System Variable Differences Between MariaDB 10.3 and MySQL 8.0
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The following is a comparison of variables that either appear only in MariaDB 10.3 or MySQL 8.0, or have different default settings in MariaDB 10.3, and MySQL 8.0. MariaDB 10.3.10 and MySQL 8.0.11, with only default plugins enabled, were used for the comparison. Note that MySQL 8 is an 'evergreen' release, so features may be added or removed in later releases.
The most notable differences are that MariaDB includes, by default, the Aria storage engine (resulting in extra memory allocation), Galera Cluster, and has a different thread pool implementation. For this reason, a default implementation of MariaDB 10.3 will use more memory than MySQL 8.0. MariaDB 10.3 and MySQL 8.0 also have different GTID implementations.
MariaDB's extra memory usage can be handled with the following rules of thumb:
- If you are not using MyISAM and don't plan to use Aria:
- Set key_buffer_size to something very low (16K) as it's not used.
- Set aria_pagecache_buffer_size to what you think you need for handling internal tmp tables that didn't fit in memory.
- Normally this is what before you had set for key_buffer_size (at least 1M).
- If you are using MyISAM and not planning to use Aria:
- Set aria_pagecache_buffer_size to what you think you need for handling internal tmp tables that didn't fit in memory.
- If you are planning to use Aria, you should set aria_pagecache_buffer_size to something that fits a big part of your normal data + overflow temporary tables.
Comparison Table
| Variable | MariaDB 10.3 Default | MySQL 8.0 Default | Notes |
|---|---|---|---|
| activate_all_roles_on_login | - | OFF | Determines whether to automatically activate roles on login. |
| alter_algorithm | DEFAULT | - | MariaDB 10.3 introduces new ALTER TABLE ALGORITHM clauses to avoid slow copies in certain instances. This variable allows setting this if no ALGORITHM clause is specified. |
| aria_* | * | - | The Aria storage engine is only available in MariaDB. |
| auto_generate_certs | - | ON | Whether to automatically generate SSL key and certificate files. |
| avoid_temporal_upgrade | - | OFF | Determines whether ALTER TABLE implicitly upgrades temporal columns. |
| back_log | Autosized | Autosized | MariaDB and MySQL have different autosizing algorithms. |
| binlog-annotate-row-events | ON | - | Introduced in MariaDB 5.3 for replicating between MariaDB 5.3 and MySQL/MariaDB 5.1. |
| binlog_commit_wait_count | 0 | - | For use in MariaDB's parallel replication. |
| binlog_commit_wait_usec | 100000 | - | For use in MariaDB's parallel replication. |
| binlog_error_action | ABORT_SERVER | MySQL-only variable for controlling what happens when the server cannot write to the binary log. | |
| binlog_expire_logs_seconds | - | 2592000 | Sets the binary log expiration period in seconds |
| binlog_file_cache_size | 16184 | - | For setting the size of the file cache for the binary log. |
| binlog_format | MIXED | ROW | MariaDB and MySQL have differing binary log formats. |
| binlog_group_commit_sync_delay | 0 | MySQL-only variable for controlling the wait time before synchronizing the binary log file to disk. | |
| binlog_group_commit_sync_no_delay_count | 0 | MySQL-only variable for setting the maximum number of transactions to wait for before aborting the current binlog_group_commit_sync_delay delay. | |
| binlog_gtid_simple_recovery | - | ON | MySQL-only GTID variable. MariaDB's GTID implementation is different. |
| binlog_max_flush_queue_time | - | 0 | Specifies a timeout for reading transactions from the flush queue before continuing with group commit and syncing log to disk. |
| binlog_optimize_thread_scheduling | ON | - | For optimized kernel thread scheduling. |
| binlog_order_commits | - | ON | Determines whether transactions may be committed in parallel. |
| binlog_row_metadata | - | MINIMAL | Determines the amount of table metadata added to the binary log with row-based logging. |
| binlog_row_value_options | - | (empty) | Permits an alternative binlog format for JSON document updates. |
| binlog_rows_query_log_events | - | OFF | MySQL-only variable for logging extra information in row-based logging. |
| binlog_transaction_dependency_history_size | - | 25000 | Maximum number of row hashes kept for looking up transactions that last modified a given row. |
| binlog_transaction_dependency_tracking | - | COMMIT_ORDER | For determining how to best use the slave's multithreaded applier. |
| block_encryption_mode | - | aes-128-ecb | MySQL-only variable for controlling the block encryption mode for block-based algorithms. |
| caching_sha2_password* | - | * | For use with MySQL's SHA-256 authentication with caching. |
| character_set_* | latin1 or utf8 | utf8mb4 | MySQL 8.0 defaults to the utf8mb4 character set. |
| check_constraint_checks | ON | - | Permits disabling constraint checks, for example when loading a table that violates some constraints that you plan to fix later. |
| check_proxy_users | OFF | MySQL-only variable for controlling whether the server performs proxy user mapping for authentication plugins. | |
| collation_* | latin1_swedish_ci or utf8_general_ci | utf8mb4_0900_ai_ci | MySQL 8.0 defaults to the utf8mb4 character set. |
| column_compression_threshold | 100 | - | MariaDB supports Storage-engine Independent Column Compression. |
| column_compression_zlib_level | 6 | - | MariaDB supports Storage-engine Independent Column Compression. |
| column_compression_zlib_strategy | DEFAULT_STRATEGY | - | MariaDB supports Storage-engine Independent Column Compression. |
| column_compression_zlib_wrap | OFF | - | MariaDB supports Storage-engine Independent Column Compression. |
| cte_max_recursion_depth | - | 1000 | When MySQL 8.0 introduced common table expressions they used a different name. MariaDB's variable is called max_recursive_iterations. |
| date_format | %Y-%m-%d | - | Unused variable removed in MySQL 8.0 |
| datetime_format | %Y-%m-%d | - | Unused variable removed in MySQL 8.0 |
| deadlock_search_depth_long | 15 | - | The Aria storage engine is only available in MariaDB. |
| deadlock_search_depth_short | 4 | - | The Aria storage engine is only available in MariaDB. |
| deadlock_timeout_long | 50000000 | - | The Aria storage engine is only available in MariaDB. |
| deadlock_timeout_short | 10000 | - | The Aria storage engine is only available in MariaDB. |
| debug_no_thread_alarm | OFF | - | Disable system thread alarm calls, for debugging or testing. |
| default_authentication_plugin | - | caching_sha2_password | MySQL 8 introduced a new authentication plugin. |
| default_collation_for_utf8mb4 | - | utf8mb4_0900_ai_ci | For internal use in MySQL 8 replication. |
| default_master_connection | empty | - | For use with MariaDB's multi-source replication. |
| default_password_lifetime | 360 | MySQL-only variable determining how long passwords are valid for before expiring. | |
| default_regex_flags | empty | - | For handling incompatibilities between MariaDB's PCRE and the old regex library. |
| default_tmp_storage_engine | empty | InnoDB | Default storage engine used for tables created with CREATE TEMPORARY TABLE. |
| disabled_storage_engines | empty | MySQL-only variable for disabling specific storage engines. | |
| disconnect_on_expired_password | - | ON | MySQL permits passwords to be expired. |
| encrypt_binlog | OFF | - | MariaDB enables table and tablespace encryption. |
| encrypt_tmp_files | OFF | - | MariaDB enables table and tablespace encryption. |
| encrypt_tmp_disk_tables | OFF | - | MariaDB enables table and tablespace encryption. |
| end_markers_in_json | - | OFF | MySQL-only variable for adding end markers to JSON output. |
| enforce_gtid_consistency | - | OFF | MariaDB and MySQL have different GTID implementations. |
| enforce_storage_engine | none | Forces the use of a particular storage engine for new tables. | |
| eq_range_index_dive_limit | 0 | 200 | Variable for tuning when the optimizer should switch from using index dives to index statistics for qualifying rows estimation. |
| event_scheduler | OFF | ON | MySQL enables the event scheduler by default. |
| expensive_subquery_limit | 100 | - | Used for determining expensive queries for optimization. |
| explicit_defaults_for_timestamp | OFF | ON | MySQL 8 disables the old timestamp behavior. |
| extra_max_connections | 1 | - | Introduced in the MariaDB 5.1 threadpool. |
| extra_port | 0 | - | Introduced in the MariaDB 5.1 threadpool. |
| group_concat_max_len | 1048576 | 1024 | MariaDB increases the maximum length for a GROUP_CONCAT() result from 1K to 1M. |
| gtid_binlog_pos | empty | - | MariaDB and MySQL have different GTID implementations. |
| gtid_binlog_state | empty | - | MariaDB and MySQL have different GTID implementations. |
| gtid_current_pos | empty | - | MariaDB and MySQL have different GTID implementations. |
| gtid_domain_id | 0 | - | MariaDB and MySQL have different GTID implementations. |
| gtid_executed | - | empty | MariaDB and MySQL have different GTID implementations. |
| gtid_executed_compression_period | - | 1000 | MariaDB and MySQL have different GTID implementations. |
| gtid_ignore_duplicates | OFF | - | MariaDB and MySQL have different GTID implementations. |
| gtid_mode | - | OFF | MariaDB and MySQL have different GTID implementations. |
| gtid_next | - | AUTOMATIC | MariaDB and MySQL have different GTID implementations. |
| gtid_owned | - | empty | MariaDB and MySQL have different GTID implementations. |
| gtid_pos_auto_engines | empty | - | MariaDB and MySQL have different GTID implementations. |
| gtid_purged | - | empty | MariaDB and MySQL have different GTID implementations. |
| gtid_seq_no | 0 | - | MariaDB and MySQL have different GTID implementations. |
| gtid_slave_pos | empty | - | MariaDB and MySQL have different GTID implementations. |
| gtid_strict_mode | OFF | - | MariaDB and MySQL have different GTID implementations. |
| have_crypt | YES | - | MySQL has removed the ENCRYPT function. |
| have_openssl | MariaDB's version indicates whether YaSSL or openssl was used. MySQL's is a synonym for have_ssl. | ||
| have_query_cache | YES | - | MySQL has removed the query cache. |
| have_statement_timeout | - | Whether MySQL's statement execution timeout feature is available. | |
| have_symlink | YES | DISABLED | MySQL has removed symlink support. |
| histogram_generation_max_mem_size | - | 20000000 | Added when MySQL 8 introduced Histogram-based Statistics. MariaDB uses histogram_size |
| histogram_size | 0 | - | MariaDB introduced Histogram-based Statistics. |
| histogram_type | SINGLE_PREC_HB | - | MariaDB introduced Histogram-based Statistics. |
| idle_readonly_transaction_timeout | 0 | - | Time in seconds that the server waits for idle read-only transactions. |
| idle_transaction_timeout | 0 | - | Time in seconds that the server waits for idle transactions. |
| idle_write_transaction_timeout | 0 | - | Time in seconds that the server waits for idle write transactions. |
| ignore_builtin_innodb | OFF | - | Ignored and removed in MySQL 8. |
| in_transaction | 0 | - | Set to 1 if you are in a transaction, and 0 if not. |
| information_schema_stats_expiry | - | 86400 | Time until MySQL Information Schema cached statistics expire. |
| innodb_adaptive_flushing_lwm | 10.000000 | 10 | Adaptive flushing is enabled when this this low water mark percentage of the redo log capacity is reached. MariaDB's variable is a double, MySQL's an integer. |
| innodb_api_* | - | * | Specific to MySQL's memcached, removed in MariaDB 10.2. |
| innodb_autoinc_lock_mode | 1 | 2 | MariaDB has an extra mode, 3, for skipping the rollback of connected transactions. MySQL defaults to row-based replication, so can safely use 2. |
| innodb_background_* | * | - | MariaDB has support for data scrubbing. |
| innodb_checksums | ON | - | Deprecated option removed in MySQL. |
| innodb_compression_* | * | - | Introduced with MariaDB's InnoDB compression. |
| innodb_dedicated_server | - | OFF | MySQL option that automatically configures various settings if the server is a dedicated InnoDB database server. |
| innodb_default_encryption_key_id | 1 | - | Default encryption key id used for table encryption. See Data at Rest Encryption. |
| innodb_defragment | * | - | MariaDB can defragment InnoDB tablespaces. |
| innodb_directories | - | (empty) | Used to search for tablespace files when moving or restoring a new location. |
| innodb_disallow_writes | OFF | - | Tell InnoDB to stop any writes to disk. |
| innodb_encrypt_* | 1 | - | See MariaDB's Data at Rest Encryption. |
| innodb_fatal_semaphore_wait_threshold | 600 | - | MariaDB's fatal semaphore timeout is configurable. |
| innodb_flush_neighbors | 1 | 0 | MySQL 8 by default now assumes the use of an SSD device. |
| innodb_force_primary_key | OFF | - | If set to 1 in MariaDB (0 is default) CREATE TABLEs without a primary or unique key where all keyparts are NOT NULL will not be accepted, and will return an error. |
| innodb_idle_flush_pct | 100 | - | Up to what percentage of dirty pages in MariaDB should be flushed when InnoDB finds it has spare resources to do so. |
| innodb_immediate_scrub_data_uncompressed | OFF | - | MariaDB has support for data scrubbing. |
| innodb_lock_schedule_algorithm | VATS | - | MariaDB has an improved algorithm for deciding which of the waiting transactions should be granted a lock once it has been released. |
| innodb_locks_unsafe_for_binlog | OFF | - | Deprecated option in MariaDB for disabling gap locking for searches and index scans. Deprecated in MariaDB, use READ COMMITTED transaction isolation instead. |
| innodb_log_optimize_ddl | ON | - | Whether redo logging should be reduced when natively creating indexes or rebuilding tables |
| innodb_log_spin_* | - | * | MySQL variables for constraining CPU usage while waiting for flushed redo. |
| innodb_log_wait_for_flush_spin_hwm | - | * | MySQL variable for constraining CPU usage while waiting for flushed redo. |
| innodb_max_dirty_pages_pct | 75 | 90 | MySQL 8 increased the default to 90. |
| innodb_max_dirty_pages_pct_lwm | 0 | 10 | MySQL 8 increased the default to 10. |
| innodb_max_undo_log_size | 10485760 | 1073741824 | MariaDB 10.2 reduced the limit for when an undo tablespace is marked for truncation. |
| innodb_open_files | Autosized (2000) | Autosized (4000) | In most systems, autosized based on the table_open_cache setting, which differs between MariaDB and MySQL. |
| innodb_prefix_index_cluster_optimization | OFF | - | MariaDB includes the Facebook prefix index queries optimization. |
| innodb_print_ddl_logs | - | OFF | MySQL option for writing DDL logs to stderr. |
| innodb_redo_log_encrypt | - | OFF | MySQL 8 has also now introduced redo log encryption, but used a different name. The equivalent option in MariaDB is innodb_encrypt_log. |
| innodb_scrub_* | * | - | MariaDB includes options to scrub the redo log. |
| innodb_spin_wait_delay | 4 | 6 | MariaDB changed the default from 6 to 4 based on extensive benchmarking. |
| innodb_stats_modified_counter | 0 | - | MariaDB option to control the calculation of new statistics. |
| innodb_stats_sample_pages | 8 | - | Deprecated MariaDB option for control over index distribution statistics. |
| innodb_stats_traditional | ON | - | Enabling gives a larger sample of pages for larger tables for the purposes of index statistics calculation. |
| innodb_undo_log_encrypt | - | OFF | MySQL option for encrypting undo logs residing in separate undo tablespaces. |
| innodb_undo_log_truncate | OFF | ON | MySQL 8 changes the default to ON, marking larger undo logs for truncation. |
| innodb_undo_logs | 128 | - | Removed in MySQL 8. |
| innodb_undo_tablespaces | 0 | 2 | Number of tablespace files used for dividing up the undo logs. MySQL 8 has deprecated this setting, and increased the default (and minimum) to 2. |
| innodb_use_atomic_writes | ON | - | Atomic writes are a faster alternative to innodb_doublewrite and MariaDB automatically detects when supporting SSD cards are used. |
| internal_tmp_disk_storage_engine | - | INNODB | MySQL uses this variable to set the storage engine for on-disk internal temporary tables. |
| internal_tmp_mem_storage_engine | - | TEMPTABLE | MySQL and MariaDB use different formats for temporary tables. In MariaDB, the aria_used_for_temp_tables performs a similar function. |
| join_buffer_space_limit | 2097152 | - | Maximum size in bytes of the query buffer. See block-based join algorithms. |
| join_cache_level | 2 | - | For determining the join algorithms. See block-based join algorithms |
| key_buffer_size | 134217728 | 8388608 | Size of the buffer for the index blocks used by MyISAM tables and shared for all threads. |
| key_cache_file_hash_size | 512 | - | Number of hash buckets for open and changed files. |
| key_cache_segments | 0 | - | The number of segments in a key cache. See Segmented Key Cache. |
| keyring_operations | - | ON | Whether MySQL 8's keyring operations are enabled. |
| last_gtid | - | empty | MariaDB and MySQL have different GTID implementations. |
| local_infile | ON | OFF | MySQL no longer supports LOAD DATA LOCAL by default. |
| lock_wait_timeout | 86400 | 31536000 | MariaDB has reduced the timeout for acquiring metadata locks. |
| log_bin | OFF | ON | MySQL 8 enables the binary log by default. |
| log_bin_compress | OFF | - | MariaDB setting for whether or not the binary log can be compressed. |
| log_bin_compress_min_len | 256 | - | Minimum length of sql statement (in statement mode) or record (in row mode) that can be compressed. See Compressing Events to Reduce Size of the Binary Log. |
| log_bin_use_v1_row_events | - | OFF | MySQL-only variable showing whether or not MySQL's version 2 binary logging format is being used. |
| log_disabled_statements | sp | - | Disable logging of certain statements to the general log. |
| log_error_services | - | log_filter_internal; log_sink_internal | Components to enable for MySQL error logging. |
| log_error_verbosity | - | 3 | MySQL variable for setting verbosity of error, warning, and note messages in the error log. |
| log_slave_updates | OFF | ON | MySQL 8 has by default enabled binary logging of updates a slave receives from a master. |
| log_slow_admin_statements | ON | OFF | MariaDB logs slow admin statements to the slow query log by default. |
| log_slow_disabled_statements | admin,call,slave,sp | - | Disable logging of certain statements to the slow query log. |
| log_slow_filter | admin, filesort, filesort_on_disk, full_join, full_scan, query_cache, query_cache_miss, tmp_table, tmp_table_on_disk | - | For slow query log filtering. |
| log_slow_rate_limit | 1 | - | Limits the number of queries logged to the slow query log. |
| log_slow_slave_statements | ON | OFF | MariaDB logs slow slave statements to the slow query log by default. |
| log_slow_verbosity | empty | - | Controls information to be added to the slow query log. See also Slow Query Log Extended Statistics. |
| log_statements_unsafe_for_binlog | - | ON | MySQL setting for controlling whether binlog warnings are written to the error log. |
| log_syslog* | platform-dependent | - | MySQL variables with settings for writing to syslog. |
| log_tc_size | 24576 | - | Size in bytes of the transaction coordinator log, defined in multiples of 4096. |
| log_throttle_queries_not_using_indexes | - | 0 | MySQL-only variable for limiting the number of statements without indexes written to the slow query log. |
| log_timestamps | - | UTC | MySQL-only variable controlling the timezone for certain logging conditions. |
| log_warnings | 2 | - | MySQL 8 has replaced with log_error_verbosity. |
| mandatory_roles | - | (empty) | MySQL variable for assigning roles to all users. |
| master_info_repository | - | TABLE | Whether slave logs master status and connection info to a table or a file. |
| max_allowed_packet | 16M | 64M | |
| max_error_count | 64 | 1024 | Specifies the maximum number of messages stored for display by SHOW ERRORS and SHOW WARNINGS statements. |
| max_execution_time | - | 0 | MySQL renamed the max_statement_time variable. |
| max_length_for_sort_data | 64 | 1024 | 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 these are added to the sort key. This can speed up the sort as there's no need 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. |
| max_long_data_size | 16777216 | - | Maximum size for parameter values sent with mysql_stmt_send_long_data(). Removed in MySQL 5.6. |
| max_points_in_geometry | - | 65536 | Maximum points_per_circle for MySQL's ST_Buffer_Strategy() function. |
| max_recursive_iterations | 4294967295 | - | Maximum number of iterations when executing recursive queries. |
| max_relay_log_size | 1073741824 | 0 | Can be set by session in MariaDB. |
| max_seeks_for_key | 4294967295 | 4294967295 (32-bit) or 18446744073709547520 (64-bit) | 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. |
| max_session_mem_used | 9223372036854775807 | - | Amount of memory a single user session is allowed to allocate. |
| max_statement_time | 0 | - | Maximum time in seconds that a query can execute before being aborted. MySQL used to have a variable of this name before renaming it max_execution_time. |
| max_tmp_tables | 32 | - | Unused variable removed in MySQL. |
| max_write_lock_count | 4294967295 | 4294967295 (32-bit) or 18446744073709547520 (64-bit) | Read lock requests will be permitted for processing after this many write locks. |
| mrr_buffer_size | 262144 | - | Size of buffer to use when using multi-range read with range access. See Multi Range Read optimization. |
| multi_range_count | 1024 | - | Unused variable removed in MySQL. |
| myisam_block_size | 1024 | - | Block size used for MyISAM index pages. |
| myisam_recover_options | BACKUP,QUICK | OFF | MyISAM recovery mode. |
| myisam_sort_buffer_size | 134216704 | 8388608 | Size in bytes of the buffer allocated when creating or sorting indexes on a MyISAM table. |
| mysql_native_password_proxy_users | - | OFF | Whether MySQL's authentication plugin supports proxy users. I |
| mysql56_temporal_format | ON | Causes MariaDB to use the MySQL-5.6 low level formats for TIME, DATETIME and TIMESTAMP instead of the MariaDB 5.3+ version. | |
| new | - | OFF | Used for backward-compatibility with MySQL 4.1, not present in MariaDB. |
| mysqlx+* | - | * | MySQL's X plugin related variables. |
| ngram_token_size | - | 2 | Sets the n-gram token size for MySQL's n-gram full-text parser. |
| offline_mode | - | OFF | MySQL settting for specifying whether the server should run in offline mode. |
| old_alter_table | DEFAULT | OFF | From MariaDB 10.3, an alias for alter_algorithm. |
| old_mode | Empty string | - | Used for getting MariaDB to emulate behavior from an old version of MySQL or MariaDB. See OLD Mode. |
| old_passwords | OFF | - | MySQL 8 is no longer compatible with the old pre-MySQL 4.1 form of password hashing. |
| optimizer_selectivity_sampling_limit | 100 | - | Controls number of record samples to check condition selectivity. |
| optimizer_switch | See details | A series of flags for controlling the query optimizer. MariaDB has introduced a number of new settings. | |
| optimizer_trace_* | - | O* | MySQL-only variables for optimizer tracing. |
| optimizer_use_condition_selectivity | 1 | - | Controls which statistics can be used by the optimizer when looking for the best query execution plan. |
| original_commit_timestamp | - | * | Used by MySQL 8 for delaying replication. |
| parser_max_mem_size | - | 4294967295 (32-bit) or 18446744073709547520 (64-bit) | MySQL variable for limiting memory available to the parser. |
| password_* | - | * | Controls reuse of previous passwords in MySQL. |
| performance_schema | OFF | ON | The Performance Schema is off by default in MariaDB. |
| performance_schema_* | Many performance schema variables are autoset in MySQL, and MySQL has a different version, with additional variables. | ||
| plugin_maturity | One less than the server maturity | - | Minimum acceptable plugin maturity. |
| progress_report_time | 5 | - | Time in seconds between sending progress reports to the client for time-consuming statements. |
| proxy_protocol_networks | (empty) | - | Enable proxy protocol for these source networks. |
| query_alloc_block_size | 16384 | 8192 | Size in bytes of the extra blocks allocated during query parsing and execution (after query_prealloc_size is used up). |
| query_cache_* | * | - | MySQL has removed the query cache. |
| query_prealloc_size | 24576 | 8192 | Size in bytes of the persistent buffer for query parsing and execution, allocated on connect and freed on disconnect. |
| range_optimizer_max_mem_size | - | 8388608 | MySQL-only variable setting a limit on the range optimizer's memory usage. |
| rbr_exec_mode | - | STRICT | MySQL-only variable for determining the handling of certain key errors. |
| read_binlog_speed_limit | 0 | - | Permits restricting the speed at which the slave reads the binlog from the master. |
| regexp_* | - | * | Memory and time limits for regular expression matching operations. |
| relay_log_info_repository | - | TABLE | MySQL-only variable determining whether the slave's position in the relay logs is written to a file or table. |
| replicate_annotate_row_events | ON | - | Tells the slave to reproduce annotate_rows_events received from the master in its own binary log. |
| replicate_do_db | empty string | - | See Dynamic Replication Variables. |
| replicate_do_table | empty string | - | See Dynamic Replication Variables. |
| replicate_events_marked_for_skip | replicate | - | See Selectively skipping replication of binlog events. |
| replicate_ignore_db | empty string | - | See Dynamic Replication Variables. |
| replicate_ignore_table | empty string | - | See Dynamic Replication Variables. |
| replicate_wild_do_table | empty string | - | See Dynamic Replication Variables. |
| replicate_wild_ignore_table | empty string | - | See Dynamic Replication Variables. |
| require_secure_transport | - | OFF | MySQL-only variable determining whether client to server connections need to be secure. |
| result_metadata | - | FULL | Determine whether the server returns result set metadata for connections where this is optional. |
| rowid_merge_buff_size | 8388608 | - | See Non-semi-join subquery optimizations. |
| rpl_read_size | - | 8192 | Minimum data in bytes read from the binary and relay log files. |
| rpl_semi_sync_* | - | - | MariaDB 10.3 includes semisynchronous replication without the need to install a plugin. |
| rpl_stop_slave_timeout | - | 31536000 | Controls the time that STOP SLAVE waits before timing out. |
| schema_definition_cache | - | 256 | Limits the number of schema definition objects kept in the dictionary object cache. |
| secure_auth | ON | - | Removed in MySQL. |
| secure_timestamp | NO | - | MariaDB-only option permitting the restricting of direct setting of a session timestamp.. |
| server_id_bits | - | server_id | MySQL-only variable for use in MySQL Cluster. |
| server_uuid | - | UUID | MySQL-only variable containing the UUID. |
| session_track_gtids | - | OFF | MySQL-only variables for tracking gtid changes. MariaDB and MySQL's gtid implementation is different. |
| sha256_password_proxy_users | - | OFF | MySQL-only variable determining whether the sha256_password plugin supports proxy users. |
| show_create_table_verbosity | - | OFF | Option to cause SHOW CREATE TABLE to display ROW_FORMAT in all cases. |
| show_old_temporals | - | OFF | MySQL-only variable for determining whether SHOW CREATE TABLE output should include comments for old format temporal columns. |
| skip_parallel_replication | OFF | - | See parallel replication. |
| skip_replication | OFF | - | See Selectively skipping replication of binlog events. |
| slave_allow_batching | - | OFF | MySQL-only replication variable. |
| slave_checkpoint_group | - | 512 | MySQL-only replication variable. |
| slave_checkpoint_period | - | 300 | MySQL-only replication variable. |
| slave_ddl_exec_mode | IDEMPOTENT | - | Modes for how replication of DDL events should be executed. |
| slave_domain_parallel_threads | 0 | - | For configuring parallel replication. |
| slave_net_timeout | 3600 | 60 | MySQL reduced the timeout to 60s. |
| slave_parallel_max_queued | 131072 | - | For configuring parallel replication. |
| slave_parallel_mode | conservative | - | Controls what transactions are applied in parallel when using parallel_replication. |
| slave_parallel_threads | 0 | - | For configuring parallel replication. |
| slave_parallel_type | - | DATABASE | MySQL-only replication variable. |
| slave_pending_jobs_size_max | - | 16777216 | MySQL-only replication variable. |
| slave_preserve_commit_order | - | OFF | MySQL-only replication variable. |
| slave_rows_search_algorithms | - | INDEX_SCAN, HASH_SCAN | MySQL-only replication variable. |
| slave_run_triggers_for_rbr | NO | See Running triggers on the slave for Row-based events for a description and use-case for this setting. | |
| slave_transaction_retry_errors | 1213,1205 | - | When an error occurs during a transaction on the slave, replication usually halts. By default, transactions that caused a deadlock or elapsed lock wait timeout will be retried. One can add other errors to the the list of errors that should be retried by adding a comma-separated list of error numbers to this variable. |
| slave_transaction_retry_interval | 0 | - | Interval in seconds for the slave SQL thread to retry a failed transaction due to a deadlock, elapsed lock wait timeout or an error listed in slave_transaction_retry_errors. |
| sort_buffer_size | 2097152 | 262144 | The default sort buffer allocated has been reduced in MySQL. |
| sql_mode | STRICT_TRANS_TABLES, ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION | ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO, NO_ENGINE_SUBSTITUTION | See SQL Mode. |
| ssl_fips_mode | - | OFF | Whether FIPS mode is enabled on the server side. |
| standard_compliant_cte | ON | - | See Common Table Expressions. |
| storage_engine | InnoDB | - | Alias for default_storage_engine, removed in MySQL. |
| strict_password_validation | ON | - | In MariaDB, when password validation plugins are enabled, reject passwords that cannot be validated (passwords specified as a hash). |
| stored_program_definition_cache | - | 256 | Limits the number of stored program definition objects kept in the dictionary object cache. |
| super_read_only | - | OFF | MySQL variable for prohibiting client updates from users with the SUPER privilege. |
| sync_binlog | 0 | 1 | MySQL synchronizes all actions to the binary log before they are committed. |
| sync_frm | 1 | - | .frm files have been removed in MySQL. |
| system_versioning_alter_history | ERROR | - | MariaDB has System-Versioned Tables |
| system_versioning_asof | DEFAULT | - | MariaDB has System-Versioned Tables |
| table_definition_cache | 400 | -1 (autosized) | Number of table definitions that can be cached. |
| table_open_cache_instances | 8 | 16 | Maximum number of table cache instances. |
| tablespace_definition_cache | - | 256 | Limits the number of tablespace definition objects kept in the dictionary object cache. |
| tcp_keepalive_interval | 0 | - | Interval, in seconds, between when successive keep-alive packets are sent if no acknowledgement is received. |
| tcp_keepalive_probes | 0 | - | Number of unacknowledged probes to send before considering the connection dead and notifying the application layer. |
| tcp_keepalive_time | 0 | - | Timeout, in milliseconds, with no activity until the first TCP keep-alive packet is sent. |
| temptable_max_ram | - | 1GB | Limits the RAM used by MySQL's TempTable storage engine. |
| thread_cache_size | Autosized | -1 (autosized) | MariaDB uses an improved thread pool. |
| thread_concurrency | 10 | - | Removed in MySQL 5.7. |
| thread_pool_idle_timeout | 60 | - | See Using the Thread Pool. |
| thread_pool_max_threads | 65536 | - | See Using the Thread Pool. |
| thread_pool_min_threads | 1 | - | Windows-only. See Using the Thread Pool. |
| thread_pool_oversubscribe | 3 | - | See Using the Thread Pool. |
| thread_pool_prio_kickup | auto | - | See Using the Thread Pool. |
| thread_pool_priority | auto | - | See Using the Thread Pool. |
| thread_pool_size | Number of processors | 16* | See Using the Thread Pool. *Only available in MySQL with a commercial plugin. |
| thread_pool_stall_limit | 500 | 6* | See Using the Thread Pool. *Only available in MySQL with a commercial plugin. |
| thread_stack | 299008 | Varies | See Using the Thread Pool. |
| time_format | %H:%i:%s | - | Removed in MySQL. |
| timed_mutexes | OFF | - | Removed in MySQL. |
| tls_version | - | Varies | MySQL-only variable showing the permitted tls protocols. |
| tmp_disk_table_size | 18446744073709551615 | - | Max size for data for an internal temporary on-disk MyISAM or Aria table. |
| tmp_memory_table_size | 16777216 | - | Alias for tmp_table_size. |
| transaction_allow_batching | - | OFF | Variable for enabling batching of statements within the same transaction in MySQL Cluster. |
| transaction_isolation | - | REPEATABLE-READ | The MariaDB equivalent is tx_isolation. |
| transaction_read_only | - | OFF | The MariaDB equivalent is tx_read_only. |
| transaction_write_set_extraction | - | OFF | Unused MySQL-only variable. |
| tx_isolation | REPEATABLE-READ | - | The MySQL equivalent is transaction_isolation. |
| tx_read_only | OFF | - | The MySQL equivalent is transaction_read_only. |
| use_stat_tables | NEVER | - | Controls the use of engine-independent table statistics. |
| userstat | OFF | - | Whether to activate MariaDB's User Statistics implementation, not available in MySQL. |
| version_compile_zlib | - | * | Version of the zlib library compiled in. |
| version_malloc_library | * | - | Version of the used malloc library. |
| version_source_revision | Varies | - | Permits seeing exactly which version of the source was used for a build. |
| version_ssl_library | * | - | Version of the used TLS library. |
| windowing_high_use_precision | - | * | MySQL option allowing safety to be sacrificed for speed in window function calculations. |
| wsrep_* | * | - | Galera cluster is only available in MariaDB. |
| Variable | MariaDB 10.3 | MySQL 8.0 | Notes |
See Also
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