_mode
    61. bulk_insert_buffer_size
    62. cassandra_default_thrift_host
    63. cassandra_failure_retries
    64. cassandra_insert_batch_size
    65. cassandra_multiget_batch_size
    66. cassandra_read_consistency
    67. cassandra_rnd_batch_size
    68. cassandra_write_consistency
    69. character_set_client
    70. character_set_collations
    71. character_set_connection
    72. character_set_database
    73. character_set_filesystem
    74. character_set_results
    75. character_set_server
    76. character_set_system
    77. character_sets_dir
    78. check_constraint_checks
    79. collation_connection
    80. collation_database
    81. collation_server
    82. column_compression_threshold
    83. column_compression_zlib_level
    84. column_compression_zlib_strategy
    85. column_compression_zlib_wrap
    86. completion_type
    87. concurrent_insert
    88. connect_class_path
    89. connect_cond_push
    90. connect_conv_size
    91. connect_default_depth
    92. connect_default_prec
    93. connect_enable_mongo
    94. connect_exact_info
    95. connect_force_bson
    96. connect_indx_map
    97. connect_java_wrapper
    98. connect_json_all_path
    99. connect_json_grp_size
    100. connect_json_null
    101. connect_jvm_path
    102. connect_timeout
    103. connect_type_conv
    104. connect_use_tempfile
    105. connect_work_size
    106. connect_xtrace
    107. core_file
    108. cracklib_password_check
    109. cracklib_password_check_dictionary
    110. datadir
    111. date_format
    112. datetime_format
    113. deadlock_search_depth_long
    114. deadlock_search_depth_short
    115. deadlock_timeout_long
    116. deadlock_timeout_short
    117. debug/debug_dbug
    118. debug_no_thread_alarm
    119. debug_sync
    120. default_master_connection
    121. default_password_lifetime
    122. default_regex_flags
    123. default_storage_engine
    124. default_table_type
    125. default_tmp_storage_engine
    126. default_week_format
    127. delay_key_write
    128. delayed_insert_limit
    129. delayed_insert_timeout
    130. delayed_queue_size
    131. disconnect_on_expired_password
    132. div_precision_increment
    133. encrypt_binlog
    134. encrypt_tmp_disk_tables
    135. encrypt_tmp_files
    136. encryption_algorithm
    137. enforce_storage_engine
    138. engine_condition_pushdown
    139. eq_range_index_dive_limit
    140. error_count
    141. event_scheduler
    142. expensive_subquery_limit
    143. expire_logs_days
    144. explicit_defaults_for_timestamp
    145. external_user
    146. extra_max_connections
    147. extra_port
    148. feedback
    149. feedback_http_proxy
    150. feedback_send_retry_wait
    151. feedback_send_timeout
    152. feedback_server_uid
    153. feedback_url
    154. feedback_user_info
    155. file_key_management_encryption_algorithm
    156. file_key_management_filekey
    157. file_key_management_filename
    158. flush
    159. flush_time
    160. foreign_key_checks
    161. ft_boolean_syntax
    162. ft_max_word_len
    163. ft_min_word_len
    164. ft_query_expansion_limit
    165. ft_stopword_file
    166. general_log
    167. general_log_file
    168. group_concat_max_len
    169. gssapi_keytab_path
    170. gssapi_principal_name
    171. gssapi_mech_name
    172. gtid_binlog_pos
    173. gtid_binlog_state
    174. gtid_cleanup_batch_size
    175. gtid_current_pos
    176. gtid_domain_id
    177. gtid_ignore_duplicates
    178. gtid_seq_no
    179. gtid_slave_pos
    180. gtid_strict_mode
    181. gtid_pos_auto_engines
    182. handlersocket_accept_balance
    183. handlersocket_address
    184. handlersocket_backlog
    185. handlersocket_epoll
    186. handlersocket_port
    187. handlersocket_port_wr
    188. handlersocket_sndbuf
    189. handlersocket_rcvbuf
    190. handlersocket_readsize
    191. handlersocket_threads
    192. handlersocket_threads_wr
    193. handlersocket_timeout
    194. handlersocket_verbose
    195. handlersocket_wrlock_timeout
    196. have_compress
    197. have_crypt
    198. have_csv
    199. have_dynamic_loading
    200. have_geometry
    201. have_innodb
    202. have_ndbcluster
    203. have_openssl
    204. have_partitioning
    205. have_profiling
    206. have_query_cache
    207. have_rtree_keys
    208. have_ssl
    209. have_symlink
    210. histogram_size
    211. histogram_type
    212. host_cache_size
    213. hostname
    214. identity
    215. ignore_builtin_innodb
    216. idle_readonly_transaction_timeout
    217. idle_transaction_timeout
    218. idle_write_transaction_timeout
    219. ignore_db_dirs
    220. in_predicate_conversion_threshold
    221. in_transaction
    222. init_connect
    223. init_file
    224. init_slave
    225. innodb_adaptive_checkpoint
    226. innodb_adaptive_flushing
    227. innodb_adaptive_flushing_lwm
    228. innodb_adaptive_flushing_method
    229. innodb_adaptive_hash_index
    230. innodb_adaptive_hash_index_partitions
    231. innodb_adaptive_hash_index_parts
    232. innodb_adaptive_max_sleep_delay
    233. innodb_additional_mem_pool_size
    234. innodb_api_bk_commit_interval
    235. innodb_api_disable_rowlock
    236. innodb_api_enable_binlog
    237. innodb_api_enable_mdl
    238. innodb_api_trx_level
    239. innodb_auto_lru_dump
    240. innodb_autoextend_increment
    241. innodb_autoinc_lock_mode
    242. innodb_background_scrub_data_check_interval
    243. innodb_background_scrub_data-compressed
    244. innodb_background_scrub_data_interval
    245. innodb_background_scrub_data-uncompressed
    246. innodb_blocking_buffer_pool_restore
    247. innodb_buf_dump_status_frequency
    248. innodb_buffer_pool_chunk_size
    249. innodb_buffer_pool_dump_at_shutdown
    250. innodb_buffer_pool_dump_now
    251. innodb_buffer_pool_evict
    252. innodb_buffer_pool_filename
    253. innodb_buffer_pool_instances
    254. innodb_buffer_pool_load_abort
    255. innodb_buffer_pool_load_at_startup
    256. innodb_buffer_pool_load_now
    257. innodb_buffer_pool_load_pages_abort
    258. innodb_buffer_pool_populate
    259. innodb_buffer_pool_restore_at_startup
    260. innodb_buffer_pool_shm_checksum
    261. innodb_buffer_pool_shm_key
    262. innodb_buffer_pool_size
    263. innodb_change_buffer_dump
    264. innodb_change_buffer_max_size
    265. innodb_change_buffering
    266. innodb_change_buffering_debug
    267. innodb_checkpoint_age_target
    268. innodb_checksum_algorithm
    269. innodb_checksums
    270. innodb_cleaner_lsn_age_factor
    271. innodb_cmp_per_index_enabled
    272. innodb_commit_concurrency
    273. innodb_compression_algorithm
    274. innodb_compression_default
    275. innodb_compression_failure_threshold_pct
    276. innodb_compression_level
    277. innodb_compression_pad_pct_max
    278. innodb_concurrency_tickets
    279. innodb_corrupt_table_action
    280. innodb_data_file_buffering
    281. innodb_data_file_path
    282. innodb_data_file_write_through
    283. innodb_data_home_dir
    284. innodb_deadlock_detect
    285. innodb_deadlock_report
    286. innodb_default_encryption_key_id
    287. innodb_default_page_encryption_key
    288. innodb_default_row_format
    289. innodb_defragment
    290. innodb_defragment_fill_factor
    291. innodb_defragment_fill_factor_n_recs
    292. innodb_defragment_frequency
    293. innodb_defragment_n_pages
    294. innodb_defragment_stats_accuracy
    295. innodb_dict_size_limit
    296. innodb_disable_sort_file_cache
    297. innodb_disallow_writes
    298. innodb_doublewrite
    299. innodb_doublewrite_file
    300. innodb_empty_free_list_algorithm
    301. innodb_enable_unsafe_group_commit
    302. innodb_encrypt_log
    303. innodb_encrypt_tables
    304. innodb_encrypt_temporary_tables
    305. innodb_encryption_rotate_key_age
    306. innodb_encryption_rotation_iops
    307. innodb_encryption_threads
    308. innodb_extra_rsegments
    309. innodb_extra_undoslots
    310. innodb_fake_changes
    311. innodb_fast_checksum
    312. innodb_fast_shutdown
    313. innodb_fatal_semaphore_wait_threshold
    314. innodb_file_format
    315. innodb_file_format_check
    316. innodb_file_format_max
    317. innodb_file_per_table
    318. innodb_fill_factor
    319. innodb_flush_log_at_timeout
    320. innodb_flush_log_at_trx_commit
    321. innodb_flush_method
    322. innodb_flush_neighbor_pages
    323. innodb_flush_neighbors
    324. innodb_flush_sync
    325. innodb_flushing_avg_loops
    326. innodb_force_load_corrupted
    327. innodb_force_primary_key
    328. innodb_force_recovery
    329. innodb_foreground_preflush
    330. innodb_ft_aux_table
    331. innodb_ft_cache_size
    332. innodb_ft_enable_diag_print
    333. innodb_ft_enable_stopword
    334. innodb_ft_max_token_size
    335. innodb_ft_min_token_size
    336. innodb_ft_num_word_optimize
    337. innodb_ft_result_cache_limit
    338. innodb_ft_server_stopword_table
    339. innodb_ft_sort_pll_degree
    340. innodb_ft_total_cache_size
    341. innodb_ft_user_stopword_table
    342. innodb_ibuf_accel_rate
    343. innodb_ibuf_active_contract
    344. innodb_ibuf_max_size
    345. innodb_idle_flush_pct
    346. innodb_immediate_scrub_data-uncompressed
    347. innodb_import_table_from_xtrabackup
    348. innodb_instant_alter_column_allowed
    349. innodb_instrument_semaphores
    350. innodb_io_capacity
    351. innodb_io_capacity_max
    352. innodb_kill_idle_transaction
    353. innodb_large_prefix
    354. innodb_lazy_drop_table
    355. innodb_lock_schedule_algorithm
    356. innodb_lock_wait_timeout
    357. innodb_locking_fake_changes
    358. innodb_locks_unsafe_for_binlog
    359. innodb_log_arch_dir
    360. innodb_log_arch_expire_sec
    361. innodb_log_archive
    362. innodb_log_block_size
    363. innodb_log_buffer_size
    364. innodb_log_checksum_algorithm
    365. innodb_log_checksums
    366. innodb_log_compressed_pages
    367. innodb_log_file_size
    368. innodb_log_file_write_through
    369. innodb_log_files_in_group
    370. innodb_log_group_home_dir
    371. innodb_log_optimize_ddl
    372. innodb_log_write_ahead_size
    373. innodb_lru_flush_size
    374. innodb_lru_scan_depth
    375. innodb_max_bitmap_file_size
    376. innodb_max_changed_pages
    377. innodb_max_dirty_pages_pct
    378. innodb_max_dirty_pages_pct_lwm
    379. innodb_max_purge_lag
    380. innodb_max_purge_lag_delay
    381. innodb_max_purge_lag_wait
    382. innodb_max_undo_log_size
    383. innodb_merge_sort_block_size
    384. innodb_mirrored_log_groups
    385. innodb_monitor_disable
    386. innodb_monitor_enable
    387. innodb_monitor_reset
    388. innodb_monitor_reset_all
    389. innodb_mtflush_threads
    390. innodb_numa_interleave
    391. innodb_old_blocks_pct
    392. innodb_old_blocks_time
    393. innodb_online_alter_log_max_size
    394. innodb_open_files
    395. innodb_optimize_fulltext_only
    396. innodb_page_cleaners
    397. innodb_page_size
    398. innodb_prefix_index_cluster_optimization
    399. innodb_print_all_deadlocks
    400. innodb_purge_batch_size
    401. innodb_purge_rseg_truncate_frequency
    402. innodb_purge_threads
    403. innodb_random_read_ahead
    404. innodb_read_ahead
    405. innodb_read_ahead_threshold
    406. innodb_read_io_threads
    407. innodb_read_only
    408. innodb_recovery_stats
    409. innodb_recovery_update_relay_log
    410. innodb_replication_delay
    411. innodb_rollback_on_timeout
    412. innodb_rollback_segments
    413. innodb_safe_truncate
    414. innodb_sched_priority_cleaner
    415. innodb_scrub_log
    416. innodb_scrub_log_interval
    417. innodb_scrub_log_speed
    418. innodb_show_locks_held
    419. innodb_show_verbose_locks
    420. innodb_simulate_comp_failures
    421. innodb_sort_buffer_size
    422. innodb_spin_wait_delay
    423. innodb_stats_auto_recalc
    424. innodb_stats_auto_update
    425. innodb_stats_include_delete_marked
    426. innodb_stats_method
    427. innodb_stats_modified_counter
    428. innodb_stats_on_metadata
    429. innodb_stats_persistent
    430. innodb_stats_persistent_sample_pages
    431. innodb_stats_sample_pages
    432. innodb_stats_traditional
    433. innodb_stats_transient_sample_pages
    434. innodb_stats_update_need_lock
    435. innodb_status_output
    436. innodb_status_output_locks
    437. innodb_strict_mode
    438. innodb_support_xa
    439. innodb_sync_array_size
    440. innodb_sync_spin_loops
    441. innodb_table_locks
    442. innodb_temp_data_file_path
    443. innodb_thread_concurrency
    444. innodb_thread_concurrency_timer_based
    445. innodb_thread_sleep_delay
    446. innodb_tmpdir
    447. innodb_track_changed_pages
    448. innodb_track_redo_log_now
    449. innodb_truncate_temporary_tablespace_now
    450. innodb_undo_directory
    451. innodb_undo_log_truncate
    452. innodb_undo_logs
    453. innodb_use_atomic_writes
    454. innodb_use_fallocate
    455. innodb_use_global_flush_log_at_trx_commit
    456. innodb_use_native_aio
    457. innodb_use_purge_thread
    458. innodb_use_stacktrace
    459. innodb_use_sys_malloc
    460. innodb_use_sys_stats_table
    461. innodb_version
    462. innodb_write_io_threads
    463. insert_id
    464. interactive_timeout
    465. join_buffer_size
    466. join_buffer_space_limit
    467. join_cache_level
    468. keep_files_on_create
    469. key_buffer_size
    470. key_cache_age_threshold
    471. key_cache_block_size
    472. key_cache_division_limit
    473. key_cache_file_hash_size
    474. key_cache_segments
    475. large_files_support
    476. large_page_size
    477. large_pages
    478. last_gtid
    479. last_insert_id
    480. lc_messages
    481. lc_messages_dir
    482. lc_time_names
    483. license
    484. local_infile
    485. lock_wait_timeout
    486. locked_in_memory
    487. log
    488. log_bin
    489. log_bin_basename
    490. log_bin_compress
    491. log_bin_compress_min_len
    492. log_bin_index
    493. log_bin_trust_function_creators
    494. log_disabled_statements
    495. log_error
    496. log_output
    497. log_queries_not_using_indexes
    498. log_slave_updates
    499. log_slow_admin_statements
    500. log_slow_always_query_time
    501. log_slow_disabled_statements
    502. log_slow_filter
    503. log_slow_min_examined_row_limit
    504. log_slow_queries
    505. log_slow_query
    506. log_slow_query_file
    507. log_slow_query_time
    508. log_slow_rate_limit
    509. log_slow_slave_statements
    510. log_slow_verbosity
    511. log_slow_max_warnings
    512. log_tc_size
    513. log_warnings
    514. long_query_time
    515. low_priority_updates
    516. lower_case_file_system
    517. lower_case_table_names
    518. master_verify_checksum
    519. max_allowed_packet
    520. max_binlog_cache_size
    521. max_binlog_size
    522. max_binlog_stmt_cache_size
    523. max_binlog_total_size
    524. max_connect_errors
    525. max_connections
    526. max_delayed_threads
    527. max_digest_length
    528. max_error_count
    529. max_heap_table_size
    530. max_insert_delayed_threads
    531. max_join_size
    532. max_length_for_sort_data
    533. max_long_data_size
    534. max_password_errors
    535. max_prepared_stmt_count
    536. max_recursive_iterations
    537. max_relay_log_size
    538. max_rowid_filter_size
    539. max_seeks_for_key
    540. max_session_mem_used
    541. max_sort_length
    542. max_sp_recursion_depth
    543. max_statement_time
    544. max_tmp_space_usage
    545. max_tmp_tables
    546. max_total_tmp_space_usage
    547. max_user_connections
    548. max_write_lock_count
    549. metadata_locks_cache_size
    550. metadata_locks_hash_instances
    551. min_examined_row_limit
    552. mroonga_action_on_fulltext_query_error
    553. mroonga_boolean_mode_syntax_flags
    554. mroonga_database_path_prefix
    555. mroonga_default_parser
    556. mroonga_default_tokenizer
    557. mroonga_default_wrapper_engine
    558. mroonga_dry_write
    559. mroonga_enable_operations_recording
    560. mroonga_enable_optimization
    561. mroonga_libgroonga_embedded
    562. mroonga_libgroonga_support_zlib
    563. mroonga_libgroonga_support_zstd
    564. mroonga_libgroonga_version
    565. mroonga_log_file
    566. mroonga_log_level
    567. mroonga_match_escalation_threshold
    568. mroonga_max_n_records_for_estimate
    569. mroonga_query_log_file
    570. mroonga_vector_column_delimiter
    571. mroonga_version
    572. mrr_buffer_size
    573. multi_range_count
    574. myisam_block_size
    575. myisam_data_pointer_size
    576. myisam_max_sort_file_size
    577. myisam_mmap_size
    578. myisam_recover_options
    579. myisam_repair_threads
    580. myisam_sort_buffer_size
    581. myisam_stats_method
    582. myisam_use_mmap
    583. mysql56_temporal_format
    584. named_pipe
    585. net_buffer_length
    586. net_read_timeout
    587. net_retry_count
    588. net_write_timeout
    589. note_verbosity
    590. old
    591. old_alter_table
    592. old_mode
    593. old_passwords
    594. open_files_limit
    595. optimizer_adjust_secondary_key_costs
    596. optimizer_extra_pruning_depth
    597. optimizer_max_sel_args
    598. optimizer_max_sel_arg_weight
    599. optimizer_prune_level
    600. optimizer_search_depth
    601. optimizer_selectivity_sampling_limit
    602. optimizer_switch
    603. optimizer_trace
    604. optimizer_trace_max_mem_size
    605. optimizer_use_condition_selectivity
    606. oqgraph_allow_create_integer_latch
    607. pam_debug
    608. pam_use_cleartext_plugin
    609. pam_winbind_workaround
    610. performance_schema
    611. performance_schema_accounts_size
    612. performance_schema_digests_size
    613. performance_schema_events_stages_history_long_size
    614. performance_schema_events_stages_history_size
    615. performance_schema_events_statements_history_long_size
    616. performance_schema_events_statements_history_size
    617. performance_schema_events_transactions_history_long_size
    618. performance_schema_events_transactions_history_size
    619. performance_schema_events_waits_history_long_size
    620. performance_schema_events_waits_history_size
    621. performance_schema_hosts_size
    622. performance_schema_max_cond_classes
    623. performance_schema_max_cond_instances
    624. performance_schema_max_digest_length
    625. performance_schema_max_file_classes
    626. performance_schema_max_file_handles
    627. performance_schema_max_file_instances
    628. performance_schema_max_index_stat
    629. performance_schema_max_memory_classes
    630. performance_schema_max_metadata_locks
    631. performance_schema_max_mutex_classes
    632. performance_schema_max_mutex_instances
    633. performance_schema_max_prepared_statement_instances
    634. performance_schema_max_program_instances
    635. performance_schema_max_sql_text_length
    636. performance_schema_max_rwlock_classes
    637. performance_schema_max_rwlock_instances
    638. performance_schema_max_socket_classes
    639. performance_schema_max_socket_instances
    640. performance_schema_max_stage_classes
    641. performance_schema_max_statement_classes
    642. performance_schema_max_statement_stack
    643. performance_schema_max_table_handles
    644. performance_schema_max_table_instances
    645. performance_schema_max_table_lock_stat
    646. performance_schema_max_thread_classes
    647. performance_schema_max_thread_instances
    648. performance_schema_session_connect_attrs_size
    649. performance_schema_setup_actors_size
    650. performance_schema_setup_objects_size
    651. performance_schema_users_size
    652. pid_file
    653. plugin_dir
    654. plugin_maturity
    655. port
    656. preload_buffer_size
    657. profiling
    658. profiling_history_size
    659. progress_report_time
    660. protocol_version
    661. proxy_protocol_networks
    662. proxy_user
    663. pseudo_slave_mode
    664. pseudo_thread_id
    665. query_alloc_block_size
    666. query_cache_limit
    667. query_cache_min_res_unit
    668. query_cache_size
    669. query_cache_strip_comments
    670. query_cache_type
    671. query_cache_wlock_invalidate
    672. query_prealloc_size
    673. query_response_time_flush
    674. query_response_time_range_base
    675. query_response_time_range_exec_time_debug
    676. query_response_time_stats
    677. rand_seed1
    678. rand_seed2
    679. range_alloc_block_size
    680. read_binlog_speed_limit
    681. read_buffer_size
    682. read_only
    683. read_rnd_buffer_size
    684. redirect_url
    685. relay_log
    686. relay_log_basename
    687. relay_log_index
    688. relay_log_info_file
    689. relay_log_purge
    690. relay_log_recovery
    691. relay_log_space_limit
    692. replicate_annotate_row_events
    693. replicate_do_db
    694. replicate_do_table
    695. replicate_events_marked_for_skip
    696. replicate_ignore_db
    697. replicate_ignore_table
    698. replicate_rewrite_db
    699. replicate_wild_do_table
    700. replicate_wild_ignore_table
    701. report_host
    702. report_password
    703. report_port
    704. report_user
    705. require_secure_transport
    706. rocksdb_access_hint_on_compaction_start
    707. rocksdb_advise_random_on_open
    708. rocksdb_allow_concurrent_memtable_write
    709. rocksdb_allow_mmap_reads
    710. rocksdb_allow_mmap_writes
    711. rocksdb_allow_to_start_after_corruption
    712. rocksdb_background_sync
    713. rocksdb_base_background_compactions
    714. rocksdb_blind_delete_primary_key
    715. rocksdb_block_cache_size
    716. rocksdb_block_restart_interval
    717. rocksdb_block_size
    718. rocksdb_block_size_deviation
    719. rocksdb_bulk_load
    720. rocksdb_bulk_load_allow_sk
    721. rocksdb_bulk_load_allow_unsorted
    722. rocksdb_bulk_load_size
    723. rocksdb_bytes_per_sync
    724. rocksdb_cache_dump
    725. rocksdb_cache_high_pri_pool_ratio
    726. rocksdb_cache_index_and_filter_blocks
    727. rocksdb_cache_index_and_filter_with_high_priority
    728. rocksdb_checksums_pct
    729. rocksdb_collect_sst_properties
    730. rocksdb_commit_in_the_middle
    731. rocksdb_commit_time_batch_for_recovery
    732. rocksdb_compact_cf
    733. rocksdb_compaction_readahead_size
    734. rocksdb_compaction_sequential_deletes
    735. rocksdb_compaction_sequential_deletes_count_sd
    736. rocksdb_compaction_sequential_deletes_file_size
    737. rocksdb_compaction_sequential_deletes_window
    738. rocksdb_concurrent_prepare
    739. rocksdb_create_checkpoint
    740. rocksdb_create_if_missing
    741. rocksdb_create_missing_column_families
    742. rocksdb_datadir
    743. rocksdb_db_write_buffer_size
    744. rocksdb_deadlock_detect
    745. rocksdb_deadlock_detect_depth
    746. rocksdb_debug_manual_compaction_delay
    747. rocksdb_debug_optimizer_no_zero_cardinality
    748. rocksdb_debug_ttl_ignore_pk
    749. rocksdb_debug_ttl_read_filter_ts
    750. rocksdb_debug_ttl_rec_ts
    751. rocksdb_debug_ttl_snapshot_ts
    752. rocksdb_default_cf_options
    753. rocksdb_delayed_write_rate
    754. rocksdb_delete_cf
    755. rocksdb_delete_obsolete_files_period_micros
    756. rocksdb_enable_2pc
    757. rocksdb_enable_bulk_load_api
    758. rocksdb_enable_insert_with_update_caching
    759. rocksdb_enable_thread_tracking
    760. rocksdb_enable_ttl
    761. rocksdb_enable_ttl_read_filtering
    762. rocksdb_enable_write_thread_adaptive_yield
    763. rocksdb_error_if_exists
    764. rocksdb_error_on_suboptimal_collation
    765. rocksdb_flush_log_at_trx_commit
    766. rocksdb_flush_memtable_on_analyze
    767. rocksdb_force_compute_memtable_stats
    768. rocksdb_force_compute_memtable_stats_cachetime
    769. rocksdb_force_flush_memtable_and_lzero_now
    770. rocksdb_force_flush_memtable_now
    771. rocksdb_force_index_records_in_range
    772. rocksdb_git_hash
    773. rocksdb_hash_index_allow_collision
    774. rocksdb_ignore_unknown_options
    775. rocksdb_index_type
    776. rocksdb_info_log_level
    777. rocksdb_io_write_timeout
    778. rocksdb_is_fd_close_on_exec
    779. rocksdb_keep_log_file_num
    780. rocksdb_large_prefix
    781. rocksdb_lock_scanned_rows
    782. rocksdb_lock_wait_timeout
    783. rocksdb_log_dir
    784. rocksdb_log_file_time_to_roll
    785. rocksdb_manifest_preallocation_size
    786. rocksdb_manual_compaction_threads
    787. rocksdb_manual_wal_flush
    788. rocksdb_master_skip_tx_api
    789. rocksdb_max_background_compactions
    790. rocksdb_max_background_flushes
    791. rocksdb_max_background_jobs
    792. rocksdb_max_latest_deadlocks
    793. rocksdb_max_log_file_size
    794. rocksdb_max_manifest_file_size
    795. rocksdb_max_manual_compactions
    796. rocksdb_max_open_files
    797. rocksdb_max_row_locks
    798. rocksdb_max_subcompactions
    799. rocksdb_max_total_wal_size
    800. rocksdb_merge_buf_size
    801. rocksdb_merge_combine_read_size
    802. rocksdb_merge_tmp_file_removal_delay_ms
    803. rocksdb_new_table_reader_for_compaction_inputs
    804. rocksdb_no_block_cache
    805. rocksdb_override_cf_options
    806. rocksdb_paranoid_checks
    807. rocksdb_pause_background_work
    808. rocksdb_perf_context_level
    809. rocksdb_persistent_cache_path
    810. rocksdb_persistent_cache_size_mb
    811. rocksdb_pin_l0_filter_and_index_blocks_in_cache
    812. rocksdb_print_snapshot_conflict_queries
    813. rocksdb_rate_limiter_bytes_per_sec
    814. rocksdb_read_free_rpl_tables
    815. rocksdb_records_in_range
    816. rocksdb_remove_mariabackup_checkpoint
    817. rocksdb_reset_stats
    818. rocksdb_rollback_on_timeout
    819. rocksdb_seconds_between_stat_computes
    820. rocksdb_signal_drop_index_thread
    821. rocksdb_sim_cache_size
    822. rocksdb_skip_bloom_filter_on_read
    823. rocksdb_skip_fill_cache
    824. rocksdb_skip_unique_check_tables
    825. rocksdb-sst-mgr-rate-bytes-per-sec
    826. rocksdb_stats_dump_period_sec
    827. rocksdb_stats_level
    828. rocksdb_stats_recalc_rate
    829. rocksdb_store_row_debug_checksums
    830. rocksdb_strict_collation_check
    831. rocksdb_strict_collation_exceptions
    832. rocksdb_supported_compression_types
    833. rocksdb_table_cache_numshardbits
    834. rocksdb_table_stats_sampling_pct
    835. rocksdb_tmpdir
    836. rocksdb_trace_sst_api
    837. rocksdb_two_write_queues
    838. rocksdb_unsafe_for_binlog
    839. rocksdb_update_cf_options
    840. rocksdb_use_adaptive_mutex
    841. rocksdb_use_clock_cache
    842. rocksdb_use_direct_io_for_flush_and_compaction
    843. rocksdb_use_direct_reads
    844. rocksdb_use_fsync
    845. rocksdb_validate_tables
    846. rocksdb_verify_row_debug_checksums
    847. rocksdb_wal_bytes_per_sync
    848. rocksdb_wal_dir
    849. rocksdb_wal_recovery_mode
    850. rocksdb_wal_size_limit_mb
    851. rocksdb_wal_ttl_seconds
    852. rocksdb_whole_key_filtering
    853. rocksdb_write_batch_max_bytes
    854. rocksdb_write_disable_wal
    855. rocksdb_write_ignore_missing_column_families
    856. rocksdb_write_policy
    857. rowid_merge_buff_size
    858. rpl_recovery_rank
    859. rpl_semi_sync_master_enabled
    860. rpl_semi_sync_master_timeout
    861. rpl_semi_sync_master_trace_level
    862. rpl_semi_sync_master_wait_no_slave
    863. rpl_semi_sync_master_wait_point
    864. rpl_semi_sync_slave_delay_master
    865. rpl_semi_sync_slave_enabled
    866. rpl_semi_sync_slave_kill_conn_timeout
    867. rpl_semi_sync_slave_trace_level
    868. s3_access_key
    869. s3_block_size
    870. s3_bucket
    871. s3_debug
    872. s3_host_name
    873. s3_pagecache_age_threshold
    874. s3_pagecache_buffer_size
    875. s3_pagecache_division_limit
    876. s3_pagecache_file_hash_size
    877. s3_port
    878. s3_protocol_version
    879. s3_region
    880. s3_secret_key
    881. s3_slave_ignore_updates
    882. s3_use_http
    883. safe_show_database
    884. secure_auth
    885. secure_file_priv
    886. secure_timestamp
    887. server_audit_events
    888. server_audit_excl_users
    889. server_audit_file_path
    890. server_audit_file_rotate_now
    891. server_audit_file_rotate_size
    892. server_audit_file_rotations
    893. server_audit_incl_users
    894. server_audit_loc_info
    895. server_audit_logging
    896. server_audit_mode
    897. server_audit_output_type
    898. server_audit_query_limit
    899. server_audit_syslog_facility
    900. server_audit_syslog_ident
    901. server_audit_syslog_info
    902. server_audit_syslog_priority
    903. server_id
    904. session_track_schema
    905. session_track_state_change
    906. session_track_system_variables
    907. session_track_transaction_info
    908. shared_memory
    909. shared_memory_base_name
    910. simple_password_check_digits
    911. simple_password_check_letters_same_case
    912. simple_password_check_minimal_length
    913. simple_password_check_other_characters
    914. skip_external_locking
    915. skip_grant_tables
    916. skip_name_resolve
    917. skip_networking
    918. skip_parallel_replication
    919. skip_replication
    920. skip_show_database
    921. slave_compressed_protocol
    922. slave_connections_needed_for_purge
    923. slave_ddl_exec_mode
    924. slave_domain_parallel_threads
    925. slave_exec_mode
    926. slave_load_tmpdir
    927. slave_max_allowed_packet
    928. slave_max_statement_time
    929. slave_net_timeout
    930. slave_parallel_max_queued
    931. slave_parallel_mode
    932. slave_parallel_threads
    933. slave_parallel_workers
    934. slave_run_triggers_for_rbr
    935. slave_skip_errors
    936. slave_sql_verify_checksum
    937. slave_transaction_retries
    938. slave_transaction_retry_errors
    939. slave_transaction_retry_interval
    940. slave_type_conversions
    941. slow_launch_time
    942. slow_query_log
    943. slow_query_log_file
    944. socket
    945. sort_buffer_size
    946. spider_auto_increment_mode
    947. spider_auto_increment_mode
    948. spider_auto_increment_mode
    949. spider_bgs_second_read
    950. spider_bka_engine
    951. spider_bka_mode
    952. spider_block_size
    953. spider_buffer_size
    954. spider_bulk_size
    955. spider_bulk_update_mode
    956. spider_bulk_update_size
    957. spider_casual_read
    958. spider_conn_recycle_mode
    959. spider_conn_recycle_strict
    960. spider_conn_wait_timeout
    961. spider_connect_error_interval
    962. spider_connect_mutex
    963. spider_connect_retry_count
    964. spider_connect_retry_interval
    965. spider_connect_timeout
    966. spider_crd_bg_mode
    967. spider_crd_interval
    968. spider_crd_mode
    969. spider_crd_sync
    970. spider_crd_type
    971. spider_crd_weight
    972. spider_delete_all_rows_type
    973. spider_direct_dup_insert
    974. spider_direct_order_limit
    975. spider_dry_access
    976. spider_error_read_mode
    977. spider_error_write_mode
    978. spider_first_read
    979. spider_force_commit
    980. spider_general_log
    981. spider_ignore_comments
    982. spider_index_hint_pushdown
    983. spider_init_sql_alloc_size
    984. spider_internal_limit
    985. spider_internal_offset
    986. spider_internal_optimize
    987. spider_internal_optimize_local
    988. spider_internal_sql_log_off
    989. spider_internal_unlock
    990. spider_internal_xa
    991. spider_internal_xa_id_type
    992. spider_internal_xa_snapshot
    993. spider_load_crd_at_startup
    994. spider_load_sts_at_startup
    995. spider_local_lock_table
    996. spider_lock_exchange
    997. spider_log_result_error_with_sql
    998. spider_log_result_errors
    999. spider_low_mem_read
    1000. spider_max_connections
    1001. spider_max_order
    1002. spider_multi_split_read
    1003. spider_net_read_timeout
    1004. spider_net_write_timeout
    1005. spider_ping_interval_at_trx_start
    1006. spider_quick_mode
    1007. spider_quick_page_byte
    1008. spider_quick_page_size
    1009. spider_read_only_mode
    1010. spider_remote_access_charset
    1011. spider_remote_autocommit
    1012. spider_remote_default_database
    1013. spider_remote_sql_log_off
    1014. spider_remote_time_zone
    1015. spider_remote_trx_isolation
    1016. spider_remote_wait_timeout
    1017. spider_reset_sql_alloc
    1018. spider_same_server_link
    1019. spider_second_read
    1020. spider_select_column_mode
    1021. spider_selupd_lock_mode
    1022. spider_semi_split_read
    1023. spider_semi_split_read_limit
    1024. spider_semi_table_lock
    1025. spider_semi_table_lock_connection
    1026. spider_semi_trx
    1027. spider_semi_trx_isolation
    1028. spider_skip_default_condition
    1029. spider_skip_parallel_search
    1030. spider_slave_trx_isolation
    1031. spider_split_read
    1032. spider_store_last_crd
    1033. spider_store_last_sts
    1034. spider_strict_group_by
    1035. spider_sts_bg_mode
    1036. spider_sts_interval
    1037. spider_sts_mode
    1038. spider_sts_sync
    1039. spider_support_xa
    1040. spider_suppress_comment_ignored_warning
    1041. spider_sync_autocommit
    1042. spider_sync_sql_mode
    1043. spider_sync_time_zone
    1044. spider_sync_trx_isolation
    1045. spider_table_crd_thread_count
    1046. spider_table_init_error_interval
    1047. spider_table_sts_thread_count
    1048. spider_udf_ct_bulk_insert_interval
    1049. spider_udf_ct_bulk_insert_rows
    1050. spider_udf_ds_bulk_insert_rows
    1051. spider_udf_ds_table_loop_mode
    1052. spider_udf_ds_use_real_table
    1053. spider_udf_table_lock_mutex_count
    1054. spider_udf_table_mon_mutex_count
    1055. spider_use_all_conns_snapshot
    1056. spider_use_cond_other_than_pk_for_update
    1057. spider_use_consistent_snapshot
    1058. spider_use_default_database
    1059. spider_use_flash_logs
    1060. spider_use_handler
    1061. spider_use_pushdown_udf
    1062. spider_use_table_charset
    1063. spider_version
    1064. spider_wait_timeout
    1065. spider_xa_register_mode
    1066. sql_auto_is_null
    1067. sql_big_selects
    1068. sql_big_tables
    1069. sql_buffer_result
    1070. sql_error_log_filename
    1071. sql_error_log_rate
    1072. sql_error_log_rotate
    1073. sql_error_log_rotations
    1074. sql_error_log_size_limit
    1075. sql_error_log_warnings
    1076. sql_if_exists
    1077. sql_log_bin
    1078. sql_log_off
    1079. sql_log_update
    1080. sql_low_priority_updates
    1081. sql_max_join_size
    1082. sql_mode
    1083. sql_notes
    1084. sql_quote_show_create
    1085. sql_safe_updates
    1086. sql_select_limit
    1087. sql_slave_skip_counter
    1088. sql_warnings
    1089. ssl_ca
    1090. ssl_capath
    1091. ssl_cert
    1092. ssl_cipher
    1093. ssl_crl
    1094. ssl_crlpath
    1095. ssl_key
    1096. storage_engine
    1097. standard_compliant_cte
    1098. stored_program_cache
    1099. strict_password_validation
    1100. sync_binlog
    1101. sync_frm
    1102. sync_master_info
    1103. sync_relay_log
    1104. sync_relay_log_info
    1105. system_time_zone
    1106. system_versioning_alter_history
    1107. system_versioning_asof
    1108. system_versioning_innodb_algorithm_simple
    1109. system_versioning_insert_history
    1110. table_definition_cache
    1111. table_lock_wait_timeout
    1112. table_open_cache
    1113. table_open_cache_instances
    1114. table_type
    1115. tcp_keepalive_interval
    1116. tcp_keepalive_probes
    1117. tcp_keepalive_time
    1118. tcp_nodelay
    1119. thread_cache_size
    1120. thread_concurrency
    1121. thread_handling
    1122. thread_pool_dedicated_listener
    1123. thread_pool_exact_stats
    1124. thread_pool_idle_timeout
    1125. thread_pool_max_threads
    1126. thread_pool_min_threads
    1127. thread_pool_oversubscribe
    1128. thread_pool_prio_kickup_timer
    1129. thread_pool_priority
    1130. thread_pool_size
    1131. thread_pool_stall_limit
    1132. thread_stack
    1133. time_format
    1134. time_zone
    1135. timed_mutexes
    1136. timestamp
    1137. tls_version
    1138. tmp_disk_table_size
    1139. tmp_memory_table_size
    1140. tmp_table_size
    1141. tmpdir
    1142. tokudb_alter_print_error
    1143. tokudb_analyze_time
    1144. tokudb_block_size
    1145. tokudb_bulk_fetch
    1146. tokudb_cache_size
    1147. tokudb_check_jemalloc
    1148. tokudb_checkpoint_lock
    1149. tokudb_checkpoint_on_flush_logs
    1150. tokudb_checkpointing_period
    1151. tokudb_cleaner_iterations
    1152. tokudb_cleaner_period
    1153. tokudb_commit_sync
    1154. tokudb_create_index_online
    1155. tokudb_data_dir
    1156. tokudb_debug
    1157. tokudb_directio
    1158. tokudb_disable_hot_alter
    1159. tokudb_disable_prefetching
    1160. tokudb_disable_slow_alter
    1161. tokudb_empty_scan
    1162. tokudb_fs_reserve_percent
    1163. tokudb_fsync_log_period
    1164. tokudb_hide_default_row_format
    1165. tokudb_killed_time
    1166. tokudb_last_lock_timeout
    1167. tokudb_load_save_space
    1168. tokudb_loader_memory_size
    1169. tokudb_lock_timeout
    1170. tokudb_lock_timeout_debug
    1171. tokudb_log_dir
    1172. tokudb_max_lock_memory
    1173. tokudb_optimize_index_fraction
    1174. tokudb_optimize_index_name
    1175. tokudb_optimize_throttle
    1176. tokudb_pk_insert_mode
    1177. tokudb_prelock_empty
    1178. tokudb_read_block_size
    1179. tokudb_read_buf_size
    1180. tokudb_read_status_frequency
    1181. tokudb_row_format
    1182. tokudb_rpl_check_readonly
    1183. tokudb_rpl_lookup_rows
    1184. tokudb_rpl_lookup_rows_delay
    1185. tokudb_rpl_unique_checks
    1186. tokudb_rpl_unique_checks_delay
    1187. tokudb_support_xa
    1188. tokudb_tmp_dir
    1189. tokudb_version
    1190. tokudb_write_status_frequency
    1191. transaction_alloc_block_size
    1192. transaction_isolation
    1193. transaction_prealloc_size
    1194. transaction_read_only
    1195. tx_isolation
    1196. tx_read_only
    1197. unique_checks
    1198. updatable_views_with_limit
    1199. use_stat_tables
    1200. userstat
    1201. version
    1202. version_comment
    1203. version_compile_machine
    1204. version_compile_os
    1205. version_malloc_library
    1206. version_source_revision
    1207. version_ssl_library
    1208. wait_timeout
    1209. warning_count
    1210. wsrep_allowlist
    1211. wsrep_auto_increment_control
    1212. wsrep_causal_reads
    1213. wsrep_certification_rules
    1214. wsrep_certify_nonPK
    1215. wsrep_cluster_address
    1216. wsrep_cluster_name
    1217. wsrep_convert_LOCK_to_trx
    1218. wsrep_data_home_dir
    1219. wsrep_dbug_option
    1220. wsrep_debug
    1221. wsrep_desync
    1222. wsrep_dirty_reads
    1223. wsrep_drupal_282555_workaround
    1224. wsrep_forced_binlog_format
    1225. wsrep_gtid_domain_id
    1226. wsrep_gtid_mode
    1227. wsrep_gtid_seq_no
    1228. wsrep_ignore_apply_errors
    1229. wsrep_load_data_splitting
    1230. wsrep_log_conflicts
    1231. wsrep_max_ws_rows
    1232. wsrep_max_ws_size
    1233. wsrep_mode
    1234. wsrep_mysql_replication_bundle
    1235. wsrep_node_address
    1236. wsrep_node_incoming_address
    1237. wsrep_node_name
    1238. wsrep_notify_cmd
    1239. wsrep_on
    1240. wsrep_OSU_method
    1241. wsrep_provider
    1242. wsrep_provider_options
    1243. wsrep_recover
    1244. wsrep_reject_queries
    1245. wsrep_replicate_myisam
    1246. wsrep_restart_slave
    1247. wsrep_retry_autocommit
    1248. wsrep_slave_FK_checks
    1249. wsrep_slave_threads
    1250. wsrep_slave_UK_checks
    1251. wsrep_sr_store
    1252. wsrep_sst_auth
    1253. wsrep_sst_donor
    1254. wsrep_sst_donor_rejects_queries
    1255. wsrep_sst_method
    1256. wsrep_sst_receive_address
    1257. wsrep_start_position
    1258. wsrep_status_file
    1259. wsrep_strict_ddl
    1260. wsrep_sync_wait
    1261. wsrep_trx_fragment_size
    1262. wsrep_trx_fragment_unit

About the Server System Variables

MariaDB has many system variables that can be changed to suit your needs.

The full list of server variables are listed in the contents on this page, and most are described on this page, but some are described elsewhere:

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

Most of these can be set with command line options and many of them can be changed at runtime. Variables that can be changed at runtime (and therefore are not read-only) are described as "Dynamic" below, and elsewhere in the documentation.

There are a few ways to see the full list of server system variables:

  • While in the mariadb client, run:
SHOW VARIABLES;
  • From your shell, run mariadbd like so:
mariadbd --verbose --help

Setting Server System Variables

There are several ways to set server system variables:

  • Specify them on the command line:
shell> ./mysqld_safe --aria_group_commit="hard"
aria_group_commit = "hard"
  • Set them from the mariadb client using the SET command. Only variables that are dynamic can be set at runtime in this way. Note that variables set in this way will not persist after a restart.
SET GLOBAL aria_group_commit="hard";

By convention, server variables have usually been specified with an underscore in the configuration files, and a dash on the command line. You can however specify underscores as dashes - they are interchangeable.

Variables that take a numeric size can either be specified in full, or with a suffix for easier readability. Valid suffixes are:

SuffixDescriptionValue
Kkilobytes1024
Mmegabytes10242
Ggigabytes10243
Tterabytes10244 (from MariaDB 10.3.3)
Ppetabytes10245 (from MariaDB 10.3.3)
Eexabytes10246 (from MariaDB 10.3.3)

The suffix can be upper or lower-case.

List of Server System Variables

allow_suspicious_udfs

  • Description: Allows use of user-defined functions consisting of only one symbol x() without corresponding x_init() or x_deinit(). That also means that one can load any function from any library, for example exit() from libc.so. Not recommended unless you require old UDFs with one symbol that cannot be recompiled. Before MariaDB 10.10, available as an option only.
  • Commandline: --allow-suspicious-udfs
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF
  • Introduced: MariaDB 10.10

alter_algorithm

  • Description: The implied ALGORITHM for ALTER TABLE if no ALGORITHM clause is specified. The deprecated variable old_alter_table is an alias for this. The feature was removed in MariaDB 11.5. See ALGORITHM=DEFAULT.
    • COPY corresponds to the pre-MySQL 5.1 approach of creating an intermediate table, copying data one row at a time, and renaming and dropping tables.
    • INPLACE requests that the operation be refused if it cannot be done natively inside a the storage engine.
    • DEFAULT (the default) chooses INPLACE if available, and falls back to COPY.
    • NOCOPY refuses to copy a table.
    • INSTANT refuses an operation that would involve any other than metadata changes.
  • Commandline: --alter-algorithm=default
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumerated
  • Default Value: DEFAULT
  • Valid Values: DEFAULT, COPY, INPLACE, NOCOPY, INSTANT
  • Introduced: MariaDB 10.3.7
  • Deprecated: MariaDB 11.5

analyze_sample_percentage

  • Description: Percentage of rows from the table ANALYZE TABLE will sample to collect table statistics. Set to 0 to let MariaDB decide what percentage of rows to sample.
  • Commandline: --analyze-sample-percentage=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 100.000000
  • Range: 0 to 100
  • Introduced: MariaDB 10.4.3

autocommit

  • Description: If set to 1, the default, all queries are committed immediately. The LOCK IN SHARE MODE and FOR UPDATE clauses therefore have no effect. If set to 0, they are only committed upon a COMMIT statement, or rolled back with a ROLLBACK statement. If autocommit is set to 0, and then changed to 1, all open transactions are immediately committed.
  • Commandline: --autocommit[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

automatic_sp_privileges

  • Description: When set to 1, the default, when a stored routine is created, the creator is automatically granted permission to ALTER (which includes dropping) and to EXECUTE the routine. If set to 0, the creator is not automatically granted these privileges.
  • Commandline: --automatic-sp-privileges, --skip-automatic-sp-privileges
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

back_log

  • Description: Connections take a small amount of time to start, and this setting determines the number of outstanding connection requests MariaDB can have, or the size of the listen queue for incoming TCP/IP requests. Requests beyond this will be refused. Increase if you expect short bursts of connections. Cannot be set higher than the operating system limit (see the Unix listen() man page). If not set, set to 0, or the --autoset-back-log option is used, will be autoset to the lower of 900 and (50 + max_connections/5).
  • Commandline: --back-log=#
  • Scope: Global
  • Dynamic: No
  • Type: number
  • Default Value:

basedir

  • Description: Path to the MariaDB installation directory. Other paths are usually resolved relative to this base directory.
  • Commandline: --basedir=path or -b path
  • Scope: Global
  • Dynamic: No
  • Type: directory name

big_tables

  • Description: If this system variable is set to 1, then temporary tables will be saved to disk intead of memory.
    • This system variable's original intention was to allow result sets that were too big for memory-based temporary tables and to avoid the resulting 'table full' errors.
    • This system variable is no longer needed, because the server can automatically convert large memory-based temporary tables into disk-based temporary tables when they exceed the value of the tmp_memory_table_size system variable.
    • To prevent memory-based temporary tables from being used at all, set the tmp_memory_table_size system variable to 0.
    • In MariaDB 5.5 and earlier, sql_big_tables is a synonym.
    • In MariaDB 10.5, this system variable is deprecated.
  • Commandline: --big-tables
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0
  • Deprecated: MariaDB 10.5.0

bind_address

  • Description: By default, the MariaDB server listens for TCP/IP connections on all addresses. You can specify an alternative when the server starts using this option; either a host name, an IPv4 or an IPv6 address, "::" or "*" (all addresses). In some systems, such as Debian and Ubuntu, the bind_address is set to 127.0.0.1, which binds the server to listen on localhost only. bind_address has always been available as a mariadbd option; from MariaDB 10.3.3 its also available as a system variable. Before MariaDB 10.6.0 "::" implied listening additionally on IPv4 addresses like "*". From 10.6.0 onwards it refers to IPv6 stictly. Starting with MariaDB 10.11, a comma-separated list of addresses to bind to can be given. See also Configuring MariaDB for Remote Client Access.
  • Commandline: --bind-address=addr
  • Scope: Global
  • Dynamic: No
  • Data Type: string
  • Default Value: (Empty string)
  • Valid Values: Host name, IPv4, IPv6, ::, *
  • Introduced: MariaDB 10.3.3 (as a system variable)

block_encryption_mode

  • Description: Default block encryption mode for AES_ENCRYPT() and AES_DECRYPT() functions.
  • Commandline: --block-encryption-mode=val
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: aes-128-ecb
  • Valid values: aes-128-ecb, aes-192-ecb, aes-256-ecb, aes-128-cbc, aes-192-cbc, aes-256-cbc, aes-128-ctr, aes-192-ctr, aes-256-ctr
  • Introduced: MariaDB 11.2.0

bulk_insert_buffer_size

  • Description: Size in bytes of the per-thread cache tree used to speed up bulk inserts into MyISAM and Aria tables. A value of 0 disables the cache tree.
  • Commandline: --bulk-insert-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 8388608
  • Range - 32 bit: 0 to 4294967295
  • Range - 64 bit: 0 to 18446744073709547520

character_set_client

  • Description: Determines the character set for queries arriving from the client. It can be set per session by the client, although the server can be configured to ignore client requests with the --skip-character-set-client-handshake option. If the client does not request a character set, or requests a character set that the server does not support, the global value will be used. utf16, utf16le, utf32 and ucs2 cannot be used as client character sets. From MariaDB 10.6, the utf8 character set (and related collations) is by default an alias for utf8mb3 rather than the other way around. It can be set to imply utf8mb4 by changing the value of the old_mode system variable.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: utf8mb3 (>= MariaDB 10.6), utf8 (<= MariaDB 10.5)

character_set_collations

  • Description: Overrides for character set default collations. Takes a comma-delimited list of character set and collation settings, for example SET @@character_set_collations = 'utf8mb4=uca1400_ai_ci, latin2=latin2_hungarian_ci'; The new variable will take effect in all cases where a character set is explicitly or implicitly specified without an explicit COLLATE clause, including but not limited to:
    • Column collation
    • Table collation
    • Database collation
    • CHAR(expr USING csname)
    • CONVERT(expr USING csname)
    • CAST(expr AS CHAR CHARACTER SET csname)
    • '' - character string literal
    • _utf8mb3'text' - a character string literal with an introducer
    • _utf8mb3 X'61' - a character string literal with an introducer with hex notation
    • _utf8mb3 0x61 - a character string literal with an introducer with hex hybrid notation
    • @@collation_connection after a SET NAMES without COLLATE
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: Empty
  • Introduced: MariaDB 11.2

character_set_connection

  • Description: Character set used for number to string conversion, as well as for literals that don't have a character set introducer. From MariaDB 10.6, the utf8 character set (and related collations) is by default an alias for utf8mb3 rather than the other way around. It can be set to imply utf8mb4 by changing the value of the old_mode system variable.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: utf8mb3 (>= MariaDB 10.6), utf8 (<= MariaDB 10.5)

character_set_database

  • Description: Character set used by the default database, and set by the server whenever the default database is changed. If there's no default database, character_set_database contains the same value as character_set_server. This variable is dynamic, but should not be set manually, only by the server.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: latin1

character_set_filesystem

  • Description: The character set for the filesystem. Used for converting file names specified as a string literal from character_set_client to character_set_filesystem before opening the file. By default set to binary, so no conversion takes place. This could be useful for statements such as LOAD_FILE() or LOAD DATA INFILE on system where multi-byte file names are use.
  • Commandline: --character-set-filesystem=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: binary

character_set_results

  • Description: Character set used for results and error messages returned to the client. From MariaDB 10.6, the utf8 character set (and related collations) is by default an alias for utf8mb3 rather than the other way around. It can be set to imply utf8mb4 by changing the value of the old_mode system variable.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: utf8mb3 (>= MariaDB 10.6), utf8 (<= MariaDB 10.5)

character_set_server

  • Description: Default character set used by the server. See character_set_database for character sets used by the default database. Defaults may be different on some systems, see for example Differences in MariaDB in Debian.
  • Commandline: --character-set-server
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: latin1

character_set_system

  • Description: Character set used by the server to store identifiers, always set to utf8, or its synonym utf8mb3 starting with MariaDB 10.6. From MariaDB 10.6, the utf8 character set (and related collations) is by default an alias for utf8mb3 rather than the other way around. It can be set to imply utf8mb4 by changing the value of the old_mode system variable.
  • Scope: Global
  • Dynamic: No
  • Data Type: string
  • Default Value: utf8mb3 (>= MariaDB 10.6), utf8 (<= MariaDB 10.5)

character_sets_dir

  • Description: Directory where the character sets are installed.
  • Commandline: --character-sets-dir=path
  • Scope: Global
  • Dynamic: No
  • Type: directory name

check_constraint_checks

  • Description: If set to 0, will disable constraint checks, for example when loading a table that violates some constraints that you plan to fix later.
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: boolean
  • Default: ON

collation_connection

  • Description: Collation used for the connection character set.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string

collation_database

  • Description: Collation used for the default database. Set by the server if the default database changes, if there is no default database the value from the collation_server variable is used. This variable is dynamic, but should not be set manually, only by the server.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string

collation_server

  • Description: Default collation used by the server. This is set to the default collation for a given character set automatically when character_set_server is changed, but it can also be set manually. Defaults may be different on some systems, see for example Differences in MariaDB in Debian.
  • Commandline: --collation-server=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: latin1_swedish_ci

completion_type

  • Description: The transaction completion type. If set to NO_CHAIN or 0 (the default), there is no effect on commits and rollbacks. If set to CHAIN or 1, a COMMIT statement is equivalent to COMMIT AND CHAIN, while a ROLLBACK is equivalent to ROLLBACK AND CHAIN, so a new transaction starts straight away with the same isolation level as transaction that's just finished. If set to RELEASE or 2, a COMMIT statement is equivalent to COMMIT RELEASE, while a ROLLBACK is equivalent to ROLLBACK RELEASE, so the server will disconnect after the transaction completes. Note that the transaction completion type only applies to explicit commits, not implicit commits.
  • Commandline: --completion-type=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumerated
  • Default Value: NO_CHAIN
  • Valid Values: 0, 1, 2, NO_CHAIN, CHAIN, RELEASE

concurrent_insert

  • Description: If set to AUTO or 1, the default, MariaDB allows concurrent INSERTs and SELECTs for MyISAM tables with no free blocks in the data (deleted rows in the middle). If set to NEVER or 0, concurrent inserts are disabled. If set to ALWAYS or 2, concurrent inserts are permitted for all MyISAM tables, even those with holes, in which case new rows are added at the end of a table if the table is being used by another thread.

    If the --skip-new option is used when starting the server, concurrent_insert is set to NEVER.

    Changing the variable only affects new opened tables. Use FLUSH TABLES If you want it to also affect cached tables.

    See Concurrent Inserts for more.
  • Commandline: --concurrent-insert[=value]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: enumerated
  • Default Value: AUTO
  • Valid Values: 0, 1, 2, AUTO, NEVER, ALWAYS

connect_timeout

  • Description: Time in seconds that the server waits for a connect packet before returning a 'Bad handshake'. Increasing may help if clients regularly encounter 'Lost connection to MySQL server at 'X', system error: error_number' type-errors.
  • Commandline: --connect-timeout=#
  • Scope: Global
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 10

core_file

  • Description: Write a core-file on crashes. The file name and location are system dependent. On Linux it is usually called core.${PID}, and it is usually written to the data directory. However, this can be changed.
  • Commandline: --core-file
  • Scope: Global
  • Dynamic: No
  • Type: boolean
  • Default Value:

datadir

  • Description: Directory where the data is stored.
  • Commandline: --datadir=path or -h path
  • Scope: Global
  • Dynamic: No
  • Type: directory name

date_format


datetime_format


debug/debug_dbug

  • Description: Available in debug builds only (built with -DWITH_DEBUG=1). Used in debugging through the DBUG library to write to a trace file. Just using --debug will write a trace of what mariadbd is doing to the default trace file.
  • Commandline: -#, --debug[=debug_options]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value:
    • <= MariaDB 10.4: d:t:i:o,/tmp/mysqld.trace (Unix) or d:t:i:O,\mysqld.trace (Windows)
    • >= MariaDB 10.5: d:t:i:o,/tmp/mariadbd.trace (Unix) or d:t:i:O,\mariadbd.trace (Windows)
  • Debug Options: See the option flags on the mysql_debug page

debug_no_thread_alarm

  • Description: Disable system thread alarm calls. Disabling it may be useful in debugging or testing, never do it in production.
  • Commandline: --debug-no-thead-alarm=#
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

debug_sync

  • Description: Used in debugging to show the interface to the Debug Sync facility. MariaDB needs to be configured with -DENABLE_DEBUG_SYNC=1 for this variable to be available.
  • Scope: Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: OFF or ON - current signal signal name

default_password_lifetime

  • Description: This defines the global password expiration policy. 0 means automatic password expiration is disabled. If the value is a positive integer N, the passwords must be changed every N days. This behavior can be overridden using the password expiration options in ALTER USER.
  • Commandline: --default-password-lifetime=#
  • Scope: Global
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 0
  • Range: 0 to 4294967295
  • Introduced: MariaDB 10.4.3

default_regex_flags

  • Description: Introduced to address remaining incompatibilities between PCRE and the old regex library. Accepts a comma-separated list of zero or more of the following values:
ValuePattern equivalentMeaning
DOTALL(?s). matches anything including NL
DUPNAMES(?J)Allow duplicate names for subpatterns
EXTENDED(?x)Ignore white space and # comments
EXTRA(?X)extra features (e.g. error on unknown escape character)
MULTILINE(?m)^ and $ match newlines within data
UNGREEDY(?U)Invert greediness of quantifiers
  • Commandline: --default-regex-flags=value
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: enumeration
  • Default Value: empty
  • Valid Values: DOTALL, DUPNAMES, EXTENDED, EXTRA, MULTILINE, UNGREEDY

default_storage_engine

  • Description: The default storage engine. The default storage engine must be enabled at server startup or the server won't start.
  • Commandline: --default-storage-engine=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: enumeration
  • Default Value: InnoDB

default_table_type


default_tmp_storage_engine

  • Description: Default storage engine that will be used for tables created with CREATE TEMPORARY TABLE where no engine is specified. For internal temporary tables see aria_used_for_temp_tables). The storage engine used must be active or the server will not start. See default_storage_engine for the default for non-temporary tables. Defaults to NULL, in which case the value from default_storage_engine is used. ROCKSDB temporary tables cannot be created. Before MariaDB 10.7, attempting to do so would silently fail, and a MyISAM table would instead be created. From MariaDB 10.7, an error is returned.
  • Commandline: --default-tmp-storage-engine=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value: NULL

default_week_format

  • Description: Default mode for the WEEK() function. See that page for details on the different modes
  • Commandline: --default-week-format=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0 to 7

delay_key_write

  • Description: Specifies how MyISAM tables handles CREATE TABLE DELAY_KEY_WRITE. If set to ON, the default, any DELAY KEY WRITEs are honored. The key buffer is then flushed only when the table closes, speeding up writes. MyISAM tables should be automatically checked upon startup in this case, and --external locking should not be used, as it can lead to index corruption. If set to OFF, DELAY KEY WRITEs are ignored, while if set to ALL, all new opened tables are treated as if created with DELAY KEY WRITEs enabled.
  • Commandline: --delay-key-write[=name]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value: ON
  • Valid Values: ON, OFF, ALL

delayed_insert_limit

  • Description: After this many rows have been inserted with INSERT DELAYED, the handler will check for and execute any waiting SELECT statements.
  • Commandline: --delayed-insert-limit=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 100
  • Range: 1 to 4294967295

delayed_insert_timeout

  • Description: Time in seconds that the INSERT DELAYED handler will wait for INSERTs before terminating.
  • Commandline: --delayed-insert-timeout=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 300

delayed_queue_size

  • Description: Number of rows, per table, that can be queued when performing INSERT DELAYED statements. If the queue becomes full, clients attempting to perform INSERT DELAYED's will wait until the queue has room available again.
  • Commandline: --delayed-queue-size=#
  • Scope: Global
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 1000
  • Range: 1 to 4294967295

disconnect_on_expired_password

  • Description: When a user password has expired (see User Password Expiry), this variable controls how the server handles clients that are not aware of the sandbox mode. If enabled, the client is not permitted to connect, otherwise the server puts the client in a sandbox mode.
  • Commandline: --disconnect-on-expired-password[={0|1}]
  • Scope: Global
  • Dynamic: Yes
  • Type: boolean
  • Default Value: OFF
  • Introduced: MariaDB 10.4.3

div_precision_increment

  • Description: The precision of the result of the decimal division will be the larger than the precision of the dividend by that number. By default it's 4, so SELECT 2/15 would return 0.1333 and SELECT 2.0/15 would return 0.13333. After setting div_precision_increment to 6, for example, the same operation would return 0.133333 and 0.1333333 respectively.

From MariaDB 10.1.46, MariaDB 10.2.33, MariaDB 10.3.24, MariaDB 10.4.14 and MariaDB 10.5.5, div_precision_increment is taken into account in intermediate calculations. Previous versions did not, and the results were dependent on the optimizer, and therefore unpredictable.

In MariaDB 10.1.46, MariaDB 10.1.47, MariaDB 10.2.33, MariaDB 10.2.34, MariaDB 10.2.35, MariaDB 10.3.24, MariaDB 10.3.25, MariaDB 10.4.14, MariaDB 10.4.15, MariaDB 10.5.5 and MariaDB 10.5.6 only, the fix truncated decimal values after every division, resulting in lower precision in some cases for those versions only.

From MariaDB 10.1.48, MariaDB 10.2.35, MariaDB 10.3.26, MariaDB 10.4.16 and MariaDB 10.5.7, a different fix was implemented. Instead of truncating decimal values after every division, they are instead truncated for comparison purposes only.

For example

SELECT (55/23244*1000);
+-----------------+
| (55/23244*1000) |
+-----------------+
|          2.3662 |
+-----------------
SELECT (55/23244*1000);
+-----------------+
| (55/23244*1000) |
+-----------------+
|          2.4000 |
+-----------------+

This is because the intermediate result, SELECT 55/23244 takes into account div_precision_increment and results were truncated after every division in those versions only.

  • Commandline: --div-precision-increment=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4
  • Range: 0 to 30

encrypt_tmp_disk_tables


encrypt_tmp_files

  • Description: Enables automatic encryption of temporary files, such as those created for filesort operations, binary log file caches, etc. See Data at Rest Encryption.
  • Commandline: --encrypt-tmp-files[={0|1}]
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

encryption_algorithm

  • Description: Which encryption algorithm to use for table encryption. aes_cbc is the recommended one. See Table and Tablespace Encryption.
  • Commandline: --encryption-algorithm=value
  • Scope: Global
  • Dynamic: No
  • Data Type: enum
  • Default Value: none
  • Valid Values: none, aes_ecb, aes_cbc, aes_ctr
  • Introduced: MariaDB 10.1.3
  • Removed: MariaDB 10.1.4

enforce_storage_engine

  • Description: Force the use of a particular storage engine for new tables. Used to avoid unwanted creation of tables using another engine. For example, setting to InnoDB will prevent any MyISAM tables from being created. If another engine is specified in a CREATE TABLE statement, the outcome depends on whether the NO_ENGINE_SUBSTITUTION SQL_MODE has been set or not. If set, the query will fail, while if not set, a warning will be returned and the table created according to the engine specified by this variable. The variable has a session scope, but is only modifiable by a user with the SUPER privilege.
  • Commandline: None
  • Scope: Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: none

engine_condition_pushdown

  • Description: Deprecated in MariaDB 5.5 and removed and replaced by the optimizer_switch engine_condition_pushdown={on|off} flag in MariaDB 10.0.. Specifies whether the engine condition pushdown optimization is enabled. Since MariaDB 10.1.1, engine condition pushdown is enabled for all engines that support it.
  • Commandline: --engine-condition-pushdown
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Deprecated: MariaDB 5.5
  • Removed: MariaDB 10.0

eq_range_index_dive_limit

  • Description: Limit used for speeding up queries listed by long nested INs. The optimizer will use existing index statistics instead of doing index dives for equality ranges if the number of equality ranges for the index is larger than or equal to this number. If set to 0 (unlimited, the default), index dives are always used.
  • Commandline: --eq-range-index-dive-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 200 (>= MariaDB 10.4.3), 0 (<= MariaDB 10.4.2)
  • Range: 0 to 4294967295

error_count

  • Description: Read-only variable denoting the number of errors from the most recent statement in the current session that generated errors. See SHOW_ERRORS().
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric

event_scheduler

  • Description: Status of the Event Scheduler. Can be set to ON or OFF, while DISABLED means it cannot be set at runtime. Setting the variable will cause a load of events if they were not loaded at startup.
  • Commandline: --event-scheduler[=value]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value: OFF
  • Valid Values: ON (or 1), OFF (or 0), DISABLED

expensive_subquery_limit

  • Description: Number of rows to be examined for a query to be considered expensive, that is, maximum number of rows a subquery may examine in order to be executed during optimization and used for constant optimization.
  • Commandline: --expensive-subquery-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 100
  • Range: 0 upwards

explicit_defaults_for_timestamp


external_user

  • Description: External user name set by the plugin used to authenticate the client. NULL if native MariaDB authentication is used.
  • Scope: Session
  • Dynamic: No
  • Data Type: string
  • Default Value: NULL

flush

  • Description: Usually, MariaDB writes changes to disk after each SQL statement, and the operating system handles synchronizing (flushing) it to disk. If set to ON, the server will synchronize all changes to disk after each statement.
  • Commandline: --flush
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

flush_time

  • Description: Interval in seconds that tables are closed to synchronize (flush) data to disk and free up resources. If set to 0, the default, there is no automatic synchronizing tables and closing of tables. This option should not be necessary on systems with sufficient resources.
  • Commandline: --flush_time=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0

foreign_key_checks

  • Description: If set to 1 (the default) foreign key constraints (including ON UPDATE and ON DELETE behavior) InnoDB tables are checked, while if set to 0, they are not checked. 0 is not recommended for normal use, though it can be useful in situations where you know the data is consistent, but want to reload data in a different order from that that specified by parent/child relationships. Setting this variable to 1 does not retrospectively check for inconsistencies introduced while set to 0.
  • Commandline: None
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

ft_boolean_syntax

  • Description: List of operators supported by an IN BOOLEAN MODE full-text search. If you wish to change, note that each character must be ASCII and non-alphanumeric, the full string must be 14 characters and the first or second character must be a space. Positions 10, 13 and 14 are reserved for future extensions. Also, no duplicates are permitted except for the phrase quoting characters in positions 11 and 12, which may be the same.
  • Commandline: --ft-boolean-syntax=name
  • Scope: Global
  • Dynamic: Yes
  • Data Type: string
  • Default Value: + -><()*:""&|

ft_max_word_len

  • Description: Maximum length for a word to be included in the MyISAM full-text index. If this variable is changed, the full-text index must be rebuilt in order for the new value to take effect. The quickest way to do this is by issuing a REPAIR TABLE table_name QUICK statement. See innodb_ft_max_token_size for the InnoDB equivalent.
  • Commandline: --ft-max-word-len=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 84
  • Minimum Value: 10

ft_min_word_len

  • Description: Minimum length for a word to be included in the MyISAM full-text index. If this variable is changed, the full-text index must be rebuilt in order for the new value to take effect. The quickest way to do this is by issuing a REPAIR TABLE table_name QUICK statement. See innodb_ft_min_token_size for the InnoDB equivalent.
  • Commandline: --ft-min-word-len=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 4
  • Minimum Value: 1

ft_query_expansion_limit

  • Description: For full-text searches, denotes the numer of top matches when using WITH QUERY EXPANSION.
  • Commandline: --ft-query-expansion-limit=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 20
  • Range: 0 to 1000

ft_stopword_file

  • Description: File containing a list of stopwords for use in MyISAM full-text searches. Unless an absolute path is specified the file will be looked for in the data directory. The file is not parsed for comments, so all words found become stopwords. By default, a built-in list of words (built from storage/myisam/ft_static.c file) is used. Stopwords can be disabled by setting this variable to '' (an empty string). If this variable is changed, the full-text index must be rebuilt. The quickest way to do this is by issuing a REPAIR TABLE table_name QUICK statement. See innodb_ft_server_stopword_table for the InnoDB equivalent.
  • Commandline: --ft-stopword-file=file_name
  • Scope: Global
  • Dynamic: No
  • Data Type: file name
  • Default Value: (built-in)

general_log

  • Description: If set to 0, the default unless the --general-log option is used, the general query log is disabled, while if set to 1, the general query log is enabled. See log_output for how log files are written. If that variable is set to NONE, no logs will be written even if general_query_log is set to 1.
  • Commandline: --general-log
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0

general_log_file

  • Description: Name of the general query log file. If this is not specified, the name is taken from the log-basename setting or from your system hostname with .log as a suffix.
  • Commandline: --general-log-file=file_name
  • Scope: Global
  • Dynamic: Yes
  • Data Type: file name
  • Default Value: host_name.log

group_concat_max_len

  • Description: Maximum length in bytes of the returned result for the functions GROUP_CONCAT(), JSON_OBJECTAGG and JSON_ARRAYAGG.
  • Commandline: --group-concat-max-len=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value:
    • 1048576 (1M)
  • Range: 4 to 4294967295

.

have_compress

  • Description: If the zlib compression library is accessible to the server, this will be set to YES, otherwise it will be NO. The COMPRESS() and UNCOMPRESS() functions will only be available if set to YES.
  • Scope: Global
  • Dynamic: No

have_crypt

  • Description: If the crypt() system call is available this variable will be set to YES, otherwise it will be set to NO. If set to NO, the ENCRYPT() function cannot be used.
  • Scope: Global
  • Dynamic: No

have_csv


have_dynamic_loading

  • Description: If the server supports dynamic loading of plugins, will be set to YES, otherwise will be set to NO.
  • Scope: Global
  • Dynamic: No

have_geometry

  • Description: If the server supports spatial data types, will be set to YES, otherwise will be set to NO.
  • Scope: Global
  • Dynamic: No

have_ndbcluster


have_partitioning

  • Description: If the server supports partitioning, will be set to YES, unless the --skip-partition option is used, in which case will be set to DISABLED. Will be set to NO otherwise. Removed in MariaDB 10.0 - SHOW PLUGINS should be used instead.
  • Scope: Global
  • Dynamic: No
  • Removed: MariaDB 10.0

have_profiling

  • Description: If statement profiling is available, will be set to YES, otherwise will be set to NO. See SHOW PROFILES() and SHOW PROFILE().
  • Scope: Global
  • Dynamic: No

have_query_cache

  • Description: If the server supports the query cache, will be set to YES, otherwise will be set to NO.
  • Scope: Global
  • Dynamic: No

have_rtree_keys

  • Description: If RTREE indexes (used for spatial indexes) are available, will be set to YES, otherwise will be set to NO.
  • Scope: Global
  • Dynamic: No

  • Description: This system variable can be used to determine whether the server supports symbolic links (note that it has no meaning on Windows).
    • If symbolic links are supported, then the value will be YES.
    • If symbolic links are not supported, then the value will be NO.
    • If symbolic links are disabled with the --symbolic-links option and the skip option prefix (i.e. --skip-symbolic-links), then the value will be DISABLED.
    • Symbolic link support is required for the INDEX DIRECTORY and DATA DIRECTORY table options.
  • Scope: Global
  • Dynamic: No

histogram_size


histogram_type

  • Description: Specifies the type of histograms created by ANALYZE.
    • SINGLE_PREC_HB - single precision height-balanced.
    • DOUBLE_PREC_HB - double precision height-balanced.
    • JSON_HB - JSON histograms (from MariaDB 10.7)
  • Commandline: --histogram-type=value
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value:
  • Valid Values:

host_cache_size

  • Description: Number of host names that will be cached to avoid resolving. Setting to 0 disables the cache. Changing the value while the server is running causes an implicit FLUSH HOSTS, clearing the host cache and truncating the performance_schema.host_cache table. If you are connecting from a lot of different machines you should consider increasing.
  • Commandline: --host-cache-size=#.
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 128
  • Range: 0 to 65536

hostname

  • Description: When the server starts, this variable is set to the server host name.
  • Scope: Global
  • Dynamic: No
  • Data Type: string

identity


idle_readonly_transaction_timeout


idle_transaction_timeout


idle_write_transaction_timeout


ignore_db_dirs

  • Description: Tells the server that this directory can never be a database. That means two things - firstly it is ignored by the SHOW DATABASES command and INFORMATION_SCHEMA tables. And secondly, USE, CREATE DATABASE and SELECT statements will return an error if the database from the ignored list specified. Use this option several times if you need to ignore more than one directory. To make the list empty set the void value to the option as --ignore-db-dir=. If the option or configuration is specified multiple times, viewing this value will list the ignore directories separated by commas.
  • Commandline: --ignore-db-dirs=dir.
  • Scope: Global
  • Dynamic: No
  • Data Type: string

in_predicate_conversion_threshold

  • Description: The minimum number of scalar elements in the value list of an IN predicate that triggers its conversion to an IN subquery. Set to 0 to disable the conversion. See Conversion of Big IN Predicates Into Subqueries.
  • Commandline: --in-predicate-conversion-threshold=#
  • Scope: Global, Session
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 1000
  • Range: 0 to 4294967295
  • Introduced: MariaDB 10.3.18 (previously debug builds only)

in_transaction

  • Description: Session-only and read-only variable that is set to 1 if a transaction is in progress, 0 if not.
  • Commandline: No
  • Scope: Session
  • Dynamic: No
  • Data Type: boolean
  • Default Value: 0

init_connect

  • Description: String containing one or more SQL statements, separated by semicolons, that will be executed by the server for each client connecting. If there's a syntax error in the one of the statements, the client will fail to connect. For this reason, the statements are not executed for users with the SUPER privilege or, from MariaDB 10.5.2, the CONNECTION ADMIN privilege, who can then still connect and correct the error. See also init_file.
  • Commandline: --init-connect=name
  • Scope: Global
  • Dynamic: Yes
  • Data Type: string

init_file

  • Description: Name of a file containing SQL statements that will be executed by the server on startup. Each statement should be on a new line, and end with a semicolon. See also init_connect.
  • Commandline: init-file=file_name
  • Scope: Global
  • Dynamic: No
  • Data Type: file name

insert_id

  • Description: Value to be used for the next statement inserting a new AUTO_INCREMENT value.
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric

interactive_timeout

  • Description: Time in seconds that the server waits for an interactive connection (one that connects with the mysql_real_connect() CLIENT_INTERACTIVE option) to become active before closing it. See also wait_timeout.
  • Commandline: --interactive-timeout=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 28800
  • Range: (Windows): 1 to 2147483
  • Range: (Other): 1 to 31536000

join_buffer_size

  • Description: Minimum size in bytes of the buffer used for queries that cannot use an index, and instead perform a full table scan. Increase to get faster full joins when adding indexes is not possible, although be aware of memory issues, since joins will always allocate the minimum size. Best left low globally and set high in sessions that require large full joins. In 64-bit platforms, Windows truncates values above 4GB to 4GB with a warning. See also Block-Based Join Algorithms - Size of Join Buffers.
  • Commandline: --join-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 262144 (256kB)
  • Range (non-Windows): 128 to 18446744073709547520
  • Range (Windows): 8228 to 18446744073709547520

join_buffer_space_limit

  • Description: Maximum size in bytes of the query buffer, By default 1024*128*10. See Block-based join algorithms.
  • Commandline: --join-buffer-space-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 2097152
  • Range: 2048 to 18446744073709551615

join_cache_level

  • Description: Controls which of the eight block-based algorithms can be used for join operations. See Block-based join algorithms for more information.
    • 1 – flat (Block Nested Loop) BNL
    • 2 – incremental BNL
    • 3 – flat Block Nested Loop Hash (BNLH)
    • 4 – incremental BNLH
    • 5 – flat Batch Key Access (BKA)
    • 6 – incremental BKA
    • 7 – flat Batch Key Access Hash (BKAH)
    • 8 – incremental BKAH
  • Commandline: --join-cache-level=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 2
  • Range: 0 to 8

keep_files_on_create

  • Description: If a MyISAM table is created with no DATA DIRECTORY option, the .MYD file is stored in the database directory. When set to 0, the default, if MariaDB finds another .MYD file in the database directory it will overwrite it. Setting this variable to 1 means that MariaDB will return an error instead, just as it usually does in the same situation outside of the database directory. The same applies for .MYI files and no INDEX DIRECTORY option. Deprecated in MariaDB 10.8.0.
  • Commandline: --keep-files-on-create=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Deprecated: MariaDB 10.8.0

large_files_support

  • Description: ON if the server if was compiled with large file support or not, else OFF
  • Scope: Global
  • Dynamic: No

large_page_size

  • Description: Indicates the size of memory page if large page support (Linux only) is enabled. The page size is determined from the Hugepagesize setting in /proc/meminfo. See large_pages. Deprecated and unused in MariaDB 10.5.3 since multiple page size support was added.
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: Autosized (see description)
  • Deprecated: MariaDB 10.5.3

large_pages

  • Description: Indicates whether large page support (prior to MariaDB 10.5, Linux only, by now supported Windows and BSD distros, also called huge pages) is used. This is set with --large-pages or disabled with --skip-large-pages. Large pages are used for the innodb buffer pool and for online DDL (of size 3* innodb_sort_buffer_size (or 6 when encryption is used)). To use large pages, the Linux sysctl variable kernel.shmmax must be large than the llocation. Also the sysctl variable vm.nr_hugepages multipled by large-page) must be larger than the usage. The ulimit for locked memory must be sufficient to cover the amount used (ulimit -l and equalivent in /etc/security/limits.conf / or in systemd LimitMEMLOCK). If these operating system controls or insufficient free huge pages are available, the allocation of large pages will fall back to conventional memory allocation and a warning will appear in the logs. Only allocations of the default Hugepagesize currently occur (see /proc/meminfo).
  • Commandline: --large-pages, --skip-large-pages
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

last_insert_id

  • Description: Contains the same value as that returned by LAST_INSERT_ID(). Note that setting this variable doen't update the value returned by the underlying function.
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric

lc_messages

  • Description: This system variable can be specified as a locale name. The language of the associated locale will be used for error messages. See Server Locales for a list of supported locales and their associated languages.
  • Commandline: --lc-messages=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: en_us

lc_messages_dir

  • Description: This system variable can be specified either as the path to the directory storing the server's error message files or as the path to the directory storing the specific language's error message file. See Server Locales for a list of available locales and their related languages.
  • Commandline: --lc-messages-dir=path
  • Scope: Global
  • Dynamic: No
  • Data Type: directory name

lc_time_names

  • Description: The locale that determines the language used for the date and time functions DAYNAME(), MONTHNAME() and DATE_FORMAT(). Locale names are language and region subtags, for example 'en_ZA' (English - South Africa) or 'es_US: Spanish - United States'. The default is always 'en-US' regardless of the system's locale setting. See server locale for a full list of supported locales.
  • Commandline: --lc-time-names=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: en_US

license

  • Description: Server license, for example GPL.
  • Scope: Global
  • Dynamic: No
  • Data Type: string

local_infile

  • Description: If set to 1, LOCAL is supported for LOAD DATA INFILE statements. If set to 0, usually for security reasons, attempts to perform a LOAD DATA LOCAL will fail with an error message.
  • Commandline: --local-infile=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: ON

lock_wait_timeout


locked_in_memory

  • Description: Indicates whether --memlock was used to lock mariadbd in memory.
  • Commandline: --memlock
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

log

  • Description: Deprecated and removed in MariaDB 10.0, use general_log instead.
  • Commandline: -l [filename] or --log[=filename]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: string
  • Default Value: OFF
  • Removed: MariaDB 10.0

log_disabled_statements

  • Description: If set, the specified type of statements (slave and/or stored procedure statements) will not be logged to the general log. Multiple values are comma-separated, without spaces.
  • Commandline: --log-disabled_statements=value
  • Scope: Global, Session
  • Dynamic: No
  • Data Type: set
  • Default Value: sp
  • Valid Values: slave and/or sp, or empty string for none
  • Introduced: MariaDB 10.3.1

log_error

  • Description: Specifies the name of the error log. If --console is specified later in the configuration (Windows only) or this option isn't specified, errors will be logged to stderr. If no name is provided, errors will still be logged to hostname.err in the datadir directory by default. If a configuration file sets --log-error, one can reset it with --skip-log-error (useful to override a system wide configuration file). MariaDB always writes its error log, but the destination is configurable. See error log for details.
  • Commandline: --log-error[=name], --skip-log-error
  • Scope: Global
  • Dynamic: No
  • Data Type: file name
  • Default Value: (empty string)

log_output

  • Description: How the output for the general query log and the slow query log is stored. By default written to file (FILE), it can also be stored in the general_log and slow_log tables in the mysql database (TABLE), or not stored at all (NONE). More than one option can be chosen at the same time, with NONE taking precedence if present. Logs will not be written if logging is not enabled. See Writing logs into tables, and the slow_query_log and general_log server system variables.
  • Commandline: --log-output=name
  • Scope: Global
  • Dynamic: Yes
  • Data Type: set
  • Default Value: FILE
  • Valid Values: TABLE, FILE or NONE

log_queries_not_using_indexes

  • Description: Queries that don't use an index, or that perform a full index scan where the index doesn't limit the number of rows, will be logged to the slow query log (regardless of time taken). The slow query log needs to be enabled for this to have an effect. Mapped to log_slow_filter='not_using_index' from MariaDB 10.3.1.
  • Commandline: --log-queries-not-using-indexes
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

log_slow_admin_statements


log_slow_disabled_statements


log_slow_filter

  • Description: Comma-delimited string (without spaces) containing one or more settings for filtering what is logged to the slow query log. If a query matches one of the types listed in the filter, and takes longer than long_query_time, it will be logged(except for 'not_using_index' which is always logged if enabled, regardless of the time). Sets log-slow-admin-statements to ON. See also log_slow_disabled_statements.
    • admin log administrative queries (create, optimize, drop etc...)
    • filesort logs queries that use a filesort.
    • filesort_on_disk logs queries that perform a a filesort on disk.
    • filesort_priority_queue (from MariaDB 10.3.2)
    • full_join logs queries that perform a join without indexes.
    • full_scan logs queries that perform full table scans.
    • not_using_index logs queries that don't use an index, or that perform a full index scan where the index doesn't limit the number of rows. Disregards long_query_time, unlike other options. log_queries_not_using_indexes maps to this option. From MariaDB 10.3.1.
    • query_cache log queries that are resolved by the query cache.
    • query_cache_miss logs queries that are not found in the query cache.
    • tmp_table logs queries that create an implicit temporary table.
    • tmp_table_on_disk logs queries that create a temporary table on disk.
  • Commandline: log-slow-filter=value1[,value2...]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value:
    • admin, filesort, filesort_on_disk, filesort_priority_queue, full_join, full_scan, query_cache, query_cache_miss, tmp_table, tmp_table_on_disk
  • Valid Values:
    • admin, filesort, filesort_on_disk, filesort_priority_queue, full_join, full_scan, not_using_index, query_cache, query_cache_miss, tmp_table, tmp_table_on_disk

log_slow_min_examined_row_limit

  • Description: Don't write queries to slow query log that examine fewer rows than the set value. If set to 0, the default, no row limit is used. min_examined_row_limit is an alias.
  • Commandline: --log-slow-min-examined-row-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0-4294967295
  • Introduced: MariaDB 10.11.0

log_slow_queries

  • Description: Deprecated and removed in MariaDB 10.0, use slow_query_log instead.
  • Commandline: --log-slow-queries[=name]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Removed: MariaDB 10.0

log_slow_query

  • Description: If set to 0, the default unless the --slow-query-log option is used, the slow query log is disabled, while if set to 1 (both global and session variables), the slow query log is enabled. Named slow_query_log before MariaDB 10.11.0, which is now an alias.
  • Commandline: --slow-query-log
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0
  • Introduced: MariaDB 10.11.0
  • See also: See log_output to see how log files are written. If that variable is set to NONE, no logs will be written even if log_slow_query is set to 1.

log_slow_query_file


log_slow_query_time

  • Description: If a query takes longer than this many seconds to execute (microseconds can be specified too), the Slow_queries status variable is incremented and, if enabled, the query is logged to the slow query log. Before MariaDB 10.11, was named long_query_time.
  • Commandline: --log-slow-query-time=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 10.000000
  • Range: 0 to 31536000
  • Introduced: MariaDB 10.11.0

log_slow_rate_limit

  • Description: The slow query log will log every this many queries. The default is 1, or every query, while setting it to 20 would log every 20 queries, or five percent. Aims to reduce I/O usage and excessively large slow query logs. See also Slow Query Log Extended Statistics.
  • Commandline: log-slow-rate-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1
  • Range: 1 upwards

log_slow_verbosity


log_slow_max_warnings

  • Description: Max numbers of warnings printed to slow query log per statement
  • Commandline: log-slow-max-warnings=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 10
  • Range: 0 to 1000
  • Introduced: MariaDB 10.6.16

log_tc_size

  • Description: Defines the size in bytes of the memory-mapped file-based transaction coordinator log, which is only used if the binary log is disabled. If you have two or more XA-capable storage engines enabled, then a transaction coordinator log must be available. This size is defined in multiples of 4096. See Transaction Coordinator Log for more information. Also see the --log-tc server option and the --tc-heuristic-recover option.
  • Commandline: log-tc-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 24576
  • Range: 12288 to 18446744073709551615

log_warnings

  • Description: Determines which additional warnings are logged. Setting to 0 disables additional warning logging. Note that this does not prevent all warnings, there is a core set of warnings that will always be written to the error log. The additional warnings are as follows:
    • log_warnings >= 1
      • Event scheduler information.
      • System signals
      • Wrong usage of --user
      • Failed setrlimit() and mlockall()
      • Changed limits
      • Wrong values of lower_case_table_names and stack_size
      • Wrong values for command line options
      • Start log position and some master information when starting slaves
      • Slave reconnects
      • Killed slaves
      • Error reading relay logs
      • Unsafe statements for statement-based replication. If this warning occurs frequently, it is throttled to prevent flooding the log.
      • Disabled plugins that one tried to enable or use.
      • UDF files that didn't include the required init functions.
      • DNS lookup failures.
    • log_warnings >= 2
      • Access denied errors.
      • Connections aborted or closed due to errors or timeouts.
      • Table handler errors
      • Messages related to the files used to persist replication state:
        • Either the default master.info file or the file that is configured by the master_info_file option.
        • Either the default relay-log.info file or the file that is configured by the relay_log_info_file system variable.
      • Information about a master's binary log dump thread.
    • log_warnings >= 3
    • log_warnings >=4
      • Connections aborted due to "Too many connections" errors.
      • Connections closed normally without authentication.
      • Connections aborted due to KILL.
      • Connections closed due to released connections, such as when completion_type is set to RELEASE.
      • Could not read packet: (a lot more information)
      • All read/write errors for a connection are logged to the error log.
    • log_warnings >=9
      • Information about initializing plugins.
  • Commandline: -W [level] or --log-warnings[=level]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value:
    • 2
  • Range: 0 to 4294967295

long_query_time

  • Description: If a query takes longer than this many seconds to execute (microseconds can be specified too), the Slow_queries status variable is incremented and, if enabled, the query is logged to the slow query log. From MariaDB 10.11.0, this is an alias for log_slow_query_time.
  • Commandline: --long-query-time=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 10.000000
  • Range: 0 upwards

low_priority_updates

  • Description: If set to 1 (0 is the default), for storage engines that use only table-level locking (Aria, MyISAM, MEMORY and MERGE), all INSERTs, UPDATEs, DELETEs and LOCK TABLE WRITEs will wait until there are no more SELECTs or LOCK TABLE READs pending on the relevant tables. Set this to 1 if reads are prioritized over writes.
  • Commandline: --low-priority-updates
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0

lower_case_file_system

  • Description: Read-only variable describing whether the file system is case-sensitive. If set to OFF, file names are case-sensitive. If set to ON, they are not case-sensitive.
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: ##

lower_case_table_names

  • Description: If set to 0 (the default on Unix-based systems), table names and aliases and database names are compared in a case-sensitive manner. If set to 1 (the default on Windows), names are stored in lowercase and not compared in a case-sensitive manner. If set to 2 (the default on Mac OS X), names are stored as declared, but compared in lowercase. This system variable's value cannot be changed after the datadir has been initialized. lower_case_table_names is set when a MariaDB instance starts, and it remains constant afterwards.
  • Commandline: --lower-case-table-names[=#]
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 0 (Unix), 1 (Windows), 2 (Mac OS X)
  • Range: 0 to 2

max_allowed_packet

  • Description: Maximum size in bytes of a packet or a generated/intermediate string. The packet message buffer is initialized with the value from net_buffer_length, but can grow up to max_allowed_packet bytes. Set as large as the largest BLOB, in multiples of 1024. If this value is changed, it should be changed on the client side as well. See slave_max_allowed_packet for a specific limit for replication purposes.
  • Commandline: --max-allowed-packet=#
  • Scope: Global, Session
  • Dynamic: Yes (Global), No (Session)
  • Data Type: numeric
  • Default Value:
    • 16777216 (16M)
    • 1073741824 (1GB) (client-side)
  • Range: 1024 to 1073741824

max_connect_errors

  • Description: Limit to the number of successive failed connects from a host before the host is blocked from making further connections. The count for a host is reset to zero if they successfully connect. To unblock, flush the host cache with a FLUSH HOSTS statement or mariadb-admin flush-hosts. The performance_schema.host_cache table contains the status of the current hosts.
  • Commandline: --max-connect-errors=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 100
  • Range: 1 to 4294967295

max_connections

  • Description: The maximum number of simultaneous client connections. See also Handling Too Many Connections. Note that this value affects the number of file descriptors required on the operating system. Minimum was changed from 1 to 10 to avoid possible unexpected results for the user (MDEV-18252). Note that MariaDB always has one reserved connection for a SUPER (or CONNECTION ADMIN user). Additionally it can listen on a separate port, so will be available even when the max_connections limit is reached.
  • Commandline: --max-connections=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 151
  • Range: 10 to 100000

max_delayed_threads

  • Description: Limits to the number of INSERT DELAYED threads. Once this limit is reached, the insert is handled as if there was no DELAYED attribute. If set to 0, DELAYED is ignored entirely. The session value can only be set to 0 or to the same as the global value.
  • Commandline: --max-delayed-threads=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 20
  • Range: 0 to 16384

max_digest_length

  • Description: Maximum length considered for computing a statement digest, such as used by the Performance Schema and query rewrite plugins. Statements that differ after this many bytes produce the same digest, and are aggregated for statistics purposes. The variable is allocated per session. Increasing will allow longer statements to be distinguished from each other, but increase memory use, while decreasing will reduce memory use, but more statements may become indistinguishable.
  • Commandline: --max-digest-length=#
  • Scope: Global,
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 1024
  • Range: 0 to 1048576

max_error_count

  • Description: Specifies the maximum number of messages stored for display by SHOW ERRORS and SHOW WARNINGS statements.
  • Commandline: --max-error-count=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 64
  • Range: 0 to 65535

max_heap_table_size

  • Description: Maximum size in bytes for user-created MEMORY tables. Setting the variable while the server is active has no effect on existing tables unless they are recreated or altered. The smaller of max_heap_table_size and tmp_table_size also limits internal in-memory tables. When the maximum size is reached, any further attempts to insert data will receive a "table ... is full" error. Temporary tables created with CREATE TEMPORARY will not be converted to Aria, as occurs with internal temporary tables, but will also receive a table full error.
  • Commandline: --max-heap-table-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16777216
  • Range : 16384 to 4294966272

max_insert_delayed_threads


max_join_size

  • Description: Statements will not be performed if they are likely to need to examine more than this number of rows, row combinations or do more disk seeks. Can prevent poorly-formatted queries from taking server resources. Changing this value to anything other the default will reset sql_big_selects to 0. If sql_big_selects is set again, max_join_size will be ignored. This limit is also ignored if the query result is sitting in the query cache. Previously named sql_max_join_size, which is still a synonym.
  • Commandline: --max-join-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 18446744073709551615
  • Range: 1 to 18446744073709551615

max_length_for_sort_data

  • Description: Used to decide which algorithm to choose when sorting rows. If the total size of the column data, not including columns that are part of the sort, is less than max_length_for_sort_data, then we add these to the sort key. This can speed up the sort as we don't have to re-read the same row again later. Setting the value too high can slow things down as there will be a higher disk activity for doing the sort.
  • Commandline: --max-length-for-sort-data=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1024
  • Range: 4 to 8388608

max_long_data_size


max_password_errors

  • Description: The maximum permitted number of failed connection attempts due to an invalid password before a user is blocked from further connections. FLUSH_PRIVILEGES will permit the user to connect again. This limit is ignored for users with the SUPER privilege or, from MariaDB 10.5.2, the CONNECTION ADMIN privilege. The maximum also doesn't apply to users with a hostname of localhost, 127.0.0.1 or ::1. See also the Information Schema USERS table.
  • Commandline: --max-password-errors=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4294967295
  • Range: 1 to 4294967295

max_prepared_stmt_count

  • Description: Maximum number of prepared statements on the server. Can help prevent certain forms of denial-of-service attacks. If set to 0, no prepared statements are permitted on the server.
  • Commandline: --max-prepared-stmt-count=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16382
  • Range: 0 to 4294967295 (>= MariaDB 10.3.6), 0 to 1048576 (<= MariaDB 10.3.5)

max_recursive_iterations

  • Description: Maximum number of iterations when executing recursive queries, used to prevent infinite loops in recursive CTEs.
  • Commandline: --max-recursive-iterations=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1000 (>= MariaDB 10.6.0), 4294967295 (<= MariaDB 10.5)
  • Range: 0 to 4294967295

max_rowid_filter_size

  • Description: The maximum size of the container of a rowid filter.
  • Commandline: --max-rowid-filter-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 131072
  • Range: 1024 to 18446744073709551615
  • Introduced: MariaDB 10.4.3

max_seeks_for_key

  • Description: The optimizer assumes that the number specified here is the most key seeks required when searching with an index, regardless of the actual index cardinality. If this value is set lower than its default and maximum, indexes will tend to be preferred over table scans.
  • Commandline: --max-seeks-for-key=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4294967295
  • Range: 1 to 4294967295

max_session_mem_used

  • Description: Amount of memory a single user session is allowed to allocate. This limits the value of the session variable Memory_used.
  • Commandline: --max-session-mem-used=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 9223372036854775807 (8192 PB)
  • Range: 8192 to 18446744073709551615

max_sort_length

  • Description: Maximum size in bytes used for sorting data values - anything exceeding this is ignored. The server uses only the first max_sort_length bytes of each value and ignores the rest. Increasing this may require sort_buffer_size to be increased (especially if ER_OUT_OF_SORTMEMORY errors start appearing).
  • Commandline: --max-sort-length=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1024
  • Range:

max_sp_recursion_depth

  • Description: Permitted number of recursive calls for a stored procedure. 0, the default, no recursion is permitted. Increasing this value increases the thread stack requirements, so you may need to increase thread_stack as well. This limit doesn't apply to stored functions.
  • Commandline: --max-sp-recursion-depth[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0 to 255

max_statement_time

  • Description: Maximum time in seconds that a query can execute before being aborted. This includes all queries, not just SELECT statements, but excludes statements in stored procedures. If set to 0, no limit is applied. See Aborting statements that take longer than a certain time to execute for details and limitations. Useful when combined with SET STATEMENT for limiting the execution times of individual queries. Replicas are not affected by this variable, however, from MariaDB 10.10, there's slave_max_statement_time that sets the limit to abort queries on a replica.
  • Commandline: --max-statement-time[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0.000000
  • Range: 0 to 31536000

max_tmp_tables


max_user_connections

  • Description: Maximum simultaneous connections permitted for each user account. When set to 0, there is no per user limit. Setting it to -1 stops users without the SUPER privilege or, from MariaDB 10.5.2, the CONNECTION ADMIN privilege, from connecting to the server. The session variable is always read-only and only privileged users can modify user limits. The session variable defaults to the global max_user_connections variable, unless the user's specific MAX_USER_CONNECTIONS resource option is non-zero. When both global variable and the user resource option are set, the user's MAX_USER_CONNECTIONS is used. Note: This variable does not affect users with the SUPER privilege or, from MariaDB 10.5.2, the CONNECTION ADMIN privilege.
  • Commandline: --max-user-connections=#
  • Scope: Global, Session
  • Dynamic: Yes, (except when globally set to 0 or -1)
  • Data Type: numeric
  • Default Value: 0
  • Range: -1 to 4294967295

max_write_lock_count

  • Description: Read lock requests will be permitted for processing after this many write locks. Applies only to storage engines that use table level locks (thr_lock), so no effect with InnoDB or Archive.
  • Commandline: --max-write-lock-count=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 4294967295
  • Range: 0-4294967295

metadata_locks_cache_size

  • Description: Unused since 10.1.4
  • Commandline: --metadata-locks-cache-size=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 1024
  • Range: 1 to 1048576

metadata_locks_hash_instances

  • Description: Unused since 10.1.4
  • Commandline: --metadata-locks-hash-instances=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 8
  • Range: 1 to 1024

min_examined_row_limit

  • Description: Don't write queries to slow query log that examine fewer rows than the set value. If set to 0, the default, no row limit is used. From MariaDB 10.11.0, this is an alias for log_slow_min_examined_row_limit.
  • Commandline: --min-examined-row-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0-4294967295

mrr_buffer_size

  • Description: Size of buffer to use when using multi-range read with range access. See Multi Range Read optimization for more information.
  • Commandline: --mrr-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 262144
  • Range 8192 to 2147483648

multi_range_count


mysql56_temporal_format

  • Description: If set (the default), MariaDB uses the MySQL 5.6 low level formats for TIME, DATETIME and TIMESTAMP instead of the MariaDB 5.3 version. The version MySQL introduced in 5.6 requires more storage, but potentially allows negative dates and has some advantages in replication. There should be no reason to revert to the old MariaDB 5.3 microsecond format. See also MDEV-10723.
  • Commandline: --mysql56-temporal-format
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: ON

named_pipe

  • Description: On Windows systems, determines whether connections over named pipes are permitted.
  • Commandline: --named-pipe
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: OFF

net_buffer_length

  • Description: The starting size, in bytes, for the connection and thread buffers for each client thread. The size can grow to max_allowed_packet. This variable's session value is read-only. Can be set to the expected length of client statements if memory is a limitation.
  • Commandline: --net-buffer-length=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16384
  • Range: 1024 to 1048576

net_read_timeout

  • Description: Time in seconds the server will wait for a client connection to send more data before aborting the read. See also net_write_timeout and slave_net_timeout
  • Commandline: --net-read-timeout=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 30
  • Range: 1 upwards

net_retry_count

  • Description: Permit this many retries before aborting when attempting to read or write on a communication port. On FreeBSD systems should be set higher as threads are sent internal interrupts..
  • Commandline: --net-retry-count=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 10
  • Range: 1 to 4294967295

net_write_timeout

  • Description: Time in seconds to wait on writing a block to a connection before aborting the write. See also net_read_timeout and slave_net_timeout.
  • Commandline: --net-write-timeout=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 60
  • Range: 1 upwards

note_verbosity

  • Description: Verbosity level for note-warnings given to the user. Options are added in a comma-delimited string, except for all, which sets all options. See also Notes when an index cannot be used. Be aware that if the old sql_notes variable is 0, one will not get any notes. Setting note_verbosity to "" is the recommended way to disable notes.
    • basic All old notes.
    • unusable_keys Give warnings for unusable keys for SELECT, DELETE and UPDATE.
    • explain Give warnings for unusable keys for EXPLAIN.
    • all Enables all above options. This has to be given alone.
  • Commandline: note-verbosity=value1[,value2...]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value: basic,explain
  • Valid Values: basic,explain,unusable_keys or all.
  • Introduced: MariaDB 10.6.16

old

  • Description: Disabled by default, enabling it reverts index hints to those used before MySQL 5.1.17. Enabling may lead to replication errors. Deprecated and replaced by old_mode from MariaDB 10.9.
  • Commandline: --old
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Deprecated: MariaDB 10.9

old_alter_table


old_mode

  • Description: Used for getting MariaDB to emulate behavior from an old version of MySQL or MariaDB. See OLD Mode. Fully replaces the old variable from MariaDB 10.9. Non-default OLD_MODE options are by design deprecated and will eventually be removed.
  • Commandline: --old-mode
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: UTF8_IS_UTF8MB3 (>= MariaDB 10.6) (empty string) (<= MariaDB 10.5)
  • Valid Values: See OLD Mode for the full list.

old_passwords

  • Description: If set to 1 (0 is default), MariaDB reverts to using the mysql_old_password authentication plugin by default for newly created users and passwords, instead of the mysql_native_password authentication plugin.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

open_files_limit


optimizer_extra_pruning_depth

  • Description:If the optimizer needs to enumerate a join prefix of this size or larger, then it will try aggressively prune away the search space.
  • Commandline: --optimizer-extra-pruning-depthl[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 8
  • Range: 0 to 62
  • Introduced: MariaDB 10.10.1

optimizer_max_sel_args

  • Description: The maximum number of SEL_ARG objects created when optimizing a range. If more objects would be needed, the range will not be used by the optimizer.
  • Commandline: --optimizer-max-sel-args=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16000
  • Range: 0 to 4294967295
  • Introduced: MariaDB 10.6.16

optimizer_max_sel_arg_weight

  • Description: The maximum weight of the SEL_ARG graph. Set to 0 for no limit.
  • Commandline: --optimizer-max-sel-arg-weight=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 32000
  • Range: 0 to 18446744073709551615
  • Introduced: MariaDB 10.5.9

optimizer_prune_level

  • Description:Controls the heuristic(s) applied during query optimization to prune less-promising partial plans from the optimizer search space.
    • 0: heuristics are disabled and an exhaustive search is performed
    • 1: the optimizer will use heuristics to prune less-promising partial plans from the optimizer search space
    • 2: tables using EQ_REF will be joined together as 'one entity' and the different combinations of these tables will not be considered (from MariaDB 10.10)
  • Commandline: --optimizer-prune-level[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 2 (>= MariaDB 10.10), 1 (<= MariaDB 10.9)

optimizer_search_depth

  • Description: Maximum search depth by the query optimizer. Smaller values lead to less time spent on execution plans, but potentially less optimal results. If set to 0, MariaDB will automatically choose a reasonable value. Since the better results from more optimal planning usually offset the longer time spent on planning, this is set as high as possible by default. 63 is a valid value, but its effects (switching to the original find_best search) are deprecated.
  • Commandline: --optimizer-search-depth[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 62
  • Range: 0 to 63

optimizer_selectivity_sampling_limit

  • Description: Controls number of record samples to check condition selectivity. Only used if optimizer_use_condition_selectivity > 4.
  • Commandline: optimizer-selectivity-sampling-limit[=#]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 100
  • Range: 10 upwards

optimizer_switch


optimizer_trace

  • Description: Controls tracing of the optimizer: optimizer_trace=option=val[,option=val...], where option is one of {enabled} and val is one of {on, off, default}
  • Commandline: --optimizer-trace=value
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enum
  • Default Value: enabled=off
  • Valid Values: enabled={on|off|default}
  • Introduced: MariaDB 10.4.3

optimizer_trace_max_mem_size

  • Description: Limits the memory used while tracing a query by specifying the maximum allowed cumulated size, in bytes, of stored optimizer traces.
  • Commandline: --optimizer-trace-max-mem-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1048576
  • Range: 1 to 18446744073709551615
  • Introduced: MariaDB 10.4.3

optimizer_use_condition_selectivity

  • Description: Controls which statistics can be used by the optimizer when looking for the best query execution plan.
    • 1 Use selectivity of predicates as in MariaDB 5.5.
    • 2 Use selectivity of all range predicates supported by indexes.
    • 3 Use selectivity of all range predicates estimated without histogram.
    • 4 Use selectivity of all range predicates estimated with histogram.
    • 5 Additionally use selectivity of certain non-range predicates calculated on record sample.
  • Commandline: --optimizer-use-condition-selectivity=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4 (>= MariaDB 10.4.1), 1 (<= MariaDB 10.4.0)
  • Range: 1 to 5

pid_file

  • Description: Full path of the process ID file.
  • Commandline: --pid-file=file_name
  • Scope: Global
  • Dynamic: No
  • Data Type: file name

plugin_dir

  • Description: Path to the plugin directory. For security reasons, either make sure this directory can only be read by the server, or set secure_file_priv.
  • Commandline: --plugin-dir=path
  • Scope: Global
  • Dynamic: No
  • Data Type: directory name
  • Default Value: BASEDIR/lib/plugin

plugin_maturity

  • Description: The lowest acceptable plugin maturity. MariaDB will not load plugins less mature than the specified level.
  • Commandline: --plugin-maturity=level
  • Scope: Global
  • Dynamic: No
  • Type: enum
  • Default Value: One less than the server maturity (>= MariaDB 10.3.3), unknown (<= MariaDB 10.3.2)
  • Valid Values: unknown, experimental, alpha, beta, gamma, stable

port

  • Description: Port to listen for TCP/IP connections. If set to 0, will default to, in order of preference, my.cnf, the MYSQL_TCP_PORT environment variable, /etc/services, built-in default (3306).
  • Commandline: --port=#, -P
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 3306
  • Range: 0 to 65535

preload_buffer_size

  • Description: Size in bytes of the buffer allocated when indexes are preloaded.
  • Commandline: --preload-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 32768
  • Range: 1024 to 1073741824

profiling

  • Description: If set to 1 (0 is default), statement profiling will be enabled. See SHOW PROFILES() and SHOW PROFILE().
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

profiling_history_size

  • Description: Number of statements about which profiling information is maintained. If set to 0, no profiles are stored. See SHOW PROFILES.
  • Commandline: --profiling-history-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 15
  • Range: 0 to 100

progress_report_time

  • Description: Time in seconds between sending progress reports to the client for time-consuming statements. If set to 0, progress reporting will be disabled.
  • Commandline: --progress-report-time=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 5
  • Range: 0 to 4294967295

protocol_version

  • Description: The version of the client/server protocol used by the MariaDB server.
  • Commandline: None
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 10
  • Range: 0 to 4294967295

proxy_protocol_networks

  • Description: Enable proxy protocol for these source networks. The syntax is a comma separated list of IPv4 and IPv6 networks. If the network doesn't contain a mask, it is considered to be a single host. "*" represents all networks and must be the only directive on the line. String "localhost" represents non-TCP local connections (Unix domain socket, Windows named pipe or shared memory). See Proxy Protocol Support.
  • Commandline: --proxy-protocol-networks=value
  • Scope: Global
  • Dynamic: Yes (>= MariaDB 10.3.6), No (<= MariaDB 10.3.5)
  • Data Type: string
  • Default Value: (empty)
  • Introduced: MariaDB 10.3.1

proxy_user

  • Description: Set to the proxy user account name if the current client is a proxy, else NULL.
  • Scope: Session
  • Dynamic: No
  • Data Type: string

pseudo_slave_mode

  • Description: For internal use by the server.
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: OFF

pseudo_thread_id

  • Description: For internal use only.
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric

query_alloc_block_size

  • Description: Size in bytes of the extra blocks allocated during query parsing and execution (after query_prealloc_size is used up).
  • Commandline: --query-alloc-block-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16384
  • Range - 32 bit: 1024 to 4294967295
  • Range - 64 bit: 1024 to 18446744073709547520

query_cache_limit

  • Description: Size in bytes for which results larger than this are not stored in the query cache.
  • Commandline: --query-cache-limit=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1048576 (1MB)
  • Range: 0 to 4294967295

query_cache_min_res_unit

  • Description: Minimum size in bytes of the blocks allocated for query cache results.
  • Commandline: --query-cache-min-res-unit=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4096 (4KB)
  • Range - 32 bit: 1024 to 4294967295
  • Range - 64 bit: 1024 to 18446744073709547520

query_cache_size

  • Description: Size in bytes available to the query cache. About 40KB is needed for query cache structures, so setting a size lower than this will result in a warning. 0, the default before MariaDB 10.1.7, effectively disables the query cache.

Warning: Starting from MariaDB 10.1.7, query_cache_type is automatically set to ON if the server is started with the query_cache_size set to a non-zero (and non-default) value. This will happen even if query_cache_type is explicitly set to OFF in the configuration.

  • Commandline: --query-cache-size=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 1M (although frequently given a default value in some setups)
  • Valid Values: 0 upwards in units of 1024.

query_cache_strip_comments

  • Description: If set to 1 (0 is default), the server will strip any comments from the query before searching to see if it exists in the query cache. Multiple space, line feeds, tab and other white space characters will also be removed.
  • Commandline: query-cache-strip-comments
  • Scope: Session, Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

query_cache_type

  • Description: If set to 0, the query cache is disabled (although a buffer of query_cache_size bytes is still allocated). If set to 1 all SELECT queries will be cached unless SQL_NO_CACHE is specified. If set to 2 (or DEMAND), only queries with the SQL CACHE clause will be cached. Note that if the server is started with the query cache disabled, it cannot be enabled at runtime.

Warning: Starting from MariaDB 10.1.7, query_cache_type is automatically set to ON if the server is started with the query_cache_size set to a non-zero (and non-default) value. This will happen even if query_cache_type is explicitly set to OFF in the configuration.

  • Commandline: --query-cache-type=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enumeration
  • Default Value: OFF
  • Valid Values: 0 or OFF, 1 or ON, 2 or DEMAND

query_cache_wlock_invalidate

  • Description: If set to 0, the default, results present in the query cache will be returned even if there's a write lock on the table. If set to 1, the client will first have to wait for the lock to be released.
  • Commandline: --query-cache-wlock-invalidate
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

query_prealloc_size

  • Description: Size in bytes of the persistent buffer for query parsing and execution, allocated on connect and freed on disconnect. Increasing may be useful if complex queries are being run, as this will reduce the need for more memory allocations during query operation. See also query_alloc_block_size.
  • Commandline: --query-prealloc-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 24576
  • Range: 1024 to 4294967295

rand_seed1

  • Description: rand_seed1 and rand_seed2 facilitate replication of the RAND() function. The master passes the value of these to the slaves so that the random number generator is seeded in the same way, and generates the same value, on the slave as on the master. Until MariaDB 10.1.4, the variable value could not be viewed, with the SHOW VARIABLES output always displaying zero.
  • Commandline: None
  • Scope: Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: Varies
  • Range: 0 to 18446744073709551615

rand_seed2


range_alloc_block_size

  • Description: Size in bytes of blocks allocated during range optimization. The unit size in 1024.
  • Commandline: --range-alloc-block-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 4096
  • Range - 32 bit: 4096 to 4294967295
  • Range - 64 bit: 4096 to 18446744073709547520

read_buffer_size

  • Description: Each thread performing a sequential scan (for MyISAM, Aria and MERGE tables) allocates a buffer of this size in bytes for each table scanned. Increase if you perform many sequential scans. If not in a multiple of 4KB, will be rounded down to the nearest multiple. Also used in ORDER BY's for caching indexes in a temporary file (not temporary table), for caching results of nested queries, for bulk inserts into partitions, and to determine the memory block size of MEMORY tables.
  • Commandline: --read-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 131072
  • Range: 8200 to 2147479552

read_only

  • Description: When set to 1 (0 is default), no updates are permitted except from users with the SUPER privilege or, from MariaDB 10.5.2, the READ ONLY ADMIN privilege, or replica servers updating from a primary. The read_only variable is useful for replica servers to ensure no updates are accidentally made outside of what are performed on the primary. Inserting rows to log tables, updates to temporary tables and OPTIMIZE TABLE or ANALYZE TABLE statements are excluded from this limitation. If read_only is set to 1, then the SET PASSWORD statement is limited only to users with the SUPER privilege (<= MariaDB 10.5.1) or READ ONLY ADMIN privilege (>= MariaDB 10.5.2). Attempting to set this variable to 1 will fail if the current session has table locks or transactions pending, while if other sessions hold table locks, the statement will wait until these locks are released before completing. While the attempt to set read_only is waiting, other requests for table locks or transactions will also wait until read_only has been set. See Read-Only Replicas for more. From MariaDB 10.5.2, the READ_ONLY ADMIN privilege will allow users granted that privilege to perform writes, even if the read_only variable is set. In earlier versions, and until MariaDB 10.11.0, users with the SUPER can perform writes while this variable is set.
  • Commandline: --read-only
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

read_rnd_buffer_size

  • Description: Size in bytes of the buffer used when reading rows from a MyISAM table in sorted order after a key sort. Larger values improve ORDER BY performance, although rather increase the size by SESSION where the need arises to avoid excessive memory use.
  • Commandline: --read-rnd-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 262144
  • Range: 8200 to 2147483647

redirect_url

  • Description: URL of another server to redirect clients to. Empty string means no redirection.
  • Commandline: --redirect_url=val
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: Empty
  • Introduced: MariaDB 11.3.0

-

-

require_secure_transport

  • Description: When this option is enabled, connections attempted using insecure transport will be rejected. Secure transports are SSL/TLS, Unix sockets or named pipes. Note that per-account requirements take precedence.
  • Commandline: --require-secure-transport[={0|1}]
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Introduced: MariaDB 10.5.2

rowid_merge_buff_size

  • Description: The maximum size in bytes of the memory available to the Rowid-merge strategy. See Non-semi-join subquery optimizations for more information.
  • Commandline: --rowid-merge-buff-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 8388608
  • Range: 0 to 2147483647

rpl_recovery_rank


safe_show_database

  • Description: This variable was removed in MariaDB 5.5, and has been replaced by the more flexible SHOW DATABASES privilege.
  • Commandline: --safe-show-database (until MySQL 4.1.1)
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Removed: MariaDB 5.5

secure_auth


secure_file_priv

  • Description: LOAD DATA, SELECT ... INTO and LOAD FILE() will only work with files in the specified path. If not set, the default, or set to empty string, the statements will work with any files that can be accessed.
  • Commandline: --secure-file-priv=path
  • Scope: Global
  • Dynamic: No
  • Data Type: path name
  • Default Value: None

secure_timestamp

  • Description: Restricts direct setting of a session timestamp. Possible levels are:
    • YES - timestamp cannot deviate from the system clock. Intended to prevent tampering with system versioning history. Should not be used on replicas, as when a value based on the timestamp is inserted in statement mode, discrepancies can occur.
    • REPLICATION - replication thread can adjust timestamp to match the primary's
    • SUPER - a user with this privilege and a replication thread can adjust timestamp
    • NO - historical behavior, anyone can modify session timestamp
  • Commandline: --secure-timestamp=value
  • Scope: Global
  • Dynamic: No
  • Data Type: enum
  • Default Value: NO

session_track_schema

  • Description: Whether to track changes to the default schema within the current session.
  • Commandline: --session-track-schema={0|1}
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: ON

session_track_state_change

  • Description: Whether to track changes to the session state.
  • Commandline: --session-track-state-change={0|1}
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

session_track_system_variables

  • Description: Comma-separated list of session system variables for which to track changes. For compatibility with MySQL defaults, this variable should be set to "autocommit, character_set_client, character_set_connection, character_set_results, time_zone". The * character tracks all session variables.
  • Commandline: --session-track-system-variables=value
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value:
    • >= MariaDB 11.3: autocommit,character_set_client,character_set_connection,character_set_results,redirect_url,time_zone
    • <= MariaDB 11.2: autocommit, character_set_client, character_set_connection, character_set_results, time_zone

session_track_transaction_info

  • Description: Track changes to the transaction attributes. OFF to disable; STATE to track just transaction state (Is there an active transaction? Does it have any data? etc.); CHARACTERISTICS to track transaction state and report all statements needed to start a transaction with the same characteristics (isolation level, read only/read write,snapshot - but not any work done / data modified within the transaction).
  • Commandline: --session-track-transaction-info=value
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enum
  • Default Value: OFF
  • Valid Values: OFF, STATE, CHARACTERISTICS

shared_memory

  • Description: Windows only, determines whether the server permits shared memory connections. See also shared_memory_base_name.
  • Scope: Global
  • Dynamic: No

shared_memory_base_name

  • Description: Windows only, specifies the name of the shared memory to use for shared memory connection. Mainly used when running more than one instance on the same physical machine. By default the name is MYSQL and is case sensitive. See also shared_memory.
  • Scope: Global
  • Dynamic: No
  • Data Type: string
  • Default Value: MYSQL

skip_external_locking

  • Description: If this system variable is set, then some kinds of external table locks will be disabled for some storage engines.
    • If this system variable is set, then the MyISAM storage engine will not use file-based locks. Otherwise, it will use the fcntl() function with the F_SETLK option to get file-based locks on Unix, and it will use the LockFileEx() function to get file-based locks on Windows.
    • If this system variable is set, then the Aria storage engine will not lock a table when it decrements the table's in-file counter that keeps track of how many connections currently have the table open. See MDEV-19393 for more information.
  • Commandline: --skip-external-locking
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: 1

skip_grant_tables


skip_name_resolve

  • Description: If set to 1 (0 is the default), only IP addresses are used for connections. Host names are not resolved. All host values in the GRANT tables must be IP addresses (or localhost).
  • Commandline: --skip-name-resolve
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: 0

skip_networking

  • Description: If set to 1, (0 is the default), the server does not listen for TCP/IP connections. All interaction with the server will be through socket files (Unix) or named pipes or shared memory (Windows). It's recommended to use this option if only local clients are permitted to connect to the server.
  • Commandline: --skip-networking
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: 0

skip_show_database

  • Description: If set to 1, (0 is the default), only users with the SHOW DATABASES privilege can use the SHOW DATABASES statement to see all database names.
  • Commandline: --skip-show-database
  • Scope: Global
  • Dynamic: No
  • Data Type: boolean
  • Default Value: 0

slow_launch_time

  • Description: Time in seconds. If a thread takes longer than this to launch, the slow_launch_threads server status variable is incremented.
  • Commandline: --slow-launch-time=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 2

slow_query_log

  • Description: If set to 0, the default unless the --slow-query-log option is used, the slow query log is disabled, while if set to 1 (both global and session variables), the slow query log is enabled. From MariaDB 10.11.0, an alias for log_slow_query.
  • Commandline: --slow-query-log
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Data Type: boolean
  • Default Value: 0
  • See also: See log_output to see how log files are written. If that variable is set to NONE, no logs will be written even if slow_query_log is set to 1.

slow_query_log_file


socket

  • Description: On Unix-like systems, this is the name of the socket file used for local client connections, by default /tmp/mysql.sock, often changed by the distribution, for example /var/lib/mysql/mysql.sock. On Windows, this is the name of the named pipe used for local client connections, by default MySQL. On Windows, this is not case-sensitive.
  • Commandline: --socket=name
  • Scope: Global
  • Dynamic: No
  • Data Type: file name
  • Default Value: /tmp/mysql.sock (Unix), MySQL (Windows)

sort_buffer_size

  • Description: Each session performing a sort allocates a buffer with this amount of memory. Not specific to any storage engine. If the status variable sort_merge_passes is too high, you may need to look at improving your query indexes, or increasing this. Consider reducing where there are many small sorts, such as OLTP, and increasing where needed by session. 16k is a suggested minimum.
  • Commandline: --sort-buffer-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: number
  • Default Value: 2M (2097152) (some distributions increase the default)

sql_auto_is_null

  • Description: If set to 1, the query SELECT * FROM table_name WHERE auto_increment_column IS NULL will return an auto-increment that has just been successfully inserted, the same as the LAST_INSERT_ID() function. Some ODBC programs make use of this IS NULL comparison.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0

sql_big_selects

  • Description: If set to 0, MariaDB will not perform large SELECTs. See max_join_size for details. If max_join_size is set to anything but DEFAULT, sql_big_selects is automatically set to 0. If sql_big_selects is again set, max_join_size will be ignored.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

sql_big_tables

  • Description: Old variable, which if set to 1, allows large result sets by saving all temporary sets to disk, avoiding 'table full' errors. No longer needed, as the server now handles this automatically.
  • Commandline: --sql-big-tables
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0
  • Removed: MariaDB 10.0

sql_buffer_result

  • Description: If set to 1 (0 is default), results from SELECT statements are always placed into temporary tables. This can help the server when it takes a long time to send the results to the client by allowing the table locks to be freed early.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0

sql_if_exists

  • Description: If set to 1, adds an implicit IF EXISTS to ALTER, RENAME and DROP of TABLES, VIEWS, FUNCTIONS and PACKAGES. This variable is mainly used in replication to tag DDLs that can be ignored on the slave if the target table doesn't exist.
  • Commandline: --sql-if-exists[={0|1}]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Introduced: MariaDB 10.5.2

sql_log_off

  • Description: If set to 1 (0 is the default), no logging to the general query log is done for the client. Only clients with the SUPER privilege can update this variable.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0

sql_log_update

  • Description: Removed. Use sql_log_bin instead.
  • Removed: MariaDB/MySQL 5.5

sql_low_priority_updates

  • Description: If set to 1 (0 is the default), for storage engines that use only table-level locking (Aria, MyISAM, MEMORY and MERGE), all INSERTs, UPDATEs, DELETEs and LOCK TABLE WRITEs will wait until there are no more SELECTs or LOCK TABLE READs pending on the relevant tables. Set this to 1 if reads are prioritized over writes.
  • Commandline: --sql-low-priority-updates
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 0
  • Removed: MariaDB 10.0

sql_max_join_size


sql_mode

  • Description: Sets the SQL Mode. Multiple modes can be set, separated by a comma.
  • Commandline: --sql-mode=value[,value[,value...]]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value:
    • STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
  • Valid Values: See SQL Mode for the full list.

sql_notes

  • Description: If set to 1, the default, warning_count is incremented each time a Note warning is encountered. If set to 0, Note warnings are not recorded. mariadb-dump has outputs to set this variable to 0 so that no unnecessary increments occur when data is reloaded. See also note_verbosity, which defines which notes should be given. The recommended way, as of MariaDB 10.6.16, to disable notes is to set note_verbosity to "".
  • Commandline: None
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

sql_quote_show_create

  • Description: If set to 1, the default, the server will quote identifiers for SHOW CREATE DATABASE, SHOW CREATE TABLE and SHOW CREATE VIEW statements. Quoting is disabled if set to 0. Enable to ensure replication works when identifiers require quoting.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1

sql_safe_updates

  • Description: If set to 1, UPDATEs and DELETEs must be executed by using an index (simply mentioning an indexed column in a WHERE clause is not enough, optimizer must actually use it) or they must mention an indexed column and specify a LIMIT clause. Otherwise a statement will be aborted. Prevents the common mistake of accidentally deleting or updating every row in a table. Until MariaDB 10.3.11, could not be set as a command-line option or in my.cnf.
  • Commandline: --sql-safe-updates[={0|1}]
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF

sql_select_limit

  • Description: Maximum number of rows that can be returned from a SELECT query. Default is the maximum number of rows permitted per table by the server, usually 232-1 or 264-1. Can be restored to the default value after being changed by assigning it a value of DEFAULT.
  • Commandline: None
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 18446744073709551615

sql_warnings

  • Description: If set to 1, single-row INSERTs will produce a string containing warning information if a warning occurs.
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF (0)

storage_engine


standard_compliant_cte

  • Description: Allow only standard-compliant common table expressions. Prior to MariaDB 10.2.4, this variable was named standards_compliant_cte.
  • Commandline: --standard-compliant-cte={0|1}
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: ON
  • Introduced: MariaDB 10.2.2

stored_program_cache

  • Description: Limit to the number of stored routines held in the stored procedures and stored functions caches. Each time a stored routine is executed, this limit is first checked, and if the number held in the cache exceeds this, that cache is flushed and memory freed.
  • Commandline: --stored-program-cache=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 256
  • Range: 256 to 524288

strict_password_validation

  • Description: When password validation plugins are enabled, reject passwords that cannot be validated (passwords specified as a hash). This excludes direct updates to the privilege tables.
  • Commandline: --strict-password-validation
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: ON

sync_frm

  • Description: If set to 1, the default, each time a non-temporary table is created, its .frm definition file is synced to disk. Fractionally slower, but safer in case of a crash.
  • Commandline: --sync-frm
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: TRUE

system_time_zone

  • Description: The system time zone is determined when the server starts. The system time zone is usually read from the operating system's environment but can be overridden by setting the 'TZ' environment variable before starting the server. See Time Zones: System Time Zone for the various ways to change the system time zone. This variable is not the same as the time_zone system variable, which is the variable that actually controls a session's active time zone. The system time zone is used for a session when time_zone is set to the special value SYSTEM.
  • Scope: Global
  • Dynamic: No
  • Data Type: string

table_definition_cache


table_lock_wait_timeout

  • Description: Unused, and removed.
  • Commandline: --table-lock-wait-timeout=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 50
  • Range: 1 to 1073741824
  • Removed: MariaDB 5.5

table_open_cache

  • Description: Maximum number of open tables cached in one table cache instance. See Optimizing table_open_cache for suggestions on optimizing. Increasing table_open_cache increases the number of file descriptors required.
  • Commandline: --table-open-cache=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 2000
  • Range:
    • 1 to 1048576 (1024K)

table_open_cache_instances

  • Description: This system variable specifies the maximum number of table cache instances. MariaDB Server initially creates just a single instance. However, whenever it detects contention on the existing instances, it will automatically create a new instance. When the number of instances has been increased due to contention, it does not decrease again. The default value of this system variable is 8, which is expected to handle up to 100 CPU cores. If your system is larger than this, then you may benefit from increasing the value of this system variable.
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 8 (>= MariaDB 10.2.2)
  • Range: 1 to 64
  • Introduced: MariaDB 10.2.2

table_type


tcp_keepalive_interval

  • Description: The interval, in seconds, between when successive keep-alive packets are sent if no acknowledgement is received. If set to 0, the system dependent default is used.
  • Commandline: --tcp-keepalive-interval=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0 to 2147483
  • Introduced: MariaDB 10.3.3

tcp_keepalive_probes

  • Description: The number of unacknowledged probes to send before considering the connection dead and notifying the application layer. If set to 0, a system dependent default is used.
  • Commandline: --tcp-keepalive-probes=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0 to 2147483
  • Introduced: MariaDB 10.3.3

tcp_keepalive_time

  • Description: Timeout, in seconds, with no activity until the first TCP keep-alive packet is sent. If set to 0, a system dependent default is used.
  • Commandline: --tcp-keepalive-time=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 0
  • Range: 0 to 2147483
  • Introduced: MariaDB 10.3.3

tcp_nodelay

  • Description: Set the TCP_NODELAY option (disable Nagle's algorithm) on socket.
  • Commandline: --tcp-nodelay={0|1}
  • Scope: Session
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: 1
  • Introduced: MariaDB 10.4.0

thread_cache_size

  • Description: Number of threads server caches for re-use. If this limit hasn't been reached, when a client disconnects, its threads are put into the cache, and re-used where possible. In MariaDB 10.2.0 and newer the threads are freed after 5 minutes of idle time. Normally this setting has little effect, as the other aspects of the thread implementation are more important, but increasing it can help servers with high volumes of connections per second so that most can use a cached, rather than a new, thread. The cache miss rate can be calculated as the server status variables threads_created/connections. If the thread pool is active, thread_cache_size is ignored. If thread_cache_size is set to greater than the value of max_connections, thread_cache_size will be set to the max_connections value.
  • Commandline: --thread-cache-size=#
  • Scope: Global
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 256 (adjusted if thread pool is active)
  • Range: 0 to 16384

thread_concurrency

  • Description: Allows applications to give the system a hint about the desired number of threads. Specific to Solaris only, invokes thr_setconcurrency(). Deprecated and has no effect from MariaDB 5.5.
  • Commandline: --thread-concurrency=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value: 10
  • Range: 1 to 512
  • Deprecated: MariaDB 5.5
  • Removed: MariaDB 10.5.1

thread_stack

  • Description: Stack size for each thread. If set too small, limits recursion depth of stored procedures and complexity of SQL statements the server can handle in memory. Also affects limits in the crash-me test.
  • Commandline: --thread-stack=#
  • Scope: Global
  • Dynamic: No
  • Data Type: numeric
  • Default Value:
    • 299008
  • Range: 131072 to 18446744073709551615

time_format


time_zone

  • Description: The global value determines the default time zone for sessions that connect. The session value determines the session's active time zone. When it is set to SYSTEM, the session's time zone is determined by the system_time_zone system variable.
  • Commandline: --default-time-zone=string
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: string
  • Default Value: SYSTEM

timed_mutexes

  • Description: Determines whether InnoDB mutexes are timed. OFF, the default, disables mutex timing, while ON enables it. See also SHOW ENGINE for more on mutex statistics. Deprecated and has no effect.
  • Commandline: --timed-mutexes
  • Scope: Global
  • Dynamic: Yes
  • Data Type: boolean
  • Default Value: OFF
  • Deprecated: MariaDB 5.5.39
  • Removed: MariaDB 10.5.1

timestamp

  • Description: Sets the time for the client. This will affect the result returned by the NOW() function, not the SYSDATE() function, unless the server is started with the --sysdate-is-now option, in which case SYSDATE becomes an alias of NOW, and will also be affected. Also used to get the original timestamp when restoring rows from the binary log.
  • Scope: Session
  • Dynamic: Yes
  • Valid Values: timestamp_value (Unix epoch timestamp, not MariaDB timestamp), DEFAULT

tmp_disk_table_size

  • Description: Max size for data for an internal temporary on-disk MyISAM or Aria table. These tables are created as part of complex queries when the result doesn't fit into the memory engine. You can set this variable if you want to limit the size of temporary tables created in your temporary directory tmpdir.
  • Commandline: --tmp-disk-table-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 18446744073709551615 (max unsigned integer, no limit)
  • Range: 1024 to 18446744073709551615
  • Introduced: MariaDB 10.2.7

tmp_memory_table_size


tmp_table_size

  • Description: The largest size for temporary tables in memory (not MEMORY tables) although if max_heap_table_size is smaller the lower limit will apply. You can see if it's necessary to increase by comparing the status variables Created_tmp_disk_tables and Created_tmp_tables to see how many temporary tables out of the total created needed to be converted to disk. Often complex GROUP BY queries are responsible for exceeding the limit. Defaults may be different on some systems, see for example Differences in MariaDB in Debian. From MariaDB 10.2.7, tmp_memory_table_size is an alias.
  • Commandline: --tmp-table-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: numeric
  • Default Value: 16777216 (16MB)
  • Range:

tmpdir

  • Description: Directory for storing temporary tables and files. Can specify a list (separated by semicolons in Windows, and colons in Unix) that will then be used in round-robin fashion. This can be used for load balancing across several disks. Note that if the server is a replication replica, and slave_load_tmpdir, which overrides tmpdir for replicas, is not set, you should not set tmpdir to a directory that is cleared when the machine restarts, or else replication may fail.
  • Commandline: --tmpdir=path or -t path
  • Scope: Global
  • Dynamic: No
  • Type: directory name/s
  • Default:
    • $TMPDIR (environment variable) if set
    • otherwise $TEMP if set and on Windows
    • otherwise $TMP if set and on Windows
    • otherwise P_tmpdir ("/tmp") or C:\TEMP (unless overridden during buid time)

transaction_alloc_block_size

  • Description: Size in bytes to increase the memory pool available to each transaction when the available pool is not large enough. See transaction_prealloc_size.
  • Commandline: --transaction-alloc-block-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 8192
  • Range: 1024 to 4294967295
  • Block Size: 1024

transaction_isolation

  • Description: The transaction isolation level. See also SET TRANSACTION ISOLATION LEVEL. Introduced in MariaDB 11.1.1 to replace the tx_isolation system variable and align the option and the system variable name.
  • Commandline: --transaction-isolation=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: enumeration
  • Default Value: REPEATABLE-READ
  • Valid Values: READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, SERIALIZABLE
  • Introduced: MariaDB 11.1.1

transaction_prealloc_size

  • Description: Initial size of a memory pool available to each transaction for various memory allocations. If the memory pool is not large enough for an allocation, it is increased by transaction_alloc_block_size bytes, and truncated back to transaction_prealloc_size bytes when the transaction is completed. If set large enough to contain all statements in a transaction, extra malloc() calls are avoided.
  • Commandline: --transaction-prealloc-size=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 4096
  • Range: 1024 to 4294967295
  • Block Size: 1024

transaction_read_only

  • Description: Default transaction access mode. If set to OFF, the default, access is read/write. If set to ON, access is read-only. The SET TRANSACTION statement can also change the value of this variable. See SET TRANSACTION and START TRANSACTION.
  • Commandline: --transaction-read-only=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: boolean
  • Default Value: OFF
  • Introduced: MariaDB 11.1

tx_isolation

  • Description: The transaction isolation level. Setting this session variable via set @@tx_isolation= will take effect for only the subsequent transaction in the current session, much like SET TRANSACTION ISOLATION LEVEL. To set for a session, use SET SESSION tx_isolation or SET @@session.tx_isolation. See MDEV-31751. See also SET TRANSACTION ISOLATION LEVEL. In MariaDB 11.1, this system variable is deprecated and replaced by transaction_isolation.
  • Commandline: --transaction-isolation=name
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: enumeration
  • Default Value: REPEATABLE-READ
  • Valid Values: READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, SERIALIZABLE
  • Deprecated: MariaDB 11.1

tx_read_only

  • Description: Default transaction access mode. If set to OFF, the default, access is read/write. If set to ON, access is read-only. The SET TRANSACTION statement can also change the value of this variable. See SET TRANSACTION and START TRANSACTION. In MariaDB 11.1, this system variable is deprecated and replaced by transaction_read_only.
  • Commandline: --transaction-read-only=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: boolean
  • Default Value: OFF
  • Deprecated: MariaDB 11.1

unique_checks

  • Description: If set to 0, storage engines can (but are not required to) assume that duplicate keys are not present in input data. If set to 0, inserting duplicates into a UNIQUE index can succeed, causing the table to become corrupted. Set to 0 to speed up imports of large tables to InnoDB.
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: boolean
  • Default Value: 1

updatable_views_with_limit

  • Description: Determines whether view updates can be made with an UPDATE or DELETE statement with a LIMIT clause if the view does not contain all primary or not null unique key columns from the underlying table. 0 prohibits this, while 1 permits it while issuing a warning (the default).
  • Commandline: --updatable-views-with-limit=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: boolean
  • Default Value: 1

use_stat_tables

  • Description: Controls the use of engine-independent table statistics.
    • never: The optimizer will not use data from statistics tables.
    • complementary: The optimizer uses data from statistics tables if the same kind of data is not provided by the storage engine.
    • preferably: Prefer the data from statistics tables, if it's not available there, use the data from the storage engine.
    • complementary_for_queries: Same as complementary, but for queries only (to avoid needlessly collecting for ANALYZE TABLE). From MariaDB 10.4.1.
    • preferably_for_queries: Same as preferably, but for queries only (to avoid needlessly collecting for ANALYZE TABLE). From MariaDB 10.4.1.
  • Commandline: --use-stat-tables=mode
  • Scope: Global, Session
  • Dynamic: Yes
  • Data Type: enum
  • Default Value: preferably_for_queries (>= MariaDB 10.4.1), never (<= MariaDB 10.4.0)

version

  • Description: Server version number. It may also include a suffix with configuration or build information. -debug indicates debugging support was enabled on the server, and -log indicates at least one of the binary log, general log or slow query log are enabled, for example 10.0.1-MariaDB-mariadb1precise-log. Can be set at startup in order to fake the server version.
  • Commandline: -V, --version[=name]
  • Scope: Global
  • Dynamic: No
  • Type: string

version_comment

  • Description: Value of the COMPILATION_COMMENT option specified by CMake when building MariaDB, for example mariadb.org binary distribution.
  • Scope: Global
  • Dynamic: No
  • Type: string

version_compile_machine

  • Description: The machine type or architecture MariaDB was built on, for example i686.
  • Scope: Global
  • Dynamic: No
  • Type: string

version_compile_os

  • Description: Operating system that MariaDB was built on, for example debian-linux-gnu.
  • Scope: Global
  • Dynamic: No
  • Type: string

version_malloc_library

  • Description: Version of the used malloc library.
  • Commandline: No
  • Scope: Global
  • Dynamic: No
  • Type: string

version_source_revision

  • Description: Source control revision id for MariaDB source code, enabling one to see exactly which version of the source was used for a build.
  • Commandline: None
  • Scope: Global
  • Dynamic: No
  • Type: string
  • Introduced: MariaDB 10.3.2

wait_timeout

  • Description: Time in seconds that the server waits for a connection to become active before closing it. The session value is initialized when a thread starts up from either the global value, if the connection is non-interactive, or from the interactive_timeout value, if the connection is interactive.
  • Commandline: --wait-timeout=#
  • Scope: Global, Session
  • Dynamic: Yes
  • Type: numeric
  • Default Value: 28800
  • Range: (Windows): 1 to 2147483
  • Range: (Other): 1 to 31536000

warning_count

  • Description: Read-only variable indicating the number of warnings, errors and notes resulting from the most recent statement that generated messages. See SHOW WARNINGS for more. Note warnings will only be recorded if sql_notes is true (the default).
  • Scope: Session
  • Dynamic: No
  • Type: numeric

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