Table of Contents
MySQL Server (mysqld) is the main program that does most of the work in a MySQL installation. This chapter provides an overview of MySQL Server and covers general server administration:
Server configuration
The data directory, particularly the mysql
system database
The server log files
Management of multiple servers on a single machine
For additional information on administrative topics, see also:
mysqld is the MySQL server. The following discussion covers these MySQL server configuration topics:
Startup options that the server supports. You can specify these options on the command line, through configuration files, or both.
Server system variables. These variables reflect the current state and values of the startup options, some of which can be modified while the server is running.
Server status variables. These variables contain counters and statistics about runtime operation.
How to set the server SQL mode. This setting modifies certain aspects of SQL syntax and semantics, for example for compatibility with code from other database systems, or to control the error handling for particular situations.
Configuring and using IPv6 support.
Configuring and using time zone support.
Server-side help capabilities.
The server shutdown process. There are performance and reliability considerations depending on the type of table (transactional or nontransactional) and whether you use replication.
For listings of MySQL server variables and options that have been added, deprecated, or removed in MySQL 8.0, see Section 1.5, “Server and Status Variables and Options Added, Deprecated, or Removed in MySQL 8.0”.
Not all storage engines are supported by all MySQL server binaries and configurations. To find out how to determine which storage engines your MySQL server installation supports, see Section 13.7.6.16, “SHOW ENGINES Syntax”.
The MySQL server, mysqld, has many command options and system variables that can be set at startup to configure its operation. To determine the command option and system variable values used by the server, execute this command:
shell> mysqld --verbose --help
The command produces a list of all mysqld options and configurable system variables. Its output includes the default option and variable values and looks something like this:
abort-slave-event-count 0 allow-suspicious-udfs FALSE archive ON auto-increment-increment 1 auto-increment-offset 1 autocommit TRUE automatic-sp-privileges TRUE avoid-temporal-upgrade FALSE back-log 80 basedir /home/jon/bin/mysql-8.0/ ... tmpdir /tmp transaction-alloc-block-size 8192 transaction-isolation REPEATABLE-READ transaction-prealloc-size 4096 transaction-read-only FALSE transaction-write-set-extraction OFF updatable-views-with-limit YES validate-user-plugins TRUE verbose TRUE wait-timeout 28800
To see the current system variable values used by the server as it runs, connect to it and execute this statement:
mysql> SHOW VARIABLES;
To see some statistical and status indicators for a running server, execute this statement:
mysql> SHOW STATUS;
System variable and status information also is available using the mysqladmin command:
shell>mysqladmin variables
shell>mysqladmin extended-status
For a full description of all command options, system variables, and status variables, see these sections:
More detailed monitoring information is available from the Performance Schema; see Chapter 25, MySQL Performance Schema.
If you specify an option on the command line for mysqld or mysqld_safe, it remains in effect only for that invocation of the server. To use the option every time the server runs, put it in an option file. See Section 4.2.6, “Using Option Files”.
The MySQL server has many operating parameters, which you can change at server startup using command-line options or configuration files (option files). It is also possible to change many parameters at runtime. For general instructions on setting parameters at startup or runtime, see Section 5.1.6, “Server Command Options”, and Section 5.1.7, “Server System Variables”.
On Windows, MySQL Installer interacts with the user and creates a
file named my.ini
in the base installation
directory as the default option file.
On Windows, the .ini
or
.cnf
option file extension might not be
displayed.
After completing the installation process, you can edit the
default option file at any time to modify the parameters used by
the server. For example, to use a parameter setting in the file
that is commented with a #
character at the
beginning of the line, remove the #
, and modify
the parameter value if necessary. To disable a setting, either add
a #
to the beginning of the line or remove it.
For non-Windows platforms, no default option file is created during either the server installation or the data directory initialization process. Create your option file by following the instructions given in Section 4.2.6, “Using Option Files”. Without an option file, the server just starts with its default settings—see Section 5.1.2, “Server Configuration Defaults” on how to check those settings.
For additional information about option file format and syntax, see Section 4.2.6, “Using Option Files”.
The following table provides a list of all the command line
options, system variables, and status variables applicable within
mysqld
.
The table lists command-line options (Cmd-line), options valid in configuration files (Option file), server system variables (System Var), and status variables (Status var) in one unified list, with notification of where each option/variable is valid. If a server option set on the command line or in an option file differs from the name of the corresponding server system, the variable name is noted immediately below the corresponding option. For system and status variables, the scope of the variable is shown (Var Scope) as either global, session, or both. Please see the corresponding sections for details on setting and using the options and variables. Where appropriate, a direct link to further information on the item as available.
Table 5.1 Command-Line Option, System Variable, and Status Variable Summary
Notes:
1. This option is dynamic, but only the server should set this information. You should not set the value of this variable manually.
The following table provides a list of all the system variables
applicable within mysqld
.
The table lists command-line options (Cmd-line), options valid in configuration files (Option file), server system variables (System Var), and status variables (Status var) in one unified list, with notification of where each option/variable is valid. If a server option set on the command line or in an option file differs from the name of the corresponding server system, the variable name is noted immediately below the corresponding option. The scope of the variable is shown (Var Scope) as either global, session, or both. Please see the corresponding sections for details on setting and using the options and variables. Where appropriate, a direct link to further information on the item as available.
Table 5.2 System Variable Summary
Name | Cmd-Line | Option File | System Var | Var Scope | Dynamic |
---|---|---|---|---|---|
activate_all_roles_on_login | Yes | Yes | Yes | Global | Yes |
audit_log_buffer_size | Yes | Yes | Yes | Global | No |
audit_log_compression | Yes | Yes | Yes | Global | No |
audit_log_connection_policy | Yes | Yes | Yes | Global | Yes |
audit_log_current_session | Yes | Both | No | ||
audit_log_encryption | Yes | Yes | Yes | Global | No |
audit_log_exclude_accounts | Yes | Yes | Yes | Global | Yes |
audit_log_file | Yes | Yes | Yes | Global | No |
audit_log_filter_id | Yes | Both | No | ||
audit_log_flush | Yes | Global | Yes | ||
audit_log_format | Yes | Yes | Yes | Global | No |
audit_log_include_accounts | Yes | Yes | Yes | Global | Yes |
audit_log_policy | Yes | Yes | Yes | Global | No |
audit_log_read_buffer_size | Yes | Yes | Yes | Varies | Varies |
audit_log_rotate_on_size | Yes | Yes | Yes | Global | Yes |
audit_log_statement_policy | Yes | Yes | Yes | Global | Yes |
audit_log_strategy | Yes | Yes | Yes | Global | No |
authentication_ldap_sasl_auth_method_name | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_bind_base_dn | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_bind_root_dn | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_bind_root_pwd | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_ca_path | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_group_search_attr | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_group_search_filter | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_init_pool_size | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_log_status | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_max_pool_size | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_server_host | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_server_port | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_tls | Yes | Yes | Yes | Global | Yes |
authentication_ldap_sasl_user_search_attr | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_auth_method_name | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_bind_base_dn | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_bind_root_dn | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_bind_root_pwd | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_ca_path | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_group_search_attr | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_group_search_filter | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_init_pool_size | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_log_status | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_max_pool_size | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_server_host | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_server_port | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_tls | Yes | Yes | Yes | Global | Yes |
authentication_ldap_simple_user_search_attr | Yes | Yes | Yes | Global | Yes |
auto_generate_certs | Yes | Yes | Yes | Global | No |
auto_increment_increment | Yes | Both | Yes | ||
auto_increment_offset | Yes | Both | Yes | ||
autocommit | Yes | Yes | Yes | Both | Yes |
automatic_sp_privileges | Yes | Global | Yes | ||
avoid_temporal_upgrade | Yes | Yes | Yes | Global | Yes |
back_log | Yes | Global | No | ||
basedir | Yes | Yes | Yes | Global | No |
big-tables | Yes | Yes | Yes | ||
- Variable: big_tables | Yes | Both | Yes | ||
bind-address | Yes | Yes | No | ||
- Variable: bind_address | Yes | Global | No | ||
binlog_cache_size | Yes | Yes | Yes | Global | Yes |
binlog_checksum | Yes | Global | Yes | ||
binlog_direct_non_transactional_updates | Yes | Yes | Yes | Both | Yes |
binlog_error_action | Yes | Yes | Yes | Global | Yes |
binlog_expire_logs_seconds | Yes | Yes | Yes | Global | Yes |
binlog-format | Yes | Yes | Yes | ||
- Variable: binlog_format | Yes | Both | Yes | ||
binlog_group_commit_sync_delay | Yes | Yes | Yes | Global | Yes |
binlog_group_commit_sync_no_delay_count | Yes | Yes | Yes | Global | Yes |
binlog_gtid_simple_recovery | Yes | Yes | Yes | Global | No |
binlog_max_flush_queue_time | Yes | Global | Yes | ||
binlog_order_commits | Yes | Global | Yes | ||
binlog_row_image | Yes | Yes | Yes | Both | Yes |
binlog_row_metadata | Yes | Yes | Yes | Global | Yes |
binlog_row_value_options | Yes | Yes | Yes | Both | Yes |
binlog_rows_query_log_events | Yes | Yes | Yes | Both | Yes |
binlog_stmt_cache_size | Yes | Yes | Yes | Global | Yes |
binlog_transaction_dependency_history_size | Yes | Yes | Yes | Global | Yes |
binlog_transaction_dependency_tracking | Yes | Yes | Yes | Global | Yes |
block_encryption_mode | Yes | Yes | Yes | Both | Yes |
bulk_insert_buffer_size | Yes | Yes | Yes | Both | Yes |
caching_sha2_password_auto_generate_rsa_keys | Yes | Yes | Yes | Global | No |
caching_sha2_password_private_key_path | Yes | Yes | Yes | Global | No |
caching_sha2_password_public_key_path | Yes | Yes | Yes | Global | No |
character_set_client | Yes | Both | Yes | ||
character_set_connection | Yes | Both | Yes | ||
character_set_database (note 1) | Yes | Both | Yes | ||
character-set-filesystem | Yes | Yes | Yes | ||
- Variable: character_set_filesystem | Yes | Both | Yes | ||
character_set_results | Yes | Both | Yes | ||
character-set-server | Yes | Yes | Yes | ||
- Variable: character_set_server | Yes | Both | Yes | ||
character_set_system | Yes | Global | No | ||
character-sets-dir | Yes | Yes | No | ||
- Variable: character_sets_dir | Yes | Global | No | ||
check_proxy_users | Yes | Yes | Yes | Global | Yes |
collation_connection | Yes | Both | Yes | ||
collation_database (note 1) | Yes | Both | Yes | ||
collation-server | Yes | Yes | Yes | ||
- Variable: collation_server | Yes | Both | Yes | ||
completion_type | Yes | Yes | Yes | Both | Yes |
concurrent_insert | Yes | Yes | Yes | Global | Yes |
connect_timeout | Yes | Yes | Yes | Global | Yes |
connection_control_failed_connections_threshold | Yes | Yes | Yes | Global | Yes |
connection_control_max_connection_delay | Yes | Yes | Yes | Global | Yes |
connection_control_min_connection_delay | Yes | Yes | Yes | Global | Yes |
core_file | Yes | Global | No | ||
cte_max_recursion_depth | Yes | Yes | Yes | Both | Yes |
daemon_memcached_enable_binlog | Yes | Yes | Yes | Global | No |
daemon_memcached_engine_lib_name | Yes | Yes | Yes | Global | No |
daemon_memcached_engine_lib_path | Yes | Yes | Yes | Global | No |
daemon_memcached_option | Yes | Yes | Yes | Global | No |
daemon_memcached_r_batch_size | Yes | Yes | Yes | Global | No |
daemon_memcached_w_batch_size | Yes | Yes | Yes | Global | No |
datadir | Yes | Yes | Yes | Global | No |
date_format | Yes | Global | No | ||
datetime_format | Yes | Global | No | ||
debug | Yes | Yes | Yes | Both | Yes |
debug_sync | Yes | Session | Yes | ||
default_authentication_plugin | Yes | Yes | Yes | Global | No |
default_collation_for_utf8mb4 | Yes | Yes | Both | Yes | |
default_password_lifetime | Yes | Yes | Yes | Global | Yes |
default-storage-engine | Yes | Yes | Yes | ||
- Variable: default_storage_engine | Yes | Both | Yes | ||
default_tmp_storage_engine | Yes | Yes | Yes | Both | Yes |
default_week_format | Yes | Yes | Yes | Both | Yes |
delay-key-write | Yes | Yes | Yes | ||
- Variable: delay_key_write | Yes | Global | Yes | ||
delayed_insert_limit | Yes | Yes | Yes | Global | Yes |
delayed_insert_timeout | Yes | Yes | Yes | Global | Yes |
delayed_queue_size | Yes | Yes | Yes | Global | Yes |
disabled_storage_engines | Yes | Yes | Yes | Global | No |
disconnect_on_expired_password | Yes | Yes | Yes | Global | No |
div_precision_increment | Yes | Yes | Yes | Both | Yes |
dragnet.log_error_filter_rules | Yes | Yes | Yes | Global | Yes |
end_markers_in_json | Yes | Both | Yes | ||
enforce-gtid-consistency | Yes | Yes | Yes | Global | Yes |
enforce_gtid_consistency | Yes | Yes | Yes | Global | Yes |
eq_range_index_dive_limit | Yes | Both | Yes | ||
error_count | Yes | Session | No | ||
event-scheduler | Yes | Yes | Yes | ||
- Variable: event_scheduler | Yes | Global | Yes | ||
executed_gtids_compression_period | Yes | Global | Yes | ||
expire_logs_days | Yes | Yes | Yes | Global | Yes |
explicit_defaults_for_timestamp | Yes | Yes | Yes | Both | Yes |
external_user | Yes | Session | No | ||
flush | Yes | Yes | Yes | Global | Yes |
flush_time | Yes | Yes | Yes | Global | Yes |
foreign_key_checks | Yes | Both | Yes | ||
ft_boolean_syntax | Yes | Yes | Yes | Global | Yes |
ft_max_word_len | Yes | Yes | Yes | Global | No |
ft_min_word_len | Yes | Yes | Yes | Global | No |
ft_query_expansion_limit | Yes | Yes | Yes | Global | No |
ft_stopword_file | Yes | Yes | Yes | Global | No |
general-log | Yes | Yes | Yes | ||
- Variable: general_log | Yes | Global | Yes | ||
general_log_file | Yes | Yes | Yes | Global | Yes |
group_concat_max_len | Yes | Yes | Yes | Both | Yes |
group_replication_allow_local_disjoint_gtids_join | Yes | Yes | Yes | Global | Yes |
group_replication_allow_local_lower_version_join | Yes | Yes | Yes | Global | Yes |
group_replication_auto_increment_increment | Yes | Yes | Yes | Global | Yes |
group_replication_bootstrap_group | Yes | Yes | Yes | Global | Yes |
group_replication_communication_debug_options | Yes | Yes | Yes | Global | Yes |
group_replication_components_stop_timeout | Yes | Yes | Yes | Global | Yes |
group_replication_compression_threshold | Yes | Yes | Yes | Global | Yes |
group_replication_enforce_update_everywhere_checks | Yes | Yes | Yes | Global | Yes |
group_replication_exit_state_action | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_applier_threshold | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_certifier_threshold | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_hold_percent | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_max_commit_quota | Yes | Yes | Yes | ||
- Variable: group_replication_flow_control_min_quota | Yes | Global | Yes | ||
group_replication_flow_control_member_quota_percent | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_min_quota | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_min_recovery_quota | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_mode | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_period | Yes | Yes | Yes | Global | Yes |
group_replication_flow_control_release_percent | Yes | Yes | Yes | Global | Yes |
group_replication_force_members | Yes | Yes | Yes | Global | Yes |
group_replication_group_name | Yes | Yes | Yes | Global | Yes |
group_replication_group_seeds | Yes | Yes | Yes | Global | Yes |
group_replication_gtid_assignment_block_size | Yes | Yes | Yes | Global | Yes |
group_replication_ip_whitelist | Yes | Yes | Yes | Global | Yes |
group_replication_local_address | Yes | Yes | Yes | Global | Yes |
group_replication_member_weight | Yes | Yes | Yes | Global | Yes |
group_replication_poll_spin_loops | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_complete_at | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_get_public_key | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_public_key_path | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_reconnect_interval | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_retry_count | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_ca | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_capath | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_cert | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_cipher | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_crl | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_crlpath | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_key | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_ssl_verify_server_cert | Yes | Yes | Yes | Global | Yes |
group_replication_recovery_use_ssl | Yes | Yes | Yes | Global | Yes |
group_replication_single_primary_mode | Yes | Yes | Yes | Global | Yes |
group_replication_ssl_mode | Yes | Yes | Yes | Global | Yes |
group_replication_start_on_boot | Yes | Yes | Yes | Global | Yes |
group_replication_transaction_size_limit | Yes | Yes | Yes | Global | Yes |
group_replication_unreachable_majority_timeout | Yes | Yes | Yes | Global | Yes |
gtid_executed | Yes | Varies | No | ||
gtid_executed_compression_period | Yes | Global | Yes | ||
gtid-mode | Yes | Yes | Yes | ||
- Variable: gtid_mode | Yes | Global | Yes | ||
gtid_mode | Yes | Global | Yes | ||
gtid_next | Yes | Session | Yes | ||
gtid_owned | Yes | Both | No | ||
gtid_purged | Yes | Global | Yes | ||
have_compress | Yes | Global | No | ||
have_crypt | Yes | Global | No | ||
have_dynamic_loading | Yes | Global | No | ||
have_geometry | Yes | Global | No | ||
have_openssl | Yes | Global | No | ||
have_profiling | Yes | Global | No | ||
have_query_cache | Yes | Global | No | ||
have_rtree_keys | Yes | Global | No | ||
have_ssl | Yes | Global | No | ||
have_statement_timeout | Yes | Global | No | ||
have_symlink | Yes | Global | No | ||
histogram_generation_max_mem_size | Yes | Yes | Yes | Both | Yes |
host_cache_size | Yes | Global | Yes | ||
hostname | Yes | Global | No | ||
identity | Yes | Session | Yes | ||
ignore-builtin-innodb | Yes | Yes | No | ||
- Variable: ignore_builtin_innodb | Yes | Global | No | ||
information_schema_stats_expiry | Yes | Yes | Yes | Both | Yes |
init_connect | Yes | Yes | Yes | Global | Yes |
init-file | Yes | Yes | No | ||
- Variable: init_file | Yes | Global | No | ||
init_slave | Yes | Yes | Yes | Global | Yes |
innodb_adaptive_flushing | Yes | Yes | Yes | Global | Yes |
innodb_adaptive_flushing_lwm | Yes | Yes | Yes | Global | Yes |
innodb_adaptive_hash_index | Yes | Yes | Yes | Global | Yes |
innodb_adaptive_hash_index_parts | Yes | Yes | Yes | Global | No |
innodb_adaptive_max_sleep_delay | Yes | Yes | Yes | Global | Yes |
innodb_api_bk_commit_interval | Yes | Yes | Yes | Global | Yes |
innodb_api_disable_rowlock | Yes | Yes | Yes | Global | No |
innodb_api_enable_binlog | Yes | Yes | Yes | Global | No |
innodb_api_enable_mdl | Yes | Yes | Yes | Global | No |
innodb_api_trx_level | Yes | Yes | Yes | Global | Yes |
innodb_autoextend_increment | Yes | Yes | Yes | Global | Yes |
innodb_autoinc_lock_mode | Yes | Yes | Yes | Global | No |
innodb_background_drop_list_empty | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_chunk_size | Yes | Yes | Yes | Global | No |
innodb_buffer_pool_debug | Yes | Yes | Yes | Global | No |
innodb_buffer_pool_dump_at_shutdown | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_dump_now | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_dump_pct | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_filename | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_instances | Yes | Yes | Yes | Global | No |
innodb_buffer_pool_load_abort | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_load_at_startup | Yes | Yes | Yes | Global | No |
innodb_buffer_pool_load_now | Yes | Yes | Yes | Global | Yes |
innodb_buffer_pool_size | Yes | Yes | Yes | Global | Yes |
innodb_change_buffer_max_size | Yes | Yes | Yes | Global | Yes |
innodb_change_buffering | Yes | Yes | Yes | Global | Yes |
innodb_change_buffering_debug | Yes | Yes | Yes | Global | Yes |
innodb_checkpoint_disabled | Yes | Yes | Yes | Global | Yes |
innodb_checksum_algorithm | Yes | Yes | Yes | Global | Yes |
innodb_cmp_per_index_enabled | Yes | Yes | Yes | Global | Yes |
innodb_commit_concurrency | Yes | Yes | Yes | Global | Yes |
innodb_compress_debug | Yes | Yes | Yes | Global | Yes |
innodb_compression_failure_threshold_pct | Yes | Yes | Yes | Global | Yes |
innodb_compression_level | Yes | Yes | Yes | Global | Yes |
innodb_compression_pad_pct_max | Yes | Yes | Yes | Global | Yes |
innodb_concurrency_tickets | Yes | Yes | Yes | Global | Yes |
innodb_data_file_path | Yes | Yes | Yes | Global | No |
innodb_data_home_dir | Yes | Yes | Yes | Global | No |
innodb_ddl_log_crash_reset_debug | Yes | Yes | Yes | Global | Yes |
innodb_deadlock_detect | Yes | Yes | Yes | Global | Yes |
innodb_dedicated_server | Yes | Yes | Yes | Global | No |
innodb_default_row_format | Yes | Yes | Yes | Global | Yes |
innodb_directories | Yes | Yes | Yes | Global | No |
innodb_disable_sort_file_cache | Yes | Yes | Yes | Global | Yes |
innodb_doublewrite | Yes | Yes | Yes | Global | No |
innodb_fast_shutdown | Yes | Yes | Yes | Global | Yes |
innodb_fil_make_page_dirty_debug | Yes | Yes | Yes | Global | Yes |
innodb_file_per_table | Yes | Yes | Yes | Global | Yes |
innodb_fill_factor | Yes | Yes | Yes | Global | Yes |
innodb_flush_log_at_timeout | Yes | Global | Yes | ||
innodb_flush_log_at_trx_commit | Yes | Yes | Yes | Global | Yes |
innodb_flush_method | Yes | Yes | Yes | Global | No |
innodb_flush_neighbors | Yes | Yes | Yes | Global | Yes |
innodb_flush_sync | Yes | Yes | Yes | Global | Yes |
innodb_flushing_avg_loops | Yes | Yes | Yes | Global | Yes |
innodb_force_load_corrupted | Yes | Yes | Yes | Global | No |
innodb_force_recovery | Yes | Yes | Yes | Global | No |
innodb_fsync_threshold | Yes | Yes | Yes | Global | Yes |
innodb_ft_aux_table | Yes | Yes | Yes | Global | Yes |
innodb_ft_cache_size | Yes | Yes | Yes | Global | No |
innodb_ft_enable_diag_print | Yes | Yes | Yes | Global | Yes |
innodb_ft_enable_stopword | Yes | Yes | Yes | Global | Yes |
innodb_ft_max_token_size | Yes | Yes | Yes | Global | No |
innodb_ft_min_token_size | Yes | Yes | Yes | Global | No |
innodb_ft_num_word_optimize | Yes | Yes | Yes | Global | Yes |
innodb_ft_result_cache_limit | Yes | Yes | Yes | Global | Yes |
innodb_ft_server_stopword_table | Yes | Yes | Yes | Global | Yes |
innodb_ft_sort_pll_degree | Yes | Yes | Yes | Global | No |
innodb_ft_total_cache_size | Yes | Yes | Yes | Global | No |
innodb_ft_user_stopword_table | Yes | Yes | Yes | Both | Yes |
innodb_io_capacity | Yes | Yes | Yes | Global | Yes |
innodb_io_capacity_max | Yes | Yes | Yes | Global | Yes |
innodb_limit_optimistic_insert_debug | Yes | Yes | Yes | Global | Yes |
innodb_lock_wait_timeout | Yes | Yes | Yes | Both | Yes |
innodb_log_buffer_size | Yes | Yes | Yes | Global | Varies |
innodb_log_checksums | Yes | Yes | Yes | Global | Yes |
innodb_log_compressed_pages | Yes | Yes | Yes | Global | Yes |
innodb_log_file_size | Yes | Yes | Yes | Global | No |
innodb_log_files_in_group | Yes | Yes | Yes | Global | No |
innodb_log_group_home_dir | Yes | Yes | Yes | Global | No |
innodb_log_spin_cpu_abs_lwm | Yes | Yes | Yes | Global | Yes |
innodb_log_spin_cpu_pct_hwm | Yes | Yes | Yes | Global | Yes |
innodb_log_wait_for_flush_spin_hwm | Yes | Yes | Yes | Global | Yes |
innodb_log_write_ahead_size | Yes | Yes | Yes | Global | Yes |
innodb_lru_scan_depth | Yes | Yes | Yes | Global | Yes |
innodb_max_dirty_pages_pct | Yes | Yes | Yes | Global | Yes |
innodb_max_dirty_pages_pct_lwm | Yes | Yes | Yes | Global | Yes |
innodb_max_purge_lag | Yes | Yes | Yes | Global | Yes |
innodb_max_purge_lag_delay | Yes | Yes | Yes | Global | Yes |
innodb_max_undo_log_size | Yes | Yes | Yes | Global | Yes |
innodb_merge_threshold_set_all_debug | Yes | Yes | Yes | Global | Yes |
innodb_monitor_disable | Yes | Yes | Yes | Global | Yes |
innodb_monitor_enable | Yes | Yes | Yes | Global | Yes |
innodb_monitor_reset | Yes | Yes | Yes | Global | Yes |
innodb_monitor_reset_all | Yes | Yes | Yes | Global | Yes |
innodb_numa_interleave | Yes | Yes | Yes | Global | No |
innodb_old_blocks_pct | Yes | Yes | Yes | Global | Yes |
innodb_old_blocks_time | Yes | Yes | Yes | Global | Yes |
innodb_online_alter_log_max_size | Yes | Yes | Yes | Global | Yes |
innodb_open_files | Yes | Yes | Yes | Global | No |
innodb_optimize_fulltext_only | Yes | Yes | Yes | Global | Yes |
innodb_page_cleaners | Yes | Yes | Yes | Global | No |
innodb_page_size | Yes | Yes | Yes | Global | No |
innodb_print_all_deadlocks | Yes | Yes | Yes | Global | Yes |
innodb_print_ddl_logs | Yes | Yes | Yes | Global | Yes |
innodb_purge_batch_size | Yes | Yes | Yes | Global | Yes |
innodb_purge_rseg_truncate_frequency | Yes | Yes | Yes | Global | Yes |
innodb_purge_threads | Yes | Yes | Yes | Global | No |
innodb_random_read_ahead | Yes | Yes | Yes | Global | Yes |
innodb_read_ahead_threshold | Yes | Yes | Yes | Global | Yes |
innodb_read_io_threads | Yes | Yes | Yes | Global | No |
innodb_read_only | Yes | Yes | Yes | Global | No |
innodb_redo_log_encrypt | Yes | Yes | Yes | Global | Yes |
innodb_replication_delay | Yes | Yes | Yes | Global | Yes |
innodb_rollback_on_timeout | Yes | Yes | Yes | Global | No |
innodb_rollback_segments | Yes | Yes | Yes | Global | Yes |
innodb_saved_page_number_debug | Yes | Yes | Yes | Global | Yes |
innodb_scan_directories | Yes | Yes | Yes | Global | No |
innodb_sort_buffer_size | Yes | Yes | Yes | Global | No |
innodb_spin_wait_delay | Yes | Yes | Yes | Global | Yes |
innodb_stats_auto_recalc | Yes | Yes | Yes | Global | Yes |
innodb_stats_include_delete_marked | Yes | Yes | Yes | Global | Yes |
innodb_stats_method | Yes | Yes | Yes | Global | Yes |
innodb_stats_on_metadata | Yes | Yes | Yes | Global | Yes |
innodb_stats_persistent | Yes | Yes | Yes | Global | Yes |
innodb_stats_persistent_sample_pages | Yes | Yes | Yes | Global | Yes |
innodb_stats_transient_sample_pages | Yes | Yes | Yes | Global | Yes |
innodb_status_output | Yes | Yes | Yes | Global | Yes |
innodb_status_output_locks | Yes | Yes | Yes | Global | Yes |
innodb_strict_mode | Yes | Yes | Yes | Both | Yes |
innodb_sync_array_size | Yes | Yes | Yes | Global | No |
innodb_sync_debug | Yes | Yes | Yes | Global | No |
innodb_sync_spin_loops | Yes | Yes | Yes | Global | Yes |
innodb_table_locks | Yes | Yes | Yes | Both | Yes |
innodb_temp_data_file_path | Yes | Yes | Yes | Global | No |
innodb_temp_tablespaces_dir | Yes | Yes | Yes | Global | No |
innodb_thread_concurrency | Yes | Yes | Yes | Global | Yes |
innodb_thread_sleep_delay | Yes | Yes | Yes | Global | Yes |
innodb_tmpdir | Yes | Yes | Yes | Both | Yes |
innodb_trx_purge_view_update_only_debug | Yes | Yes | Yes | Global | Yes |
innodb_trx_rseg_n_slots_debug | Yes | Yes | Yes | Global | Yes |
innodb_undo_directory | Yes | Yes | Yes | Global | No |
innodb_undo_log_encrypt | Yes | Yes | Yes | Global | Yes |
innodb_undo_log_truncate | Yes | Yes | Yes | Global | Yes |
innodb_undo_logs | Yes | Yes | Yes | Global | Yes |
innodb_undo_tablespaces | Yes | Yes | Yes | Global | Varies |
innodb_use_native_aio | Yes | Yes | Yes | Global | No |
innodb_version | Yes | Global | No | ||
innodb_write_io_threads | Yes | Yes | Yes | Global | No |
insert_id | Yes | Session | Yes | ||
interactive_timeout | Yes | Yes | Yes | Both | Yes |
internal_tmp_disk_storage_engine | Yes | Yes | Yes | Global | Yes |
internal_tmp_mem_storage_engine | Yes | Yes | Yes | Both | Yes |
join_buffer_size | Yes | Yes | Yes | Both | Yes |
keep_files_on_create | Yes | Yes | Yes | Both | Yes |
key_buffer_size | Yes | Yes | Yes | Global | Yes |
key_cache_age_threshold | Yes | Yes | Yes | Global | Yes |
key_cache_block_size | Yes | Yes | Yes | Global | Yes |
key_cache_division_limit | Yes | Yes | Yes | Global | Yes |
keyring_aws_cmk_id | Yes | Yes | Yes | Global | Yes |
keyring_aws_conf_file | Yes | Yes | Yes | Global | No |
keyring_aws_data_file | Yes | Yes | Yes | Global | No |
keyring_aws_region | Yes | Yes | Yes | Global | Yes |
keyring_encrypted_file_data | Yes | Yes | Yes | Global | Yes |
keyring_encrypted_file_password | Yes | Yes | Yes | Global | Yes |
keyring_file_data | Yes | Yes | Yes | Global | Yes |
keyring_okv_conf_dir | Yes | Yes | Yes | Global | Yes |
keyring_operations | Yes | Global | Yes | ||
language | Yes | Yes | Yes | Global | No |
large_files_support | Yes | Global | No | ||
large_page_size | Yes | Global | No | ||
large-pages | Yes | Yes | No | ||
- Variable: large_pages | Yes | Global | No | ||
last_insert_id | Yes | Session | Yes | ||
lc-messages | Yes | Yes | Yes | ||
- Variable: lc_messages | Yes | Both | Yes | ||
lc-messages-dir | Yes | Yes | No | ||
- Variable: lc_messages_dir | Yes | Global | No | ||
lc_time_names | Yes | Both | Yes | ||
license | Yes | Global | No | ||
local_infile | Yes | Global | Yes | ||
lock_wait_timeout | Yes | Yes | Yes | Both | Yes |
locked_in_memory | Yes | Global | No | ||
log-bin | Yes | Yes | Yes | Global | No |
log_bin | Yes | Global | No | ||
log_bin_basename | Yes | Global | No | ||
log_bin_index | Yes | Global | No | ||
log-bin-trust-function-creators | Yes | Yes | Yes | ||
- Variable: log_bin_trust_function_creators | Yes | Global | Yes | ||
log-bin-use-v1-row-events | Yes | Yes | No | ||
- Variable: log_bin_use_v1_row_events | Yes | Global | No | ||
log_bin_use_v1_row_events | Yes | Yes | Yes | Global | No |
log_builtin_as_identified_by_password | Yes | Yes | Yes | Global | Yes |
log-error | Yes | Yes | No | ||
- Variable: log_error | Yes | Global | No | ||
log_error_filter_rules | Yes | Yes | Yes | Global | Yes |
log_error_services | Yes | Yes | Yes | Global | Yes |
log_error_suppression_list | Yes | Yes | Yes | Global | Yes |
log_error_verbosity | Yes | Yes | Yes | Global | Yes |
log-output | Yes | Yes | Yes | ||
- Variable: log_output | Yes | Global | Yes | ||
log-queries-not-using-indexes | Yes | Yes | Yes | ||
- Variable: log_queries_not_using_indexes | Yes | Global | Yes | ||
log-slave-updates | Yes | Yes | No | ||
- Variable: log_slave_updates | Yes | Global | No | ||
log_slave_updates | Yes | Yes | Yes | Global | No |
log_slow_admin_statements | Yes | Global | Yes | ||
log_slow_slave_statements | Yes | Global | Yes | ||
log_statements_unsafe_for_binlog | Yes | Global | Yes | ||
log_syslog | Yes | Yes | Yes | Global | Yes |
log_syslog_facility | Yes | Yes | Yes | Global | Yes |
log_syslog_include_pid | Yes | Yes | Yes | Global | Yes |
log_syslog_tag | Yes | Yes | Yes | Global | Yes |
log_throttle_queries_not_using_indexes | Yes | Global | Yes | ||
log_timestamps | Yes | Yes | Yes | Global | Yes |
log-warnings | Yes | Yes | Yes | ||
- Variable: log_warnings | Yes | Global | Yes | ||
long_query_time | Yes | Yes | Yes | Both | Yes |
low-priority-updates | Yes | Yes | Yes | ||
- Variable: low_priority_updates | Yes | Both | Yes | ||
lower_case_file_system | Yes | Global | No | ||
lower_case_table_names | Yes | Yes | Yes | Global | No |
mandatory_roles | Yes | Yes | Yes | Global | Yes |
master_info_repository | Yes | Yes | Yes | Global | Yes |
master_verify_checksum | Yes | Global | Yes | ||
max_allowed_packet | Yes | Yes | Yes | Both | Yes |
max_binlog_cache_size | Yes | Yes | Yes | Global | Yes |
max_binlog_size | Yes | Yes | Yes | Global | Yes |
max_binlog_stmt_cache_size | Yes | Yes | Yes | Global | Yes |
max_connect_errors | Yes | Yes | Yes | Global | Yes |
max_connections | Yes | Yes | Yes | Global | Yes |
max_delayed_threads | Yes | Yes | Yes | Both | Yes |
max_digest_length | Yes | Yes | Yes | Global | No |
max_error_count | Yes | Yes | Yes | Both | Yes |
max_execution_time | Yes | Yes | Yes | Both | Yes |
max_heap_table_size | Yes | Yes | Yes | Both | Yes |
max_insert_delayed_threads | Yes | Both | Yes | ||
max_join_size | Yes | Yes | Yes | Both | Yes |
max_length_for_sort_data | Yes | Yes | Yes | Both | Yes |
max_points_in_geometry | Yes | Yes | Yes | Both | Yes |
max_prepared_stmt_count | Yes | Yes | Yes | Global | Yes |
max_relay_log_size | Yes | Yes | Yes | Global | Yes |
max_seeks_for_key | Yes | Yes | Yes | Both | Yes |
max_sort_length | Yes | Yes | Yes | Both | Yes |
max_sp_recursion_depth | Yes | Yes | Yes | Both | Yes |
max_tmp_tables | Yes | Both | Yes | ||
max_user_connections | Yes | Yes | Yes | Both | Yes |
max_write_lock_count | Yes | Yes | Yes | Global | Yes |
mecab_rc_file | Yes | Yes | Yes | Global | No |
metadata_locks_cache_size | Yes | Global | No | ||
metadata_locks_hash_instances | Yes | Global | No | ||
min-examined-row-limit | Yes | Yes | Yes | Both | Yes |
multi_range_count | Yes | Yes | Yes | Both | Yes |
myisam_data_pointer_size | Yes | Yes | Yes | Global | Yes |
myisam_max_sort_file_size | Yes | Yes | Yes | Global | Yes |
myisam_mmap_size | Yes | Yes | Yes | Global | No |
myisam_recover_options | Yes | Global | No | ||
myisam_repair_threads | Yes | Yes | Yes | Both | Yes |
myisam_sort_buffer_size | Yes | Yes | Yes | Both | Yes |
myisam_stats_method | Yes | Yes | Yes | Both | Yes |
myisam_use_mmap | Yes | Yes | Yes | Global | Yes |
mysql_firewall_mode | Yes | Yes | Yes | Global | Yes |
mysql_firewall_trace | Yes | Yes | Yes | Global | Yes |
mysql_native_password_proxy_users | Yes | Yes | Yes | Global | Yes |
mysqlx | Yes | Yes | Yes | Global | No |
mysqlx-bind-address | Yes | Yes | Yes | Global | No |
mysqlx_bind_address | Yes | Yes | Yes | Global | No |
mysqlx-connect-timeout | Yes | Yes | Yes | Global | Yes |
mysqlx_connect_timeout | Yes | Yes | Yes | Global | Yes |
mysqlx_document_id_unique_prefix | Yes | Yes | Yes | Global | Yes |
mysqlx-idle-worker-thread-timeout | Yes | Yes | Yes | Global | Yes |
mysqlx_idle_worker_thread_timeout | Yes | Yes | Yes | Global | Yes |
mysqlx-interactive-timeout | Yes | Yes | Yes | Global | Yes |
mysqlx_interactive_timeout | Yes | Yes | Yes | Global | Yes |
mysqlx-max-allowed-packet | Yes | Yes | Yes | Global | Yes |
mysqlx_max_allowed_packet | Yes | Yes | Yes | Global | Yes |
mysqlx-max-connections | Yes | Yes | Yes | Global | Yes |
mysqlx_max_connections | Yes | Yes | Yes | Global | Yes |
mysqlx-min-worker-threads | Yes | Yes | Yes | Global | Yes |
mysqlx_min_worker_threads | Yes | Yes | Yes | Global | Yes |
mysqlx-port | Yes | Yes | Yes | Global | No |
mysqlx_port | Yes | Yes | Yes | Global | No |
mysqlx-port-open-timeout | Yes | Yes | Yes | Global | No |
mysqlx_port_open_timeout | Yes | Yes | Yes | Global | No |
mysqlx-read-timeout | Yes | Yes | Yes | Session | Yes |
mysqlx_read_timeout | Yes | Yes | Yes | Session | Yes |
mysqlx-socket | Yes | Yes | Yes | Global | No |
mysqlx_socket | Yes | Yes | Yes | Global | No |
mysqlx-ssl-ca | Yes | Yes | Yes | Global | No |
mysqlx-ssl-capath | Yes | Yes | Yes | Global | No |
mysqlx-ssl-cert | Yes | Yes | Yes | Global | No |
mysqlx-ssl-crl | Yes | Yes | Yes | Global | No |
mysqlx-ssl-crlpath | Yes | Yes | Yes | Global | No |
mysqlx-ssl-key | Yes | Yes | Yes | Global | No |
mysqlx-wait-timeout | Yes | Yes | Yes | Session | Yes |
mysqlx_wait_timeout | Yes | Yes | Yes | Session | Yes |
mysqlx-write-timeout | Yes | Yes | Yes | Session | Yes |
mysqlx_write_timeout | Yes | Yes | Yes | Session | Yes |
named_pipe | Yes | Global | No | ||
ndb-batch-size | Yes | Yes | Yes | Global | No |
ndb-blob-write-batch-bytes | Yes | Yes | Yes | Both | Yes |
ndb-cluster-connection-pool | Yes | Yes | Yes | Global | No |
ndb-cluster-connection-pool-nodeids | Yes | Yes | Yes | Global | No |
ndb-deferred-constraints | Yes | Yes | Yes | ||
- Variable: ndb_deferred_constraints | Yes | Both | Yes | ||
ndb_deferred_constraints | Yes | Yes | Yes | Both | Yes |
ndb-distribution | Yes | Yes | Yes | ||
- Variable: ndb_distribution | Yes | Global | Yes | ||
ndb_distribution | Yes | Yes | Yes | Global | Yes |
ndb_eventbuffer_free_percent | Yes | Yes | Yes | Global | Yes |
ndb_eventbuffer_max_alloc | Yes | Yes | Yes | Global | Yes |
ndb_force_send | Yes | Yes | Yes | Both | Yes |
ndb_index_stat_enable | Yes | Yes | Yes | Both | Yes |
ndb_index_stat_option | Yes | Yes | Yes | Both | Yes |
ndb_join_pushdown | Yes | Both | Yes | ||
ndb-log-apply-status | Yes | Yes | No | ||
- Variable: ndb_log_apply_status | Yes | Global | No | ||
ndb_log_apply_status | Yes | Yes | Yes | Global | No |
ndb_log_binlog_index | Yes | Yes | Global | Yes | |
ndb-log-empty-epochs | Yes | Yes | Yes | Global | Yes |
ndb-log-empty-update | Yes | Yes | Yes | Global | Yes |
ndb-log-transaction-id | Yes | Yes | No | ||
- Variable: ndb_log_transaction_id | Yes | Global | No | ||
ndb_log_updated_only | Yes | Yes | Yes | Global | Yes |
ndb_optimization_delay | Yes | Global | Yes | ||
ndb_optimized_node_selection | Yes | Yes | Yes | Global | No |
ndb_recv_thread_cpu_mask | Yes | Global | Yes | ||
ndb_report_thresh_binlog_epoch_slip | Yes | Yes | Yes | Global | Yes |
ndb_report_thresh_binlog_mem_usage | Yes | Yes | Yes | Global | Yes |
ndb_show_foreign_key_mock_tables | Yes | Yes | Yes | Global | Yes |
Ndb_slave_max_replicated_epoch | Yes | Global | No | ||
ndb_table_no_logging | Yes | Session | Yes | ||
ndb_use_transactions | Yes | Yes | Yes | Both | Yes |
ndb_version | Yes | Global | No | ||
ndb_version_string | Yes | Global | No | ||
ndb-wait-setup | Yes | Yes | Yes | Global | No |
ndbinfo_database | Yes | Global | No | ||
ndbinfo_max_rows | Yes | Yes | Both | Yes | |
ndbinfo_show_hidden | Yes | Yes | Both | Yes | |
ndbinfo_version | Yes | Global | No | ||
net_buffer_length | Yes | Yes | Yes | Both | Yes |
net_read_timeout | Yes | Yes | Yes | Both | Yes |
net_retry_count | Yes | Yes | Yes | Both | Yes |
net_write_timeout | Yes | Yes | Yes | Both | Yes |
new | Yes | Yes | Yes | Both | Yes |
ngram_token_size | Yes | Yes | Yes | Global | No |
offline_mode | Yes | Yes | Yes | Global | Yes |
old | Yes | Yes | Yes | Global | No |
old-alter-table | Yes | Yes | Yes | ||
- Variable: old_alter_table | Yes | Both | Yes | ||
old_passwords | Yes | Both | Yes | ||
open-files-limit | Yes | Yes | No | ||
- Variable: open_files_limit | Yes | Global | No | ||
optimizer_prune_level | Yes | Yes | Yes | Both | Yes |
optimizer_search_depth | Yes | Yes | Yes | Both | Yes |
optimizer_switch | Yes | Yes | Yes | Both | Yes |
optimizer_trace | Yes | Both | Yes | ||
optimizer_trace_features | Yes | Both | Yes | ||
optimizer_trace_limit | Yes | Both | Yes | ||
optimizer_trace_max_mem_size | Yes | Both | Yes | ||
optimizer_trace_offset | Yes | Both | Yes | ||
parser_max_mem_size | Yes | Yes | Yes | Both | Yes |
password_history | Yes | Yes | Yes | Global | Yes |
password_require_current | Yes | Yes | Yes | Global | Yes |
password_reuse_interval | Yes | Yes | Yes | Global | Yes |
performance_schema | Yes | Yes | Yes | Global | No |
performance_schema_accounts_size | Yes | Yes | Yes | Global | No |
performance_schema_digests_size | Yes | Yes | Yes | Global | No |
performance_schema_error_size | Yes | Yes | Yes | Global | No |
performance_schema_events_stages_history_long_size | Yes | Yes | Yes | Global | No |
performance_schema_events_stages_history_size | Yes | Yes | Yes | Global | No |
performance_schema_events_statements_history_long_size | Yes | Yes | Yes | Global | No |
performance_schema_events_statements_history_size | Yes | Yes | Yes | Global | No |
performance_schema_events_transactions_history_long_size | Yes | Yes | Yes | Global | No |
performance_schema_events_transactions_history_size | Yes | Yes | Yes | Global | No |
performance_schema_events_waits_history_long_size | Yes | Yes | Yes | Global | No |
performance_schema_events_waits_history_size | Yes | Yes | Yes | Global | No |
performance_schema_hosts_size | Yes | Yes | Yes | Global | No |
performance_schema_max_cond_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_cond_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_digest_length | Yes | Yes | Yes | Global | No |
performance_schema_max_digest_sample_age | Yes | Yes | Yes | Global | Yes |
performance_schema_max_file_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_file_handles | Yes | Yes | Yes | Global | No |
performance_schema_max_file_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_index_stat | Yes | Yes | Yes | Global | No |
performance_schema_max_memory_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_metadata_locks | Yes | Yes | Yes | Global | No |
performance_schema_max_mutex_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_mutex_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_prepared_statements_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_program_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_rwlock_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_rwlock_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_socket_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_socket_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_sql_text_length | Yes | Yes | Yes | Global | No |
performance_schema_max_stage_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_statement_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_statement_stack | Yes | Yes | Yes | Global | No |
performance_schema_max_table_handles | Yes | Yes | Yes | Global | No |
performance_schema_max_table_instances | Yes | Yes | Yes | Global | No |
performance_schema_max_table_lock_stat | Yes | Yes | Yes | Global | No |
performance_schema_max_thread_classes | Yes | Yes | Yes | Global | No |
performance_schema_max_thread_instances | Yes | Yes | Yes | Global | No |
performance_schema_session_connect_attrs_size | Yes | Yes | Yes | Global | No |
performance_schema_setup_actors_size | Yes | Yes | Yes | Global | No |
performance_schema_setup_objects_size | Yes | Yes | Yes | Global | No |
performance_schema_users_size | Yes | Yes | Yes | Global | No |
persisted_globals_load | Yes | Yes | Yes | Global | No |
pid-file | Yes | Yes | No | ||
- Variable: pid_file | Yes | Global | No | ||
plugin_dir | Yes | Yes | Yes | Global | No |
port | Yes | Yes | Yes | Global | No |
preload_buffer_size | Yes | Yes | Yes | Both | Yes |
profiling | Yes | Both | Yes | ||
profiling_history_size | Yes | Yes | Yes | Both | Yes |
protocol_version | Yes | Global | No | ||
proxy_user | Yes | Session | No | ||
pseudo_slave_mode | Yes | Session | Yes | ||
pseudo_thread_id | Yes | Session | Yes | ||
query_alloc_block_size | Yes | Yes | Yes | Both | Yes |
query_cache_limit | Yes | Yes | Yes | Global | Yes |
query_cache_min_res_unit | Yes | Yes | Yes | Global | Yes |
query_cache_size | Yes | Yes | Yes | Global | Yes |
query_cache_type | Yes | Yes | Yes | Both | Yes |
query_cache_wlock_invalidate | Yes | Yes | Yes | Both | Yes |
query_prealloc_size | Yes | Yes | Yes | Both | Yes |
rand_seed1 | Yes | Session | Yes | ||
rand_seed2 | Yes | Session | Yes | ||
range_alloc_block_size | Yes | Yes | Yes | Both | Yes |
range_optimizer_max_mem_size | Yes | Yes | Yes | Both | Yes |
rbr_exec_mode | Yes | Both | Yes | ||
read_buffer_size | Yes | Yes | Yes | Both | Yes |
read_only | Yes | Yes | Yes | Global | Yes |
read_rnd_buffer_size | Yes | Yes | Yes | Both | Yes |
regexp_stack_limit | Yes | Yes | Yes | Global | Yes |
regexp_time_limit | Yes | Yes | Yes | Global | Yes |
relay-log | Yes | Yes | No | ||
- Variable: relay_log | Yes | Global | No | ||
relay_log_basename | Yes | Global | No | ||
relay-log-index | Yes | Yes | No | ||
- Variable: relay_log_index | Yes | Global | No | ||
relay_log_index | Yes | Yes | Yes | Global | No |
relay_log_info_file | Yes | Yes | Yes | Global | No |
relay_log_info_repository | Yes | Global | Yes | ||
relay_log_purge | Yes | Yes | Yes | Global | Yes |
relay_log_recovery | Yes | Yes | Yes | Global | No |
relay_log_space_limit | Yes | Yes | Yes | Global | No |
report-host | Yes | Yes | No | ||
- Variable: report_host | Yes | Global | No | ||
report-password | Yes | Yes | No | ||
- Variable: report_password | Yes | Global | No | ||
report-port | Yes | Yes | No | ||
- Variable: report_port | Yes | Global | No | ||
report-user | Yes | Yes | No | ||
- Variable: report_user | Yes | Global | No | ||
require_secure_transport | Yes | Yes | Yes | Global | Yes |
resultset_metadata | Yes | Session | Yes | ||
rewriter_enabled | Yes | Global | Yes | ||
rewriter_verbose | Yes | Global | Yes | ||
rpl_read_size | Yes | Yes | Yes | Global | Yes |
rpl_semi_sync_master_enabled | Yes | Global | Yes | ||
rpl_semi_sync_master_timeout | Yes | Global | Yes | ||
rpl_semi_sync_master_trace_level | Yes | Global | Yes | ||
rpl_semi_sync_master_wait_for_slave_count | Yes | Global | Yes | ||
rpl_semi_sync_master_wait_no_slave | Yes | Global | Yes | ||
rpl_semi_sync_master_wait_point | Yes | Global | Yes | ||
rpl_semi_sync_slave_enabled | Yes | Global | Yes | ||
rpl_semi_sync_slave_trace_level | Yes | Global | Yes | ||
rpl_stop_slave_timeout | Yes | Yes | Yes | Global | Yes |
schema_definition_cache | Yes | Yes | Yes | Global | Yes |
secure-auth | Yes | Yes | Yes | ||
- Variable: secure_auth | Yes | Global | Yes | ||
secure-file-priv | Yes | Yes | No | ||
- Variable: secure_file_priv | Yes | Global | No | ||
server-id | Yes | Yes | Yes | ||
- Variable: server_id | Yes | Global | Yes | ||
server_uuid | Yes | Global | No | ||
session_track_gtids | Yes | Yes | Yes | Both | Yes |
session_track_schema | Yes | Yes | Yes | Both | Yes |
session_track_state_change | Yes | Yes | Yes | Both | Yes |
session_track_system_variables | Yes | Yes | Yes | Both | Yes |
sha256_password_auto_generate_rsa_keys | Yes | Yes | Yes | Global | No |
sha256_password_private_key_path | Yes | Yes | Yes | Global | No |
sha256_password_proxy_users | Yes | Yes | Yes | Global | Yes |
sha256_password_public_key_path | Yes | Yes | Yes | Global | No |
shared_memory | Yes | Yes | Yes | Global | No |
shared_memory_base_name | Yes | Yes | Yes | Global | No |
show_compatibility_56 | Yes | Yes | Yes | Global | Yes |
show_create_table_verbosity | Yes | Yes | Yes | Both | Yes |
show_old_temporals | Yes | Yes | Yes | Both | Yes |
simplified_binlog_gtid_recovery | Yes | Yes | Yes | Global | No |
skip_external_locking | Yes | Yes | Yes | Global | No |
skip-name-resolve | Yes | Yes | No | ||
- Variable: skip_name_resolve | Yes | Global | No | ||
skip-networking | Yes | Yes | No | ||
- Variable: skip_networking | Yes | Global | No | ||
skip-show-database | Yes | Yes | No | ||
- Variable: skip_show_database | Yes | Global | No | ||
slave_allow_batching | Yes | Yes | Yes | Global | Yes |
slave_checkpoint_group | Yes | Yes | Yes | Global | Yes |
slave_checkpoint_period | Yes | Yes | Yes | Global | Yes |
slave_compressed_protocol | Yes | Yes | Yes | Global | Yes |
slave_exec_mode | Yes | Yes | Yes | Global | Yes |
slave-load-tmpdir | Yes | Yes | No | ||
- Variable: slave_load_tmpdir | Yes | Global | No | ||
slave_max_allowed_packet | Yes | Global | Yes | ||
slave-net-timeout | Yes | Yes | Yes | ||
- Variable: slave_net_timeout | Yes | Global | Yes | ||
slave_parallel_type | Yes | Global | Yes | ||
slave_parallel_workers | Yes | Yes | Global | Yes | |
slave_pending_jobs_size_max | Yes | Yes | Global | Yes | |
slave_preserve_commit_order | Yes | Yes | Global | Yes | |
slave_rows_search_algorithms | Yes | Global | Yes | ||
slave-skip-errors | Yes | Yes | No | ||
- Variable: slave_skip_errors | Yes | Global | No | ||
slave_sql_verify_checksum | Yes | Global | Yes | ||
slave_transaction_retries | Yes | Yes | Yes | Global | Yes |
slave_type_conversions | Yes | Yes | Yes | Global | No |
slow_launch_time | Yes | Yes | Yes | Global | Yes |
slow-query-log | Yes | Yes | Yes | ||
- Variable: slow_query_log | Yes | Global | Yes | ||
slow_query_log_file | Yes | Yes | Yes | Global | Yes |
socket | Yes | Yes | Yes | Global | No |
sort_buffer_size | Yes | Yes | Yes | Both | Yes |
sql_auto_is_null | Yes | Both | Yes | ||
sql_big_selects | Yes | Both | Yes | ||
sql_buffer_result | Yes | Both | Yes | ||
sql_log_bin | Yes | Session | Yes | ||
sql_log_off | Yes | Both | Yes | ||
sql-mode | Yes | Yes | Yes | ||
- Variable: sql_mode | Yes | Both | Yes | ||
sql_notes | Yes | Both | Yes | ||
sql_quote_show_create | Yes | Both | Yes | ||
sql_require_primary_key | Yes | Yes | Yes | Both | Yes |
sql_safe_updates | Yes | Both | Yes | ||
sql_select_limit | Yes | Both | Yes | ||
sql_slave_skip_counter | Yes | Global | Yes | ||
sql_warnings | Yes | Both | Yes | ||
ssl-ca | Yes | Yes | No | ||
- Variable: ssl_ca | Yes | Global | No | ||
ssl-capath | Yes | Yes | No | ||
- Variable: ssl_capath | Yes | Global | No | ||
ssl-cert | Yes | Yes | No | ||
- Variable: ssl_cert | Yes | Global | No | ||
ssl-cipher | Yes | Yes | No | ||
- Variable: ssl_cipher | Yes | Global | No | ||
ssl-crl | Yes | Yes | No | ||
- Variable: ssl_crl | Yes | Global | No | ||
ssl-crlpath | Yes | Yes | No | ||
- Variable: ssl_crlpath | Yes | Global | No | ||
ssl_fips_mode | Yes | Yes | Yes | Global | Yes |
ssl-key | Yes | Yes | No | ||
- Variable: ssl_key | Yes | Global | No | ||
stored_program_cache | Yes | Yes | Yes | Global | Yes |
stored_program_definition_cache | Yes | Yes | Yes | Global | Yes |
super_read_only | Yes | Yes | Yes | Global | Yes |
sync_binlog | Yes | Yes | Yes | Global | Yes |
sync_master_info | Yes | Yes | Yes | Global | Yes |
sync_relay_log | Yes | Yes | Yes | Global | Yes |
sync_relay_log_info | Yes | Yes | Yes | Global | Yes |
syseventlog.facility | Yes | Yes | Yes | Global | Yes |
syseventlog.include_pid | Yes | Yes | Yes | Global | Yes |
syseventlog.tag | Yes | Yes | Yes | Global | Yes |
system_time_zone | Yes | Global | No | ||
table_definition_cache | Yes | Global | Yes | ||
table_open_cache | Yes | Global | Yes | ||
table_open_cache_instances | Yes | Global | No | ||
tablespace_definition_cache | Yes | Yes | Yes | Global | Yes |
temptable_max_ram | Yes | Yes | Yes | Global | Yes |
thread_cache_size | Yes | Yes | Yes | Global | Yes |
thread_handling | Yes | Yes | Yes | Global | No |
thread_pool_algorithm | Yes | Yes | Yes | Global | No |
thread_pool_high_priority_connection | Yes | Yes | Yes | Both | Yes |
thread_pool_max_unused_threads | Yes | Yes | Yes | Global | Yes |
thread_pool_prio_kickup_timer | Yes | Yes | Yes | Both | Yes |
thread_pool_size | Yes | Yes | Yes | Global | No |
thread_pool_stall_limit | Yes | Yes | Yes | Global | Yes |
thread_stack | Yes | Yes | Yes | Global | No |
time_format | Yes | Global | No | ||
time_zone | Yes | Both | Yes | ||
timestamp | Yes | Session | Yes | ||
tls_version | Yes | Yes | Yes | Global | No |
tmp_table_size | Yes | Yes | Yes | Both | Yes |
tmpdir | Yes | Yes | Yes | Global | No |
transaction_alloc_block_size | Yes | Yes | Yes | Both | Yes |
transaction_allow_batching | Yes | Session | Yes | ||
transaction-isolation | Yes | Yes | Yes | ||
- Variable: transaction_isolation | Yes | Both | Yes | ||
transaction_prealloc_size | Yes | Yes | Yes | Both | Yes |
transaction-read-only | Yes | Yes | Yes | ||
- Variable: transaction_read_only | Yes | Both | Yes | ||
transaction_write_set_extraction | Yes | Yes | Both | Yes | |
tx_isolation | Yes | Both | Yes | ||
tx_read_only | Yes | Both | Yes | ||
unique_checks | Yes | Both | Yes | ||
updatable_views_with_limit | Yes | Yes | Yes | Both | Yes |
use_secondary_engine | Yes | Session | Yes | ||
validate_password_check_user_name | Yes | Yes | Yes | Global | Yes |
validate_password_dictionary_file | Yes | Global | Yes | ||
validate_password_length | Yes | Global | Yes | ||
validate_password_mixed_case_count | Yes | Global | Yes | ||
validate_password_number_count | Yes | Global | Yes | ||
validate_password_policy | Yes | Global | Yes | ||
validate_password_special_char_count | Yes | Global | Yes | ||
validate_password.check_user_name | Yes | Yes | Yes | Global | Yes |
validate_password.dictionary_file | Yes | Global | Yes | ||
validate_password.length | Yes | Global | Yes | ||
validate_password.mixed_case_count | Yes | Global | Yes | ||
validate_password.number_count | Yes | Global | Yes | ||
validate_password.policy | Yes | Global | Yes | ||
validate_password.special_char_count | Yes | Global | Yes | ||
validate_user_plugins | Yes | Global | No | ||
version | Yes | Global | No | ||
version_comment | Yes | Global | No | ||
version_compile_machine | Yes | Global | No | ||
version_compile_os | Yes | Global | No | ||
version_compile_zlib | Yes | Global | No | ||
version_tokens_session | Yes | Yes | Yes | Both | Yes |
version_tokens_session_number | Yes | Yes | Yes | Both | No |
wait_timeout | Yes | Yes | Yes | Both | Yes |
warning_count | Yes | Session | No | ||
windowing_use_high_precision | Yes | Yes | Yes | Both | Yes |
Notes:
1. This option is dynamic, but only the server should set this information. You should not set the value of this variable manually.
The following table provides a list of all the status variables
applicable within mysqld
.
The table lists each variable's data type and scope. Where appropriate, a direct link to further information on the item as available.
Table 5.3 Status Variable Summary
Variable Name | Variable Type | Variable Scope |
---|---|---|
Aborted_clients |
integer | GLOBAL |
Aborted_connects |
integer | GLOBAL |
Acl_cache_items_count |
GLOBAL |
|
Audit_log_current_size |
integer | GLOBAL |
Audit_log_event_max_drop_size |
integer | GLOBAL |
Audit_log_events |
integer | GLOBAL |
Audit_log_events_filtered |
integer | GLOBAL |
Audit_log_events_lost |
integer | GLOBAL |
Audit_log_events_written |
integer | GLOBAL |
Audit_log_total_size |
integer | GLOBAL |
Audit_log_write_waits |
integer | GLOBAL |
Binlog_cache_disk_use |
integer | GLOBAL |
Binlog_cache_use |
integer | GLOBAL |
Binlog_stmt_cache_disk_use |
integer | GLOBAL |
Binlog_stmt_cache_use |
integer | GLOBAL |
Bytes_received |
integer | GLOBAL | SESSION |
Bytes_sent |
integer | GLOBAL | SESSION |
Caching_sha2_password_rsa_public_key |
GLOBAL |
|
Com_admin_commands |
integer | GLOBAL | SESSION |
Com_alter_db |
integer | GLOBAL | SESSION |
Com_alter_event |
integer | GLOBAL | SESSION |
Com_alter_function |
integer | GLOBAL | SESSION |
Com_alter_procedure |
integer | GLOBAL | SESSION |
Com_alter_resource_group |
GLOBAL |
|
Com_alter_server |
integer | GLOBAL | SESSION |
Com_alter_table |
integer | GLOBAL | SESSION |
Com_alter_tablespace |
integer | GLOBAL | SESSION |
Com_alter_user |
integer | GLOBAL | SESSION |
Com_alter_user_default_role |
GLOBAL |
|
Com_analyze |
integer | GLOBAL | SESSION |
Com_assign_to_keycache |
integer | GLOBAL | SESSION |
Com_begin |
integer | GLOBAL | SESSION |
Com_binlog |
integer | GLOBAL | SESSION |
Com_call_procedure |
integer | GLOBAL | SESSION |
Com_change_db |
integer | GLOBAL | SESSION |
Com_change_master |
integer | GLOBAL | SESSION |
Com_change_repl_filter |
integer | GLOBAL | SESSION |
Com_check |
integer | GLOBAL | SESSION |
Com_checksum |
integer | GLOBAL | SESSION |
Com_commit |
integer | GLOBAL | SESSION |
Com_create_db |
integer | GLOBAL | SESSION |
Com_create_event |
integer | GLOBAL | SESSION |
Com_create_function |
integer | GLOBAL | SESSION |
Com_create_index |
integer | GLOBAL | SESSION |
Com_create_procedure |
integer | GLOBAL | SESSION |
Com_create_resource_group |
GLOBAL |
|
Com_create_role |
GLOBAL |
|
Com_create_server |
integer | GLOBAL | SESSION |
Com_create_table |
integer | GLOBAL | SESSION |
Com_create_trigger |
integer | GLOBAL | SESSION |
Com_create_udf |
integer | GLOBAL | SESSION |
Com_create_user |
integer | GLOBAL | SESSION |
Com_create_view |
integer | GLOBAL | SESSION |
Com_dealloc_sql |
integer | GLOBAL | SESSION |
Com_delete |
integer | GLOBAL | SESSION |
Com_delete_multi |
integer | GLOBAL | SESSION |
Com_do |
integer | GLOBAL | SESSION |
Com_drop_db |
integer | GLOBAL | SESSION |
Com_drop_event |
integer | GLOBAL | SESSION |
Com_drop_function |
integer | GLOBAL | SESSION |
Com_drop_index |
integer | GLOBAL | SESSION |
Com_drop_procedure |
integer | GLOBAL | SESSION |
Com_drop_resource_group |
GLOBAL |
|
Com_drop_role |
GLOBAL |
|
Com_drop_server |
integer | GLOBAL | SESSION |
Com_drop_table |
integer | GLOBAL | SESSION |
Com_drop_trigger |
integer | GLOBAL | SESSION |
Com_drop_user |
integer | GLOBAL | SESSION |
Com_drop_view |
integer | GLOBAL | SESSION |
Com_empty_query |
integer | GLOBAL | SESSION |
Com_execute_sql |
integer | GLOBAL | SESSION |
Com_explain_other |
integer | GLOBAL | SESSION |
Com_flush |
integer | GLOBAL | SESSION |
Com_get_diagnostics |
integer | GLOBAL | SESSION |
Com_grant |
integer | GLOBAL | SESSION |
Com_grant_roles |
GLOBAL |
|
Com_group_replication_start |
GLOBAL |
|
Com_group_replication_stop |
GLOBAL |
|
Com_ha_close |
integer | GLOBAL | SESSION |
Com_ha_open |
integer | GLOBAL | SESSION |
Com_ha_read |
integer | GLOBAL | SESSION |
Com_help |
integer | GLOBAL | SESSION |
Com_insert |
integer | GLOBAL | SESSION |
Com_insert_select |
integer | GLOBAL | SESSION |
Com_install_component |
GLOBAL |
|
Com_install_plugin |
integer | GLOBAL | SESSION |
Com_kill |
integer | GLOBAL | SESSION |
Com_load |
integer | GLOBAL | SESSION |
Com_lock_tables |
integer | GLOBAL | SESSION |
Com_optimize |
integer | GLOBAL | SESSION |
Com_preload_keys |
integer | GLOBAL | SESSION |
Com_prepare_sql |
integer | GLOBAL | SESSION |
Com_purge |
integer | GLOBAL | SESSION |
Com_purge_before_date |
integer | GLOBAL | SESSION |
Com_release_savepoint |
integer | GLOBAL | SESSION |
Com_rename_table |
integer | GLOBAL | SESSION |
Com_rename_user |
integer | GLOBAL | SESSION |
Com_repair |
integer | GLOBAL | SESSION |
Com_replace |
integer | GLOBAL | SESSION |
Com_replace_select |
integer | GLOBAL | SESSION |
Com_reset |
integer | GLOBAL | SESSION |
Com_resignal |
integer | GLOBAL | SESSION |
Com_revoke |
integer | GLOBAL | SESSION |
Com_revoke_all |
integer | GLOBAL | SESSION |
Com_revoke_roles |
GLOBAL |
|
Com_rollback |
integer | GLOBAL | SESSION |
Com_rollback_to_savepoint |
integer | GLOBAL | SESSION |
Com_savepoint |
integer | GLOBAL | SESSION |
Com_select |
integer | GLOBAL | SESSION |
Com_set_option |
integer | GLOBAL | SESSION |
Com_set_resource_group |
GLOBAL |
|
Com_set_role |
GLOBAL |
|
Com_show_authors |
integer | GLOBAL | SESSION |
Com_show_binlog_events |
integer | GLOBAL | SESSION |
Com_show_binlogs |
integer | GLOBAL | SESSION |
Com_show_charsets |
integer | GLOBAL | SESSION |
Com_show_collations |
integer | GLOBAL | SESSION |
Com_show_contributors |
integer | GLOBAL | SESSION |
Com_show_create_db |
integer | GLOBAL | SESSION |
Com_show_create_event |
integer | GLOBAL | SESSION |
Com_show_create_func |
integer | GLOBAL | SESSION |
Com_show_create_proc |
integer | GLOBAL | SESSION |
Com_show_create_table |
integer | GLOBAL | SESSION |
Com_show_create_trigger |
integer | GLOBAL | SESSION |
Com_show_create_user |
integer | GLOBAL | SESSION |
Com_show_databases |
integer | GLOBAL | SESSION |
Com_show_engine_logs |
integer | GLOBAL | SESSION |
Com_show_engine_mutex |
integer | GLOBAL | SESSION |
Com_show_engine_status |
integer | GLOBAL | SESSION |
Com_show_errors |
integer | GLOBAL | SESSION |
Com_show_events |
integer | GLOBAL | SESSION |
Com_show_fields |
integer | GLOBAL | SESSION |
Com_show_function_code |
integer | GLOBAL | SESSION |
Com_show_function_status |
integer | GLOBAL | SESSION |
Com_show_grants |
integer | GLOBAL | SESSION |
Com_show_keys |
integer | GLOBAL | SESSION |
Com_show_master_status |
integer | GLOBAL | SESSION |
Com_show_ndb_status |
integer | GLOBAL | SESSION |
Com_show_new_master |
integer | GLOBAL | SESSION |
Com_show_open_tables |
integer | GLOBAL | SESSION |
Com_show_plugins |
integer | GLOBAL | SESSION |
Com_show_privileges |
integer | GLOBAL | SESSION |
Com_show_procedure_code |
integer | GLOBAL | SESSION |
Com_show_procedure_status |
integer | GLOBAL | SESSION |
Com_show_processlist |
integer | GLOBAL | SESSION |
Com_show_profile |
integer | GLOBAL | SESSION |
Com_show_profiles |
integer | GLOBAL | SESSION |
Com_show_relaylog_events |
integer | GLOBAL | SESSION |
Com_show_slave_hosts |
integer | GLOBAL | SESSION |
Com_show_slave_status |
integer | GLOBAL | SESSION |
Com_show_slave_status_nonblocking |
integer | GLOBAL | SESSION |
Com_show_status |
integer | GLOBAL | SESSION |
Com_show_storage_engines |
integer | GLOBAL | SESSION |
Com_show_table_status |
integer | GLOBAL | SESSION |
Com_show_tables |
integer | GLOBAL | SESSION |
Com_show_triggers |
integer | GLOBAL | SESSION |
Com_show_variables |
integer | GLOBAL | SESSION |
Com_show_warnings |
integer | GLOBAL | SESSION |
Com_shutdown |
integer | GLOBAL | SESSION |
Com_signal |
integer | GLOBAL | SESSION |
Com_slave_start |
integer | GLOBAL | SESSION |
Com_slave_stop |
integer | GLOBAL | SESSION |
Com_stmt_close |
integer | GLOBAL | SESSION |
Com_stmt_execute |
integer | GLOBAL | SESSION |
Com_stmt_fetch |
integer | GLOBAL | SESSION |
Com_stmt_prepare |
integer | GLOBAL | SESSION |
Com_stmt_reprepare |
integer | GLOBAL | SESSION |
Com_stmt_reset |
integer | GLOBAL | SESSION |
Com_stmt_send_long_data |
integer | GLOBAL | SESSION |
Com_truncate |
integer | GLOBAL | SESSION |
Com_uninstall_component |
GLOBAL |
|
Com_uninstall_plugin |
integer | GLOBAL | SESSION |
Com_unlock_tables |
integer | GLOBAL | SESSION |
Com_update |
integer | GLOBAL | SESSION |
Com_update_multi |
integer | GLOBAL | SESSION |
Com_xa_commit |
integer | GLOBAL | SESSION |
Com_xa_end |
integer | GLOBAL | SESSION |
Com_xa_prepare |
integer | GLOBAL | SESSION |
Com_xa_recover |
integer | GLOBAL | SESSION |
Com_xa_rollback |
integer | GLOBAL | SESSION |
Com_xa_start |
integer | GLOBAL | SESSION |
Compression |
integer | SESSION |
Connection_control_delay_generated |
GLOBAL |
|
Connection_errors_accept |
integer | GLOBAL |
Connection_errors_internal |
integer | GLOBAL |
Connection_errors_max_connections |
integer | GLOBAL |
Connection_errors_peer_address |
integer | GLOBAL |
Connection_errors_select |
integer | GLOBAL |
Connection_errors_tcpwrap |
integer | GLOBAL |
Connections |
integer | GLOBAL |
Created_tmp_disk_tables |
integer | GLOBAL | SESSION |
Created_tmp_files |
integer | GLOBAL |
Created_tmp_tables |
integer | GLOBAL | SESSION |
Delayed_errors |
integer | GLOBAL |
Delayed_insert_threads |
integer | GLOBAL |
Delayed_writes |
integer | GLOBAL |
dragnet.Status |
string | GLOBAL |
Firewall_access_denied |
integer | GLOBAL |
Firewall_access_granted |
integer | GLOBAL |
Firewall_cached_entries |
integer | GLOBAL |
Flush_commands |
integer | GLOBAL |
group_replication_primary_member |
string | GLOBAL |
Handler_commit |
integer | GLOBAL | SESSION |
Handler_delete |
integer | GLOBAL | SESSION |
Handler_external_lock |
integer | GLOBAL | SESSION |
Handler_mrr_init |
integer | GLOBAL | SESSION |
Handler_prepare |
integer | GLOBAL | SESSION |
Handler_read_first |
integer | GLOBAL | SESSION |
Handler_read_key |
integer | GLOBAL | SESSION |
Handler_read_last |
integer | GLOBAL | SESSION |
Handler_read_next |
integer | GLOBAL | SESSION |
Handler_read_prev |
integer | GLOBAL | SESSION |
Handler_read_rnd |
integer | GLOBAL | SESSION |
Handler_read_rnd_next |
integer | GLOBAL | SESSION |
Handler_rollback |
integer | GLOBAL | SESSION |
Handler_savepoint |
integer | GLOBAL | SESSION |
Handler_savepoint_rollback |
integer | GLOBAL | SESSION |
Handler_update |
integer | GLOBAL | SESSION |
Handler_write |
integer | GLOBAL | SESSION |
Innodb_available_undo_logs |
integer | GLOBAL |
Innodb_buffer_pool_bytes_data |
integer | GLOBAL |
Innodb_buffer_pool_bytes_dirty |
integer | GLOBAL |
Innodb_buffer_pool_dump_status |
string | GLOBAL |
Innodb_buffer_pool_load_status |
string | GLOBAL |
Innodb_buffer_pool_pages_data |
integer | GLOBAL |
Innodb_buffer_pool_pages_dirty |
integer | GLOBAL |
Innodb_buffer_pool_pages_flushed |
integer | GLOBAL |
Innodb_buffer_pool_pages_free |
integer | GLOBAL |
Innodb_buffer_pool_pages_latched |
integer | GLOBAL |
Innodb_buffer_pool_pages_misc |
integer | GLOBAL |
Innodb_buffer_pool_pages_total |
integer | GLOBAL |
Innodb_buffer_pool_read_ahead |
integer | GLOBAL |
Innodb_buffer_pool_read_ahead_evicted |
integer | GLOBAL |
Innodb_buffer_pool_read_ahead_rnd |
integer | GLOBAL |
Innodb_buffer_pool_read_requests |
integer | GLOBAL |
Innodb_buffer_pool_reads |
integer | GLOBAL |
Innodb_buffer_pool_resize_status |
string | GLOBAL |
Innodb_buffer_pool_wait_free |
integer | GLOBAL |
Innodb_buffer_pool_write_requests |
integer | GLOBAL |
Innodb_data_fsyncs |
integer | GLOBAL |
Innodb_data_pending_fsyncs |
integer | GLOBAL |
Innodb_data_pending_reads |
integer | GLOBAL |
Innodb_data_pending_writes |
integer | GLOBAL |
Innodb_data_read |
integer | GLOBAL |
Innodb_data_reads |
integer | GLOBAL |
Innodb_data_writes |
integer | GLOBAL |
Innodb_data_written |
integer | GLOBAL |
Innodb_dblwr_pages_written |
integer | GLOBAL |
Innodb_dblwr_writes |
integer | GLOBAL |
Innodb_have_atomic_builtins |
integer | GLOBAL |
Innodb_log_waits |
integer | GLOBAL |
Innodb_log_write_requests |
integer | GLOBAL |
Innodb_log_writes |
integer | GLOBAL |
Innodb_num_open_files |
integer | GLOBAL |
Innodb_os_log_fsyncs |
integer | GLOBAL |
Innodb_os_log_pending_fsyncs |
integer | GLOBAL |
Innodb_os_log_pending_writes |
integer | GLOBAL |
Innodb_os_log_written |
integer | GLOBAL |
Innodb_page_size |
integer | GLOBAL |
Innodb_pages_created |
integer | GLOBAL |
Innodb_pages_read |
integer | GLOBAL |
Innodb_pages_written |
integer | GLOBAL |
Innodb_row_lock_current_waits |
integer | GLOBAL |
Innodb_row_lock_time |
integer | GLOBAL |
Innodb_row_lock_time_avg |
integer | GLOBAL |
Innodb_row_lock_time_max |
integer | GLOBAL |
Innodb_row_lock_waits |
integer | GLOBAL |
Innodb_rows_deleted |
integer | GLOBAL |
Innodb_rows_inserted |
integer | GLOBAL |
Innodb_rows_read |
integer | GLOBAL |
Innodb_rows_updated |
integer | GLOBAL |
Innodb_truncated_status_writes |
integer | GLOBAL |
Key_blocks_not_flushed |
integer | GLOBAL |
Key_blocks_unused |
integer | GLOBAL |
Key_blocks_used |
integer | GLOBAL |
Key_read_requests |
integer | GLOBAL |
Key_reads |
integer | GLOBAL |
Key_write_requests |
integer | GLOBAL |
Key_writes |
integer | GLOBAL |
Last_query_cost |
numeric | SESSION |
Last_query_partial_plans |
integer | SESSION |
Locked_connects |
integer | GLOBAL |
Max_execution_time_exceeded |
integer | GLOBAL | SESSION |
Max_execution_time_set |
integer | GLOBAL | SESSION |
Max_execution_time_set_failed |
integer | GLOBAL | SESSION |
Max_used_connections |
integer | GLOBAL |
Max_used_connections_time |
datetime | GLOBAL |
mecab_charset |
string | GLOBAL |
Mysqlx_aborted_clients |
integer | GLOBAL |
Mysqlx_address |
string | GLOBAL |
Mysqlx_bytes_received |
integer | GLOBAL | SESSION |
Mysqlx_bytes_sent |
integer | GLOBAL | SESSION |
Mysqlx_connection_accept_errors |
integer | GLOBAL | SESSION |
Mysqlx_connection_errors |
integer | GLOBAL | SESSION |
Mysqlx_connections_accepted |
integer | GLOBAL |
Mysqlx_connections_closed |
integer | GLOBAL |
Mysqlx_connections_rejected |
integer | GLOBAL |
Mysqlx_crud_create_view |
integer | GLOBAL | SESSION |
Mysqlx_crud_delete |
integer | GLOBAL | SESSION |
Mysqlx_crud_drop_view |
integer | GLOBAL | SESSION |
Mysqlx_crud_find |
integer | GLOBAL | SESSION |
Mysqlx_crud_insert |
integer | GLOBAL | SESSION |
Mysqlx_crud_modify_view |
integer | GLOBAL | SESSION |
Mysqlx_crud_update |
integer | GLOBAL | SESSION |
Mysqlx_errors_sent |
integer | GLOBAL | SESSION |
Mysqlx_errors_unknown_message_type |
integer | GLOBAL | SESSION |
Mysqlx_expect_close |
integer | GLOBAL | SESSION |
Mysqlx_expect_open |
integer | GLOBAL | SESSION |
Mysqlx_init_error |
integer | GLOBAL | SESSION |
Mysqlx_notice_other_sent |
integer | GLOBAL | SESSION |
Mysqlx_notice_warning_sent |
integer | GLOBAL | SESSION |
Mysqlx_port |
string | GLOBAL |
Mysqlx_rows_sent |
integer | GLOBAL | SESSION |
Mysqlx_sessions |
integer | GLOBAL |
Mysqlx_sessions_accepted |
integer | GLOBAL |
Mysqlx_sessions_closed |
integer | GLOBAL |
Mysqlx_sessions_fatal_error |
integer | GLOBAL |
Mysqlx_sessions_killed |
integer | GLOBAL |
Mysqlx_sessions_rejected |
integer | GLOBAL |
Mysqlx_socket |
string | GLOBAL |
Mysqlx_ssl_accept_renegotiates |
integer | GLOBAL |
Mysqlx_ssl_accepts |
integer | GLOBAL |
Mysqlx_ssl_active |
integer | GLOBAL | SESSION |
Mysqlx_ssl_cipher |
integer | GLOBAL | SESSION |
Mysqlx_ssl_cipher_list |
integer | GLOBAL | SESSION |
Mysqlx_ssl_ctx_verify_depth |
integer | GLOBAL | SESSION |
Mysqlx_ssl_ctx_verify_mode |
integer | GLOBAL | SESSION |
Mysqlx_ssl_finished_accepts |
integer | GLOBAL |
Mysqlx_ssl_server_not_after |
integer | GLOBAL |
Mysqlx_ssl_server_not_before |
integer | GLOBAL |
Mysqlx_ssl_verify_depth |
integer | GLOBAL |
Mysqlx_ssl_verify_mode |
integer | GLOBAL |
Mysqlx_ssl_version |
integer | GLOBAL | SESSION |
Mysqlx_stmt_create_collection |
integer | GLOBAL | SESSION |
Mysqlx_stmt_create_collection_index |
integer | GLOBAL | SESSION |
Mysqlx_stmt_disable_notices |
integer | GLOBAL | SESSION |
Mysqlx_stmt_drop_collection |
integer | GLOBAL | SESSION |
Mysqlx_stmt_drop_collection_index |
integer | GLOBAL | SESSION |
Mysqlx_stmt_enable_notices |
integer | GLOBAL | SESSION |
Mysqlx_stmt_ensure_collection |
string | GLOBAL | SESSION |
Mysqlx_stmt_execute_mysqlx |
integer | GLOBAL | SESSION |
Mysqlx_stmt_execute_sql |
integer | GLOBAL | SESSION |
Mysqlx_stmt_execute_xplugin |
integer | GLOBAL | SESSION |
Mysqlx_stmt_kill_client |
integer | GLOBAL | SESSION |
Mysqlx_stmt_list_clients |
integer | GLOBAL | SESSION |
Mysqlx_stmt_list_notices |
integer | GLOBAL | SESSION |
Mysqlx_stmt_list_objects |
integer | GLOBAL | SESSION |
Mysqlx_stmt_ping |
integer | GLOBAL | SESSION |
Mysqlx_worker_threads |
integer | GLOBAL |
Mysqlx_worker_threads_active |
integer | GLOBAL |
Ndb_api_bytes_received_count |
integer | GLOBAL |
Ndb_api_bytes_received_count_session |
integer | SESSION |
Ndb_api_bytes_received_count_slave |
integer | GLOBAL |
Ndb_api_bytes_sent_count |
integer | GLOBAL |
Ndb_api_bytes_sent_count_slave |
integer | GLOBAL |
Ndb_api_event_bytes_count_injector |
integer | GLOBAL |
Ndb_api_event_data_count_injector |
integer | GLOBAL |
Ndb_api_event_nondata_count_injector |
integer | GLOBAL |
Ndb_api_pk_op_count |
integer | GLOBAL |
Ndb_api_pk_op_count_session |
integer | SESSION |
Ndb_api_pk_op_count_slave |
integer | GLOBAL |
Ndb_api_pruned_scan_count |
integer | GLOBAL |
Ndb_api_pruned_scan_count_session |
integer | SESSION |
Ndb_api_range_scan_count_slave |
integer | GLOBAL |
Ndb_api_read_row_count |
integer | GLOBAL |
Ndb_api_read_row_count_session |
integer | SESSION |
Ndb_api_scan_batch_count_slave |
integer | GLOBAL |
Ndb_api_table_scan_count |
integer | GLOBAL |
Ndb_api_table_scan_count_session |
integer | SESSION |
Ndb_api_trans_abort_count |
integer | GLOBAL |
Ndb_api_trans_abort_count_session |
integer | SESSION |
Ndb_api_trans_abort_count_slave |
integer | GLOBAL |
Ndb_api_trans_close_count |
integer | GLOBAL |
Ndb_api_trans_close_count_session |
integer | SESSION |
Ndb_api_trans_close_count_slave |
integer | GLOBAL |
Ndb_api_trans_commit_count |
integer | GLOBAL |
Ndb_api_trans_commit_count_session |
integer | SESSION |
Ndb_api_trans_commit_count_slave |
integer | GLOBAL |
Ndb_api_trans_local_read_row_count_slave |
integer | GLOBAL |
Ndb_api_trans_start_count |
integer | GLOBAL |
Ndb_api_trans_start_count_session |
integer | SESSION |
Ndb_api_trans_start_count_slave |
integer | GLOBAL |
Ndb_api_uk_op_count |
integer | GLOBAL |
Ndb_api_uk_op_count_slave |
integer | GLOBAL |
Ndb_api_wait_exec_complete_count |
integer | GLOBAL |
Ndb_api_wait_exec_complete_count_session |
integer | SESSION |
Ndb_api_wait_exec_complete_count_slave |
integer | GLOBAL |
Ndb_api_wait_meta_request_count |
integer | GLOBAL |
Ndb_api_wait_meta_request_count_session |
integer | SESSION |
Ndb_api_wait_nanos_count |
integer | GLOBAL |
Ndb_api_wait_nanos_count_session |
integer | SESSION |
Ndb_api_wait_nanos_count_slave |
integer | GLOBAL |
Ndb_api_wait_scan_result_count |
integer | GLOBAL |
Ndb_api_wait_scan_result_count_session |
integer | SESSION |
Ndb_api_wait_scan_result_count_slave |
integer | GLOBAL |
Ndb_cluster_node_id |
integer | GLOBAL | SESSION |
Ndb_config_from_host |
integer | GLOBAL | SESSION |
Ndb_config_from_port |
integer | GLOBAL | SESSION |
Ndb_conflict_fn_epoch_trans |
integer | GLOBAL |
Ndb_conflict_fn_max |
integer | GLOBAL |
Ndb_conflict_fn_old |
integer | GLOBAL |
Ndb_conflict_trans_detect_iter_count |
integer | GLOBAL |
Ndb_conflict_trans_row_reject_count |
integer | GLOBAL |
Ndb_last_commit_epoch_server |
integer | GLOBAL |
Ndb_last_commit_epoch_session |
integer | SESSION |
Ndb_number_of_data_nodes |
integer | GLOBAL |
Ndb_pushed_queries_defined |
integer | GLOBAL |
Ndb_pushed_queries_executed |
integer | GLOBAL |
Ndb_scan_count |
integer | GLOBAL |
Not_flushed_delayed_rows |
integer | GLOBAL |
Ongoing_anonymous_gtid_violating_transaction_count |
integer | GLOBAL |
Ongoing_anonymous_transaction_count |
integer | GLOBAL |
Ongoing_automatic_gtid_violating_transaction_count |
integer | GLOBAL |
Open_files |
integer | GLOBAL |
Open_streams |
integer | GLOBAL |
Open_table_definitions |
integer | GLOBAL |
Open_tables |
integer | GLOBAL | SESSION |
Opened_files |
integer | GLOBAL |
Opened_table_definitions |
integer | GLOBAL | SESSION |
Opened_tables |
integer | GLOBAL | SESSION |
original_commit_timestamp |
numeric | SESSION |
Performance_schema_accounts_lost |
integer | GLOBAL |
Performance_schema_cond_classes_lost |
integer | GLOBAL |
Performance_schema_cond_instances_lost |
integer | GLOBAL |
Performance_schema_digest_lost |
integer | GLOBAL |
Performance_schema_file_classes_lost |
integer | GLOBAL |
Performance_schema_file_handles_lost |
integer | GLOBAL |
Performance_schema_file_instances_lost |
integer | GLOBAL |
Performance_schema_hosts_lost |
integer | GLOBAL |
Performance_schema_index_stat_lost |
integer | GLOBAL |
Performance_schema_locker_lost |
integer | GLOBAL |
Performance_schema_memory_classes_lost |
integer | GLOBAL |
Performance_schema_metadata_lock_lost |
integer | GLOBAL |
Performance_schema_mutex_classes_lost |
integer | GLOBAL |
Performance_schema_mutex_instances_lost |
integer | GLOBAL |
Performance_schema_nested_statement_lost |
integer | GLOBAL |
Performance_schema_prepared_statements_lost |
integer | GLOBAL |
Performance_schema_program_lost |
integer | GLOBAL |
Performance_schema_rwlock_classes_lost |
integer | GLOBAL |
Performance_schema_rwlock_instances_lost |
integer | GLOBAL |
Performance_schema_session_connect_attrs_longest_seen |
GLOBAL |
|
Performance_schema_session_connect_attrs_lost |
integer | GLOBAL |
Performance_schema_socket_classes_lost |
integer | GLOBAL |
Performance_schema_socket_instances_lost |
integer | GLOBAL |
Performance_schema_stage_classes_lost |
integer | GLOBAL |
Performance_schema_statement_classes_lost |
integer | GLOBAL |
Performance_schema_table_handles_lost |
integer | GLOBAL |
Performance_schema_table_instances_lost |
integer | GLOBAL |
Performance_schema_table_lock_stat_lost |
integer | GLOBAL |
Performance_schema_thread_classes_lost |
integer | GLOBAL |
Performance_schema_thread_instances_lost |
integer | GLOBAL |
Performance_schema_users_lost |
integer | GLOBAL |
Prepared_stmt_count |
integer | GLOBAL |
Qcache_free_blocks |
integer | GLOBAL |
Qcache_free_memory |
integer | GLOBAL |
Qcache_hits |
integer | GLOBAL |
Qcache_inserts |
integer | GLOBAL |
Qcache_lowmem_prunes |
integer | GLOBAL |
Qcache_not_cached |
integer | GLOBAL |
Qcache_queries_in_cache |
integer | GLOBAL |
Qcache_total_blocks |
integer | GLOBAL |
Queries |
integer | GLOBAL | SESSION |
Questions |
integer | GLOBAL | SESSION |
Rewriter_number_loaded_rules |
integer | GLOBAL |
Rewriter_number_reloads |
integer | GLOBAL |
Rewriter_number_rewritten_queries |
integer | GLOBAL |
Rewriter_reload_error |
boolean | GLOBAL |
Rpl_semi_sync_master_clients |
integer | GLOBAL |
Rpl_semi_sync_master_net_avg_wait_time |
integer | GLOBAL |
Rpl_semi_sync_master_net_wait_time |
integer | GLOBAL |
Rpl_semi_sync_master_net_waits |
integer | GLOBAL |
Rpl_semi_sync_master_no_times |
integer | GLOBAL |
Rpl_semi_sync_master_no_tx |
integer | GLOBAL |
Rpl_semi_sync_master_status |
boolean | GLOBAL |
Rpl_semi_sync_master_timefunc_failures |
integer | GLOBAL |
Rpl_semi_sync_master_tx_avg_wait_time |
integer | GLOBAL |
Rpl_semi_sync_master_tx_wait_time |
integer | GLOBAL |
Rpl_semi_sync_master_tx_waits |
integer | GLOBAL |
Rpl_semi_sync_master_wait_pos_backtraverse |
integer | GLOBAL |
Rpl_semi_sync_master_wait_sessions |
integer | GLOBAL |
Rpl_semi_sync_master_yes_tx |
integer | GLOBAL |
Rpl_semi_sync_slave_status |
boolean | GLOBAL |
Rsa_public_key |
string | GLOBAL |
Secondary_engine_execution_count |
GLOBAL | SESSION |
|
Select_full_join |
integer | GLOBAL | SESSION |
Select_full_range_join |
integer | GLOBAL | SESSION |
Select_range |
integer | GLOBAL | SESSION |
Select_range_check |
integer | GLOBAL | SESSION |
Select_scan |
integer | GLOBAL | SESSION |
Slave_heartbeat_period |
numeric | GLOBAL |
Slave_last_heartbeat |
GLOBAL |
|
Slave_open_temp_tables |
integer | GLOBAL |
Slave_received_heartbeats |
GLOBAL |
|
Slave_retried_transactions |
integer | GLOBAL |
Slave_rows_last_search_algorithm_used |
string | GLOBAL |
Slave_running |
GLOBAL |
|
Slow_launch_threads |
integer | GLOBAL | SESSION |
Slow_queries |
integer | GLOBAL | SESSION |
Sort_merge_passes |
integer | GLOBAL | SESSION |
Sort_range |
integer | GLOBAL | SESSION |
Sort_rows |
integer | GLOBAL | SESSION |
Sort_scan |
integer | GLOBAL | SESSION |
Ssl_accept_renegotiates |
integer | GLOBAL |
Ssl_accepts |
integer | GLOBAL |
Ssl_callback_cache_hits |
integer | GLOBAL |
Ssl_cipher |
string | GLOBAL | SESSION |
Ssl_cipher_list |
string | GLOBAL | SESSION |
Ssl_client_connects |
integer | GLOBAL |
Ssl_connect_renegotiates |
integer | GLOBAL |
Ssl_ctx_verify_depth |
integer | GLOBAL |
Ssl_ctx_verify_mode |
integer | GLOBAL |
Ssl_default_timeout |
integer | GLOBAL | SESSION |
Ssl_finished_accepts |
integer | GLOBAL |
Ssl_finished_connects |
integer | GLOBAL |
Ssl_server_not_after |
integer | GLOBAL | SESSION |
Ssl_server_not_before |
integer | GLOBAL | SESSION |
Ssl_session_cache_hits |
integer | GLOBAL |
Ssl_session_cache_misses |
integer | GLOBAL |
Ssl_session_cache_mode |
string | GLOBAL |
Ssl_session_cache_overflows |
integer | GLOBAL |
Ssl_session_cache_size |
integer | GLOBAL |
Ssl_session_cache_timeouts |
integer | GLOBAL |
Ssl_sessions_reused |
integer | GLOBAL | SESSION |
Ssl_used_session_cache_entries |
integer | GLOBAL |
Ssl_verify_depth |
integer | GLOBAL | SESSION |
Ssl_verify_mode |
integer | GLOBAL | SESSION |
Ssl_version |
string | GLOBAL | SESSION |
Table_locks_immediate |
integer | GLOBAL |
Table_locks_waited |
integer | GLOBAL |
Table_open_cache_hits |
integer | GLOBAL | SESSION |
Table_open_cache_misses |
integer | GLOBAL | SESSION |
Table_open_cache_overflows |
integer | GLOBAL | SESSION |
Tc_log_max_pages_used |
integer | GLOBAL |
Tc_log_page_size |
integer | GLOBAL |
Tc_log_page_waits |
integer | GLOBAL |
Threads_cached |
integer | GLOBAL |
Threads_connected |
integer | GLOBAL |
Threads_created |
integer | GLOBAL |
Threads_running |
integer | GLOBAL |
Uptime |
integer | GLOBAL |
Uptime_since_flush_status |
integer | GLOBAL |
validate_password_dictionary_file_last_parsed |
datetime | GLOBAL |
validate_password_dictionary_file_words_count |
integer | GLOBAL |
validate_password.dictionary_file_last_parsed |
datetime | GLOBAL |
validate_password.dictionary_file_words_count |
integer | GLOBAL |
When you start the mysqld server, you can specify program options using any of the methods described in Section 4.2.3, “Specifying Program Options”. The most common methods are to provide options in an option file or on the command line. However, in most cases it is desirable to make sure that the server uses the same options each time it runs. The best way to ensure this is to list them in an option file. See Section 4.2.6, “Using Option Files”. That section also describes option file format and syntax.
mysqld reads options from the
[mysqld]
and [server]
groups. mysqld_safe reads options from the
[mysqld]
, [server]
,
[mysqld_safe]
, and
[safe_mysqld]
groups.
mysql.server reads options from the
[mysqld]
and [mysql.server]
groups.
mysqld accepts many command options. For a brief summary, execute this command:
mysqld --help
To see the full list, use this command:
mysqld --verbose --help
Some of the items in the list are actually system variables that
can be set at server startup. These can be displayed at runtime
using the SHOW VARIABLES
statement.
Some items displayed by the preceding mysqld
command do not appear in SHOW
VARIABLES
output; this is because they are options only
and not system variables.
The following list shows some of the most common server options. Additional options are described in other sections:
Options that affect security: See Section 6.1.4, “Security-Related mysqld Options and Variables”.
SSL-related options: See Section 6.4.2, “Command Options for Encrypted Connections”.
Binary log control options: See Section 5.4.4, “The Binary Log”.
Replication-related options: See Section 17.1.6, “Replication and Binary Logging Options and Variables”.
Options for loading plugins such as pluggable storage engines: See Section 5.6.1, “Installing and Uninstalling Plugins”.
Options specific to particular storage engines: See Section 15.13, “InnoDB Startup Options and System Variables” and Section 16.2.1, “MyISAM Startup Options”.
Some options control the size of buffers or caches. For a given buffer, the server might need to allocate internal data structures. These structures typically are allocated from the total memory allocated to the buffer, and the amount of space required might be platform dependent. This means that when you assign a value to an option that controls a buffer size, the amount of space actually available might differ from the value assigned. In some cases, the amount might be less than the value assigned. It is also possible that the server will adjust a value upward. For example, if you assign a value of 0 to an option for which the minimal value is 1024, the server will set the value to 1024.
Values for buffer sizes, lengths, and stack sizes are given in bytes unless otherwise specified.
Some options take file name values. Unless otherwise specified,
the default file location is the data directory if the value is a
relative path name. To specify the location explicitly, use an
absolute path name. Suppose that the data directory is
/var/mysql/data
. If a file-valued option is
given as a relative path name, it will be located under
/var/mysql/data
. If the value is an absolute
path name, its location is as given by the path name.
You can also set the values of server system variables at server
startup by using variable names as options. To assign a value to a
server system variable, use an option of the form
--
.
For example,
var_name
=value
--sort_buffer_size=384M
sets the
sort_buffer_size
variable to a
value of 384MB.
When you assign a value to a variable, MySQL might automatically correct the value to stay within a given range, or adjust the value to the closest permissible value if only certain values are permitted.
To restrict the maximum value to which a system variable can be
set at runtime with the
SET
statement, specify this maximum by using an option of the form
--maximum-
at server startup.
var_name
=value
You can change the values of most system variables at runtime with
the SET
statement. See Section 13.7.5.1, “SET Syntax for Variable Assignment”.
Section 5.1.7, “Server System Variables”, provides a full description for all variables, and additional information for setting them at server startup and runtime. For information on changing system variables, see Section 5.1.1, “Configuring the Server”.
--help
, -?
Property | Value |
---|---|
Command-Line Format | --help |
Display a short help message and exit. Use both the
--verbose
and
--help
options to see the full
message.
Property | Value |
---|---|
Command-Line Format | --allow-suspicious-udfs |
Type | boolean |
Default Value | FALSE |
This option controls whether user-defined functions that have
only an xxx
symbol for the main function
can be loaded. By default, the option is off and only UDFs
that have at least one auxiliary symbol can be loaded; this
prevents attempts at loading functions from shared object
files other than those containing legitimate UDFs. See
Section 28.4.2.6, “UDF Security Precautions”.
Property | Value |
---|---|
Command-Line Format | --ansi |
Use standard (ANSI) SQL syntax instead of MySQL syntax. For
more precise control over the server SQL mode, use the
--sql-mode
option instead. See
Section 1.8, “MySQL Standards Compliance”, and
Section 5.1.10, “Server SQL Modes”.
--basedir=
,
dir_name
-b
dir_name
Property | Value |
---|---|
Command-Line Format | --basedir=dir_name |
System Variable | basedir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
Default Value (>= 8.0.2) | parent of mysqld installation directory |
Default Value (<= 8.0.1) | configuration-dependent default |
The path to the MySQL installation directory. This option sets
the basedir
system variable.
The server executable determines its own full path name at
startup and uses the parent of the directory in which it is
located as the default
basedir
value. This in turn
enables the server to use that
basedir
when searching for
server-related information such as the
share
directory containing error
messages.
Property | Value |
---|---|
Command-Line Format | --big-tables |
System Variable | big_tables |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Enable large result sets by saving all temporary sets in files. This option prevents most “table full” errors, but also slows down queries for which in-memory tables would suffice. The server is able to handle large result sets automatically by using memory for small temporary tables and switching to disk tables where necessary.
Property | Value |
---|---|
Command-Line Format | --bind-address=addr |
System Variable | bind_address |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | string |
Default Value | * |
The MySQL server listens on one or more network sockets for
TCP/IP connections. Each socket is bound to one address, but
it is possible for an address to map onto multiple network
interfaces. To specify how the server should listen for TCP/IP
connections, use the
--bind-address
option at server
startup:
Prior to MySQL 8.0.13,
--bind-address
accepts a
single address value, which may specify a single
non-wildcard IP address or host name, or one of the
wildcard address formats that permit listening on multiple
network interfaces (*
,
0.0.0.0
, or ::
).
As of MySQL 8.0.13,
--bind-address
accepts a
single value as just described, or a list of
comma-separated values. When the option names a list of
multiple values, each value must specify a single
non-wildcard IP address or host name; none can specify a
wildcard address format (*
,
0.0.0.0
, or ::
).
IP addresses can be specified as IPv4 or IPv6 addresses. For any option value that is a host name, the server resolves the name to an IP address and binds to that address. If a host name resolves to multiple IP addresses, the server uses the first IPv4 address if there are any, or the first IPv6 address otherwise.
The server treats different types of addresses as follows:
If the address is *
, the server accepts
TCP/IP connections on all server host IPv4 interfaces,
and, if the server host supports IPv6, on all IPv6
interfaces. Use this address to permit both IPv4 and IPv6
connections on all server interfaces. This value is the
default. If the option specifies a list of multiple
values, this value is not permitted.
If the address is 0.0.0.0
, the server
accepts TCP/IP connections on all server host IPv4
interfaces. If the option specifies a list of multiple
values, this value is not permitted.
If the address is ::
, the server
accepts TCP/IP connections on all server host IPv4 and
IPv6 interfaces. If the option specifies a list of
multiple values, this value is not permitted.
If the address is an IPv4-mapped address, the server
accepts TCP/IP connections for that address, in either
IPv4 or IPv6 format. For example, if the server is bound
to ::ffff:127.0.0.1
, clients can
connect using --host=127.0.0.1
or
--host=::ffff:127.0.0.1
.
If the address is a “regular” IPv4 or IPv6
address (such as 127.0.0.1
or
::1
), the server accepts TCP/IP
connections only for that IPv4 or IPv6 address.
If binding to any address fails, the server produces an error and does not start.
Examples:
--bind-address=*
The server listens on all IPv4 or IPv6 addresses, as
specified by the *
wildcard.
--bind-address=198.51.100.20
The server listens only on the
198.51.100.20
IPv4 address.
--bind-address=198.51.100.20,2001:db8:0:f101::1
The server listens on the 198.51.100.20
IPv4 address and the 2001:db8:0:f101::1
IPv6 address.
--bind-address=198.51.100.20,*
This produces an error because wildcard addresses are not
permitted when
--bind-address
names a list
of multiple values.
When --bind-address
names a
single value (wildcard or non-wildcard), the server listens on
a single socket, which for a wildcard address may be bound to
multiple network interfaces. When
--bind-address
names a list of
multiple values, the server listens on one socket per value,
with each socket bound to a single network interface. The
number of sockets is linear with the number of values
specified. Depending on operating system connection-acceptance
efficiency, long value lists might incur a performance penalty
for accepting TCP/IP connections.
If you intend to bind the server to a specific address, be
sure that the mysql.user
grant table
contains an account with administrative privileges that you
can use to connect to that address. Otherwise, you will not be
able to shut down the server. For example, if you bind the
server to *
, you can connect to it using
all existing accounts. But if you bind the server to
::1
, it accepts connections only on that
address. In that case, first make sure that the
'root'@'::1'
account is present in the
mysql.user
table so you can still connect
to the server to shut it down.
--binlog-format={ROW|STATEMENT|MIXED}
Property | Value |
---|---|
Command-Line Format | --binlog-format=format |
System Variable | binlog_format |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | ROW |
Valid Values |
|
Specify whether to use row-based, statement-based, or mixed replication. Statement-based is the default in MySQL 8.0. See Section 17.2.1, “Replication Formats”.
Under some conditions, changing this variable at runtime is not possible, or causes replication to fail. See Section 5.4.4.2, “Setting The Binary Log Format”, for more information.
Setting the binary logging format without enabling binary
logging sets the
binlog_format
global system
variable and logs a warning.
Property | Value |
---|---|
Command-Line Format | --character-sets-dir=dir_name |
System Variable | character_sets_dir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The directory where character sets are installed. See Section 10.14, “Character Set Configuration”.
--character-set-client-handshake
Property | Value |
---|---|
Command-Line Format | --character-set-client-handshake |
Type | boolean |
Default Value | TRUE |
Do not ignore character set information sent by the client. To
ignore client information and use the default server character
set, use
--skip-character-set-client-handshake
;
this makes MySQL behave like MySQL 4.0.
--character-set-filesystem=
charset_name
Property | Value |
---|---|
Command-Line Format | --character-set-filesystem=name |
System Variable | character_set_filesystem |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value | binary |
The file system character set. This option sets the
character_set_filesystem
system variable.
--character-set-server=
,
charset_name
-C
charset_name
Property | Value |
---|---|
Command-Line Format | --character-set-server |
System Variable | character_set_server |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | latin1 |
Use charset_name
as the default
server character set. See
Section 10.14, “Character Set Configuration”. If you use this
option to specify a nondefault character set, you should also
use --collation-server
to
specify the collation.
--chroot=
,
dir_name
-r
dir_name
Property | Value |
---|---|
Command-Line Format | --chroot=dir_name |
Type | directory name |
Put the mysqld server in a closed
environment during startup by using the
chroot()
system call. This is a recommended
security measure. Use of this option somewhat limits
LOAD DATA
INFILE
and
SELECT ... INTO
OUTFILE
.
--collation-server=
collation_name
Property | Value |
---|---|
Command-Line Format | --collation-server |
System Variable | collation_server |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4_0900_ai_ci |
Default Value (8.0.0) | latin1_swedish_ci |
Use collation_name
as the default
server collation. See Section 10.14, “Character Set Configuration”.
Property | Value |
---|---|
Command-Line Format | --console |
Platform Specific | Windows |
(Windows only.) Cause the default error log destination to be the console. This affects log writers that base their own output destination on the default destination. See Section 5.4.2, “The Error Log”. mysqld does not close the console window if this option is used.
--console
takes precedence over
--log-error
if both are given.
Property | Value |
---|---|
Command-Line Format | --core-file |
Type | boolean |
Default Value | OFF |
Write a core file if mysqld dies. The name
and location of the core file is system dependent. On Linux, a
core file named
core.
is
written to the current working directory of the process, which
for mysqld is the data directory.
pid
pid
represents the process ID of
the server process. On macOS, a core file named
core.
is
written to the pid
/cores
directory. On
Solaris, use the coreadm command to specify
where to write the core file and how to name it.
For some systems, to get a core file you must also specify the
--core-file-size
option to
mysqld_safe. See
Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”. On some systems, such as
Solaris, you do not get a core file if you are also using the
--user
option. There might be
additional restrictions or limitations. For example, it might
be necessary to execute ulimit -c unlimited
before starting the server. Consult your system documentation.
--daemonize
,
-D
Property | Value |
---|---|
Command-Line Format | --daemonize[={OFF|ON}] |
Type | boolean |
Default Value | OFF |
This option causes the server to run as a traditional, forking daemon, permitting it to work with operating systems that use systemd for process control. For more information, see Section 2.5.9, “Managing MySQL Server with systemd”.
--daemonize
is mutually
exclusive with --initialize
and
--initialize-insecure
.
If the server is started using the
--daemonize
option and is not connected to a
tty device, a default error logging option of
--log-error=""
is used in the absence of an
explicit logging option, to direct error output to the default
log file.
-D
is a synonym for
--daemonize
.
--datadir=
,
dir_name
-h
dir_name
Property | Value |
---|---|
Command-Line Format | --datadir=dir_name |
System Variable | datadir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The path to the MySQL server data directory. This option sets
the datadir
system variable.
See the description of that variable.
--debug[=
,
debug_options
]-# [
debug_options
]
Property | Value |
---|---|
Command-Line Format | --debug[=debug_options] |
System Variable | debug |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (Windows) | d:t:i:O,\mysqld.trace |
Default Value (Unix) | d:t:i:o,/tmp/mysqld.trace |
If MySQL is configured with the
-DWITH_DEBUG=1
CMake option, you can use this option to
get a trace file of what mysqld is doing. A
typical debug_options
string is
d:t:o,
.
The default is file_name
d:t:i:o,/tmp/mysqld.trace
on
Unix and d:t:i:O,\mysqld.trace
on Windows.
Using -DWITH_DEBUG=1
to
configure MySQL with debugging support enables you to use the
--debug="d,parser_debug"
option
when you start the server. This causes the Bison parser that
is used to process SQL statements to dump a parser trace to
the server's standard error output. Typically, this output is
written to the error log.
This option may be given multiple times. Values that begin
with +
or -
are added to
or subtracted from the previous value. For example,
--debug=T
--debug=+P
sets the value to
P:T
.
For more information, see Section 28.5.3, “The DBUG Package”.
Property | Value |
---|---|
Command-Line Format | --debug-sync-timeout[=#] |
Type | integer |
Controls whether the Debug Sync facility for testing and
debugging is enabled. Use of Debug Sync requires that MySQL be
configured with the
-DENABLE_DEBUG_SYNC=1
CMake option (see
Section 2.8.4, “MySQL Source-Configuration Options”). If Debug Sync
is not compiled in, this option is not available. The option
value is a timeout in seconds. The default value is 0, which
disables Debug Sync. To enable it, specify a value greater
than 0; this value also becomes the default timeout for
individual synchronization points. If the option is given
without a value, the timeout is set to 300 seconds.
For a description of the Debug Sync facility and how to use synchronization points, see MySQL Internals: Test Synchronization.
Property | Value |
---|---|
Command-Line Format | --default-storage-engine=name |
System Variable | default_storage_engine |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | InnoDB |
Set the default storage engine for tables. See
Chapter 16, Alternative Storage Engines. This option sets the
storage engine for permanent tables only. To set the storage
engine for TEMPORARY
tables, set the
default_tmp_storage_engine
system variable.
If you disable the default storage engine at server startup,
you must set the default engine for both permanent and
TEMPORARY
tables to a different engine or
the server will not start.
Property | Value |
---|---|
Command-Line Format | --default-time-zone=name |
Type | string |
Set the default server time zone. This option sets the global
time_zone
system variable. If
this option is not given, the default time zone is the same as
the system time zone (given by the value of the
system_time_zone
system
variable.
--defaults-extra-file=
file_name
Read this option file after the global option file but (on
Unix) before the user option file. If the file does not exist
or is otherwise inaccessible, an error occurs.
file_name
is interpreted relative
to the current directory if given as a relative path name
rather than a full path name. This must be the first option on
the command line if it is used.
For additional information about this option, see Section 4.2.7, “Command-Line Options that Affect Option-File Handling”.
Read only the given option file. If the file does not exist or
is otherwise inaccessible, an error occurs.
file_name
is interpreted relative
to the current directory if given as a relative path name
rather than a full path name.
Exception: Even with
--defaults-file
,
mysqld reads
mysqld-auto.cnf
.
This must be the first option on the command line if it is
used, except that if the server is started with the
--defaults-file
and
--install
(or
--install-manual
) options,
--install
(or
--install-manual
) must be
first.
For additional information about this option, see Section 4.2.7, “Command-Line Options that Affect Option-File Handling”.
Read not only the usual option groups, but also groups with
the usual names and a suffix of
str
. For example,
mysqld normally reads the
[mysqld]
group. If the
--defaults-group-suffix=_other
option is given, mysqld also reads the
[mysqld_other]
group.
For additional information about this option, see Section 4.2.7, “Command-Line Options that Affect Option-File Handling”.
--delay-key-write[={OFF|ON|ALL}]
Property | Value |
---|---|
Command-Line Format | --delay-key-write[=name] |
System Variable | delay_key_write |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | ON |
Valid Values |
|
Specify how to use delayed key writes. Delayed key writing
causes key buffers not to be flushed between writes for
MyISAM
tables. OFF
disables delayed key writes. ON
enables
delayed key writes for those tables that were created with the
DELAY_KEY_WRITE
option.
ALL
delays key writes for all
MyISAM
tables. See
Section 5.1.1, “Configuring the Server”, and
Section 16.2.1, “MyISAM Startup Options”.
If you set this variable to ALL
, you
should not use MyISAM
tables from within
another program (such as another MySQL server or
myisamchk) when the tables are in use.
Doing so leads to index corruption.
Property | Value |
---|---|
Command-Line Format | --des-key-file=file_name |
Deprecated | Yes (removed in 8.0.3) |
This option was removed in MySQL 8.0.3.
--early-plugin-load=
plugin_list
Property | Value |
---|---|
Command-Line Format | --early-plugin-load=plugin_list |
Type | string |
Default Value | empty string |
This option tells the server which plugins to load before
loading mandatory built-in plugins and before storage engine
initialization. If multiple
--early-plugin-load
options are
given, only the last one is used.
The option value is a semicolon-separated list of
name
=
plugin_library
and plugin_library
values. Each
name
is the name of a plugin to
load, and plugin_library
is the
name of the library file that contains the plugin code. If a
plugin library is named without any preceding plugin name, the
server loads all plugins in the library. The server looks for
plugin library files in the directory named by the
plugin_dir
system variable.
For example, if plugins named myplug1
and
myplug2
have library files
myplug1.so
and
myplug2.so
, use this option to perform an
early plugin load:
shell> mysqld --early-plugin-load="myplug1=myplug1.so;myplug2=myplug2.so"
Quotes are used around the argument value because otherwise a
semicolon (;
) is interpreted as a special
character by some command interpreters. (Unix shells treat it
as a command terminator, for example.)
Each named plugin is loaded early for a single invocation of
mysqld only. After a restart, the plugin is
not loaded early unless
--early-plugin-load
is used
again.
If the server is started using
--initialize
or
--initialize-insecure
, plugins
specified by
--early-plugin-load
are not
loaded.
If the server is run with
--help
, plugins specified by
--early-plugin-load
are loaded
but not initialized. This behavior ensures that plugin options
are displayed in the help message.
The default --early-plugin-load
value is empty. To load the keyring_file
plugin, you must use an explicit
--early-plugin-load
option with
a nonempty value.
The InnoDB
tablespace encryption feature
relies on the keyring_file
plugin for
encryption key management, and the
keyring_file
plugin must be loaded prior to
storage engine initialization to facilitate
InnoDB
recovery for encrypted tables.
Administrators who want the keyring_file
plugin loaded at startup should use the appropriate nonempty
option value; for example, keyring_file.so
on Unix and Unix-like systems and
keyring_file.dll
on Windows.
For information about InnoDB
tablespace
encryption, see
Section 15.7.11, “InnoDB Tablespace Encryption”. For general
information about plugin loading, see
Section 5.6.1, “Installing and Uninstalling Plugins”.
Property | Value |
---|---|
Command-Line Format | --enable-named-pipe |
Platform Specific | Windows |
Enable support for named pipes. This option applies only on Windows.
Property | Value |
---|---|
Command-Line Format | --event-scheduler[=value] |
System Variable | event_scheduler |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value (>= 8.0.3) | ON |
Default Value (<= 8.0.2) | OFF |
Valid Values |
|
Enable or disable, and start or stop, the event scheduler.
For detailed information, see
The
--event-scheduler
Option.
--exit-info[=
,
flags
]-T [
flags
]
Property | Value |
---|---|
Command-Line Format | --exit-info[=flags] |
Type | integer |
This is a bitmask of different flags that you can use for debugging the mysqld server. Do not use this option unless you know exactly what it does!
Property | Value |
---|---|
Command-Line Format | --external-locking |
Type | boolean |
Default Value | FALSE |
Enable external locking (system locking), which is disabled by
default. If you use this option on a system on which
lockd
does not fully work (such as Linux),
it is easy for mysqld to deadlock.
To disable external locking explicitly, use
--skip-external-locking
.
External locking affects only
MyISAM
table access. For more
information, including conditions under which it can and
cannot be used, see Section 8.11.5, “External Locking”.
Property | Value |
---|---|
Command-Line Format | --flush |
System Variable | flush |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Flush (synchronize) all changes to disk after each SQL statement. Normally, MySQL does a write of all changes to disk only after each SQL statement and lets the operating system handle the synchronizing to disk. See Section B.5.3.3, “What to Do If MySQL Keeps Crashing”.
If --flush
is specified, the
value of flush_time
does
not matter and changes to
flush_time
have no effect
on flush behavior.
Property | Value |
---|---|
Command-Line Format | --gdb |
Type | boolean |
Default Value | FALSE |
Install an interrupt handler for SIGINT
(needed to stop mysqld with
^C
to set breakpoints) and disable stack
tracing and core file handling. See Section 28.5, “Debugging and Porting MySQL”.
On Windows, this option also suppresses the forking that is
used to implement the RESTART
statement: Forking enables one process to act as a monitor to
the other, which acts as the server. However, forking makes
determining the server process to attach to for debugging more
difficult, so starting the server with
--gdb
suppresses forking. For a
server started with this option,
RESTART
simply exits and does
not restart.
In non-debug settings,
--no-monitor
may be used to
suppress forking the monitor process.
Property | Value |
---|---|
Command-Line Format | --general-log |
System Variable | general_log |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Specify the initial general query log state. With no argument
or an argument of 1, the
--general-log
option enables
the log. If omitted or given with an argument of 0, the option
disables the log.
--initialize
,
-I
Property | Value |
---|---|
Command-Line Format | --initialize |
Type | boolean |
Default Value | OFF |
This option is used to initialize a MySQL installation by
creating the data directory and populating the tables in the
mysql
system database. For more
information, see
Section 2.9.1.1, “Initializing the Data Directory Manually Using mysqld”.
When the server is started with
--initialize
, some
functionality is unavailable that limits the statements
permitted in any file named by the
--init-file
option. For more information, see
the description of that option. In addition, the
disabled_storage_engines
system variable has no effect.
--initialize
is mutually
exclusive with --daemonize
.
-I
is a synonym for
--initialize
.
Property | Value |
---|---|
Command-Line Format | --initialize-insecure |
Type | boolean |
Default Value | OFF |
This option is used to initialize a MySQL installation by
creating the data directory and populating the tables in the
mysql
system database. This option implies
--initialize
. For more
information, see the description of that option, and
Section 2.9.1.1, “Initializing the Data Directory Manually Using mysqld”.
--initialize-insecure
is
mutually exclusive with
--daemonize
.
Property | Value |
---|---|
Command-Line Format | --init-file=file_name |
System Variable | init_file |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | file name |
Read SQL statements from this file at startup. Each statement must be on a single line and should not include comments.
If the server is started with the
--initialize
or
--initialize-insecure
option,
it operates in bootstap mode and some functionality is
unavailable that limits the statements permitted in the file.
These include statements that relate to account management
(such as CREATE USER
or
GRANT
), replication, and global
transaction identifiers. See
Section 17.1.3, “Replication with Global Transaction Identifiers”.
--innodb-
xxx
Set an option for the InnoDB
storage
engine. The InnoDB
options are listed in
Section 15.13, “InnoDB Startup Options and System Variables”.
Property | Value |
---|---|
Command-Line Format | --install [service_name] |
Platform Specific | Windows |
(Windows only) Install the server as a Windows service that
starts automatically during Windows startup. The default
service name is MySQL
if no
service_name
value is given. For
more information, see Section 2.3.5.8, “Starting MySQL as a Windows Service”.
If the server is started with the
--defaults-file
and
--install
options,
--install
must be first.
--install-manual
[
service_name
]
Property | Value |
---|---|
Command-Line Format | --install-manual [service_name] |
Platform Specific | Windows |
(Windows only) Install the server as a Windows service that
must be started manually. It does not start automatically
during Windows startup. The default service name is
MySQL
if no
service_name
value is given. For
more information, see Section 2.3.5.8, “Starting MySQL as a Windows Service”.
If the server is started with the
--defaults-file
and
--install-manual
options,
--install-manual
must be
first.
--language=
lang_name
,
-L lang_name
Property | Value |
---|---|
Command-Line Format | --language=name |
Deprecated | Yes; use lc-messages-dir |
System Variable | language |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
Default Value | /usr/local/mysql/share/mysql/english/ |
The language to use for error messages.
lang_name
can be given as the
language name or as the full path name to the directory where
the language files are installed. See
Section 10.11, “Setting the Error Message Language”.
--lc-messages-dir
and
--lc-messages
should be used
rather than --language
, which
is deprecated (and handled as an alias for
--lc-messages-dir
). The
--language
option will be
removed in a future MySQL release.
Property | Value |
---|---|
Command-Line Format | --large-pages |
System Variable | large_pages |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Platform Specific | Linux |
Type | boolean |
Default Value | FALSE |
Some hardware/operating system architectures support memory pages greater than the default (usually 4KB). The actual implementation of this support depends on the underlying hardware and operating system. Applications that perform a lot of memory accesses may obtain performance improvements by using large pages due to reduced Translation Lookaside Buffer (TLB) misses.
MySQL supports the Linux implementation of large page support
(which is called HugeTLB in Linux). See
Section 8.12.3.2, “Enabling Large Page Support”. For Solaris support of
large pages, see the description of the
--super-large-pages
option.
--large-pages
is disabled by
default.
Property | Value |
---|---|
Command-Line Format | --lc-messages=name |
System Variable | lc_messages |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value | en_US |
The locale to use for error messages. The default is
en_US
. The server converts the argument to
a language name and combines it with the value of
--lc-messages-dir
to produce
the location for the error message file. See
Section 10.11, “Setting the Error Message Language”.
Property | Value |
---|---|
Command-Line Format | --lc-messages-dir=dir_name |
System Variable | lc_messages_dir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The directory where error messages are located. The server
uses the value together with the value of
--lc-messages
to produce the
location for the error message file. See
Section 10.11, “Setting the Error Message Language”.
Property | Value |
---|---|
Command-Line Format | --local-service |
(Windows only) A --local-service
option
following the service name causes the server to run using the
LocalService
Windows account that has
limited system privileges. If both
--defaults-file
and
--local-service
are given following the
service name, they can be in any order. See
Section 2.3.5.8, “Starting MySQL as a Windows Service”.
Property | Value |
---|---|
Command-Line Format | --log-error[=file_name] |
System Variable | log_error |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | file name |
Set the default error log destination to the named file. This affects log writers that base their own output destination on the default destination. See Section 5.4.2, “The Error Log”.
If the option names no file, the default error log destination
on Unix and Unix-like systems is a file named
in the data directory. The default destination on Windows is
the same, unless the host_name
.err--pid-file
option is specified. In that case, the file name is the PID
file base name with a suffix of .err
in
the data directory.
If the option names a file, the default destination is that
file (with an .err
suffix added if the
name has no suffix), located under the data directory unless
an absolute path name is given to specify a different
location.
If error log output cannot be redirected to the error log file, an error occurs and startup fails.
On Windows, --console
takes
precedence over --log-error
if
both are given. In this case, the default error log
destination is the console rather than a file.
Property | Value |
---|---|
Command-Line Format | --log-isam[=file_name] |
Type | file name |
Log all MyISAM
changes to this file (used
only when debugging MyISAM
).
Property | Value |
---|---|
Command-Line Format | --log-output=name |
System Variable | log_output |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | set |
Default Value | FILE |
Valid Values |
|
This option determines the destination for general query log
and slow query log output. The option value can be given as
one or more of the words TABLE
,
FILE
, or NONE
.
TABLE
select logging to the
general_log
and
slow_log
tables in the
mysql
database as a destination.
FILE
selects logging to log files as a
destination. NONE
disables logging. If
NONE
is present in the option value, it
takes precedence over any other words that are present.
TABLE
and FILE
can both
be given to select to both log output destinations.
This option selects log output destinations, but does not
enable log output. To do that, use the
--general_log
and
--slow_query_log
options. For
FILE
logging, the
--general_log_file
and
-slow_query_log_file
options determine the
log file location. For more information, see
Section 5.4.1, “Selecting General Query and Slow Query Log Output Destinations”.
--log-queries-not-using-indexes
Property | Value |
---|---|
Command-Line Format | --log-queries-not-using-indexes |
System Variable | log_queries_not_using_indexes |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
If you are using this option with the slow query log enabled, queries that are expected to retrieve all rows are logged. See Section 5.4.5, “The Slow Query Log”. This option does not necessarily mean that no index is used. For example, a query that uses a full index scan uses an index but would be logged because the index would not limit the number of rows.
Property | Value |
---|---|
Command-Line Format | --log-raw[=value] |
Type | boolean |
Default Value | OFF |
Passwords in certain statements written to the general query
log, slow query log, and binary log are rewritten by the
server not to occur literally in plain text. Password
rewriting can be suppressed for the general query log by
starting the server with the
--log-raw
option. This option
may be useful for diagnostic purposes, to see the exact text
of statements as received by the server, but for security
reasons is not recommended for production use.
If a query rewrite plugin is installed, the
--log-raw
option affects
statement logging as follows:
For more information, see Section 6.1.2.3, “Passwords and Logging”.
Property | Value |
---|---|
Command-Line Format | --log-short-format |
Type | boolean |
Default Value | FALSE |
Log less information to the slow query log, if it has been activated.
Property | Value |
---|---|
Command-Line Format | --log-tc=file_name |
Type | file name |
Default Value | tc.log |
The name of the memory-mapped transaction coordinator log file
(for XA transactions that affect multiple storage engines when
the binary log is disabled). The default name is
tc.log
. The file is created under the
data directory if not given as a full path name. This option
is unused.
Property | Value |
---|---|
Command-Line Format | --log-tc-size=# |
Type | integer |
Default Value | 6 * page size |
Minimum Value | 6 * page size |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
The size in bytes of the memory-mapped transaction coordinator log. The default and minimum values are 6 times the page size, and the value must be a multiple of the page size.
--log-warnings[=
,
level
]-W [
level
]
Property | Value |
---|---|
Command-Line Format | --log-warnings[=#] |
Deprecated | Yes (removed in 8.0.3) |
System Variable | log_warnings |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 2 |
Minimum Value | 0 |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
This option was removed in MySQL 8.0.3. Use the
log_error_verbosity
system
variable instead.
Property | Value |
---|---|
Command-Line Format | --low-priority-updates |
System Variable | low_priority_updates |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | FALSE |
Give table-modifying operations
(INSERT
,
REPLACE
,
DELETE
,
UPDATE
) lower priority than
selects. This can also be done using {INSERT |
REPLACE | DELETE | UPDATE} LOW_PRIORITY ...
to lower
the priority of only one query, or by SET
LOW_PRIORITY_UPDATES=1
to change the priority in one
thread. This affects only storage engines that use only
table-level locking (MyISAM
,
MEMORY
, MERGE
). See
Section 8.11.2, “Table Locking Issues”.
--min-examined-row-limit=
number
Property | Value |
---|---|
Command-Line Format | --min-examined-row-limit=# |
System Variable | min_examined_row_limit |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 0 |
Minimum Value | 0 |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
When this option is set, queries which examine fewer than
number
rows are not written to the
slow query log. The default is 0.
Property | Value |
---|---|
Command-Line Format | --memlock |
Type | boolean |
Default Value | FALSE |
Lock the mysqld process in memory. This option might help if you have a problem where the operating system is causing mysqld to swap to disk.
--memlock
works on systems that
support the mlockall()
system call; this
includes Solaris, most Linux distributions that use a 2.4 or
higher kernel, and perhaps other Unix systems. On Linux
systems, you can tell whether or not
mlockall()
(and thus this option) is
supported by checking to see whether or not it is defined in
the system mman.h
file, like this:
shell> grep mlockall /usr/include/sys/mman.h
If mlockall()
is supported, you should see
in the output of the previous command something like the
following:
extern int mlockall (int __flags) __THROW;
Use of this option may require you to run the server as
root
, which, for reasons of security, is
normally not a good idea. See
Section 6.1.5, “How to Run MySQL as a Normal User”.
On Linux and perhaps other systems, you can avoid the need
to run the server as root
by changing the
limits.conf
file. See the notes
regarding the memlock limit in
Section 8.12.3.2, “Enabling Large Page Support”.
You must not try to use this option on a system that does
not support the mlockall()
system call;
if you do so, mysqld will very likely
crash as soon as you try to start it.
Property | Value |
---|---|
Command-Line Format | --myisam-block-size=# |
Type | integer |
Default Value | 1024 |
Minimum Value | 1024 |
Maximum Value | 16384 |
The block size to be used for MyISAM
index
pages.
--myisam-recover-options[=
option
[,option
]...]]
Property | Value |
---|---|
Command-Line Format | --myisam-recover-options[=name] |
Type | enumeration |
Default Value | OFF |
Valid Values |
|
Set the MyISAM
storage engine recovery
mode. The option value is any combination of the values of
OFF
, DEFAULT
,
BACKUP
, FORCE
, or
QUICK
. If you specify multiple values,
separate them by commas. Specifying the option with no
argument is the same as specifying DEFAULT
,
and specifying with an explicit value of ""
disables recovery (same as a value of OFF
).
If recovery is enabled, each time mysqld
opens a MyISAM
table, it checks whether the
table is marked as crashed or was not closed properly. (The
last option works only if you are running with external
locking disabled.) If this is the case,
mysqld runs a check on the table. If the
table was corrupted, mysqld attempts to
repair it.
The following options affect how the repair works.
Option | Description |
---|---|
OFF |
No recovery. |
DEFAULT |
Recovery without backup, forcing, or quick checking. |
BACKUP |
If the data file was changed during recovery, save a backup of the
file as
. |
FORCE |
Run recovery even if we would lose more than one row from the
.MYD file. |
QUICK |
Do not check the rows in the table if there are not any delete blocks. |
Before the server automatically repairs a table, it writes a
note about the repair to the error log. If you want to be able
to recover from most problems without user intervention, you
should use the options BACKUP,FORCE
. This
forces a repair of a table even if some rows would be deleted,
but it keeps the old data file as a backup so that you can
later examine what happened.
Do not read any option files. If program startup fails due to
reading unknown options from an option file,
--no-defaults
can be used to
prevent them from being read. This must be the first option on
the command line if it is used.
For additional information about this option, see Section 4.2.7, “Command-Line Options that Affect Option-File Handling”.
Property | Value |
---|---|
Command-Line Format | --no-dd-upgrade |
Introduced | 8.0.4 |
Type | boolean |
Default Value | FALSE |
Prevents the automatic upgrade of data dictionary tables when starting the MySQL server. This option would typically be used when starting the MySQL server following an in-place upgrade of the MySQL server to a new version, which may include changes to data dictionary table definitions.
When --no-dd-upgrade
is
specified, and the server finds that the data dictionary
version of the server is different from the version stored in
the data dictionary, startup fails with an error stating that
data dictionary upgrade is prohibited.
During a normal startup, the data dictionary version of the server is compared to the version stored in the data dictionary to determine if data dictionary table definitions should be upgraded. If an upgrade is necessary and supported, the server creates data dictionary tables with updated definitions, copies persisted metadata to the new tables, atomically replaces the old tables with the new ones, and reinitializes the data dictionary. If an upgrade is not necessary, startup continues without updating data dictionary tables.
Property | Value |
---|---|
Command-Line Format | --no-monitor |
Introduced | 8.0.12 |
Platform Specific | Windows |
Type | boolean |
Default Value | FALSE |
(Windows only). This option suppresses the forking that is
used to implement the RESTART
statement: Forking enables one process to act as a monitor to
the other, which acts as the server. For a server started with
this option, RESTART
simply
exits and does not restart.
--no-monitor
is not available
prior to MySQL 8.0.12. The
--gdb
option can be used as a
workaround.
Property | Value |
---|---|
Command-Line Format | --old-alter-table |
System Variable | old_alter_table |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
When this option is given, the server does not use the
optimized method of processing an ALTER
TABLE
operation. It reverts to using a temporary
table, copying over the data, and then renaming the temporary
table to the original, as used by MySQL 5.0 and earlier. For
more information on the operation of
ALTER TABLE
, see
Section 13.1.8, “ALTER TABLE Syntax”.
Property | Value |
---|---|
Command-Line Format | --old-style-user-limits |
Type | boolean |
Default Value | FALSE |
Enable old-style user limits. (Before MySQL 5.0.3, account
resource limits were counted separately for each host from
which a user connected rather than per account row in the
user
table.) See
Section 6.3.6, “Setting Account Resource Limits”.
Property | Value |
---|---|
Command-Line Format | --open-files-limit=# |
System Variable | open_files_limit |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 5000, with possible adjustment |
Minimum Value | 0 |
Maximum Value | platform dependent |
Changes the number of file descriptors available to
mysqld. You should try increasing the value
of this option if mysqld gives you the
error Too many open files
.
mysqld uses the option value to reserve
descriptors with setrlimit()
. Internally,
the maximum value for this option is the maximum unsigned
integer value, but the actual maximum is platform dependent.
If the requested number of file descriptors cannot be
allocated, mysqld writes a warning to the
error log.
mysqld may attempt to allocate more than
the requested number of descriptors (if they are available),
using the values of
max_connections
and
table_open_cache
to estimate
whether more descriptors will be needed.
On Unix, the value cannot be set greater than ulimit -n.
--performance-schema-xxx
Configure a Performance Schema option. For details, see Section 25.13, “Performance Schema Command Options”.
Property | Value |
---|---|
Command-Line Format | --pid-file=file_name |
System Variable | pid_file |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | file name |
The path name of the process ID file. The server creates the
file in the data directory unless an absolute path name is
given to specify a different directory. If you specify this
option, you must specify a value. If you do not specify this
option, MySQL uses a default value of
,
where host_name
.pidhost_name
is the name of the
host machine.
The process ID file is used by other programs such as mysqld_safe to determine the server's process ID. On Windows, this variable also affects the default error log file name. See Section 5.4.2, “The Error Log”.
Specifies an option that pertains to a server plugin. For
example, many storage engines can be built as plugins, and for
such engines, options for them can be specified with a
--plugin
prefix. Thus, the
--innodb_file_per_table
option
for InnoDB
can be specified as
--plugin-innodb_file_per_table
.
For boolean options that can be enabled or disabled, the
--skip
prefix and other alternative formats
are supported as well (see
Section 4.2.5, “Program Option Modifiers”). For example,
--skip-plugin-innodb_file_per_table
disables innodb_file_per_table
.
The rationale for the --plugin
prefix is that
it enables plugin options to be specified unambiguously if
there is a name conflict with a built-in server option. For
example, were a plugin writer to name a plugin
“sql” and implement a “mode” option,
the option name might be
--sql-mode
, which would
conflict with the built-in option of the same name. In such
cases, references to the conflicting name are resolved in
favor of the built-in option. To avoid the ambiguity, users
can specify the plugin option as
--plugin-sql-mode
. Use of the
--plugin
prefix for plugin options is
recommended to avoid any question of ambiguity.
Property | Value |
---|---|
Command-Line Format | --plugin-load=plugin_list |
Type | string |
This option tells the server to load the named plugins at
startup. If multiple
--plugin-load
options are
given, only the last one is used. Additional plugins to load
may be specified using
--plugin-load-add
options.
The option value is a semicolon-separated list of
name
=
plugin_library
and plugin_library
values. Each
name
is the name of a plugin to
load, and plugin_library
is the
name of the library file that contains the plugin code. If a
plugin library is named without any preceding plugin name, the
server loads all plugins in the library. The server looks for
plugin library files in the directory named by the
plugin_dir
system variable.
For example, if plugins named myplug1
and
myplug2
have library files
myplug1.so
and
myplug2.so
, use this option to perform an
early plugin load:
shell> mysqld --plugin-load="myplug1=myplug1.so;myplug2=myplug2.so"
Quotes are used around the argument value here because
otherwise semicolon (;
) is interpreted as a
special character by some command interpreters. (Unix shells
treat it as a command terminator, for example.)
Each named plugin is loaded for a single invocation of
mysqld only. After a restart, the plugin is
not loaded unless --plugin-load
is used again. This is in contrast to
INSTALL PLUGIN
, which adds an
entry to the mysql.plugins
table to cause
the plugin to be loaded for every normal server startup.
Under normal startup, the server determines which plugins to
load by reading the mysql.plugins
system
table. If the server is started with the
--skip-grant-tables
option, it
does not consult the mysql.plugins
table
and does not load plugins listed there.
--plugin-load
enables plugins
to be loaded even when
--skip-grant-tables
is given.
--plugin-load
also enables
plugins to be loaded at startup that cannot be loaded at
runtime.
For additional information about plugin loading, see Section 5.6.1, “Installing and Uninstalling Plugins”.
Property | Value |
---|---|
Command-Line Format | --plugin-load-add=plugin_list |
Type | string |
This option complements the
--plugin-load
option.
--plugin-load-add
adds a plugin
or plugins to the set of plugins to be loaded at startup. The
argument format is the same as for
--plugin-load
.
--plugin-load-add
can be used
to avoid specifying a large set of plugins as a single long
unwieldy --plugin-load
argument.
--plugin-load-add
can be given
in the absence of
--plugin-load
, but any instance
of --plugin-load-add
that
appears before --plugin-load
.
has no effect because
--plugin-load
resets the set of
plugins to load. In other words, these options:
--plugin-load=x --plugin-load-add=y
are equivalent to this option:
--plugin-load="x;y"
But these options:
--plugin-load-add=y --plugin-load=x
are equivalent to this option:
--plugin-load=x
For additional information about plugin loading, see Section 5.6.1, “Installing and Uninstalling Plugins”.
--port=
,
port_num
-P
port_num
Property | Value |
---|---|
Command-Line Format | --port=# |
System Variable | port |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 3306 |
Minimum Value | 0 |
Maximum Value | 65535 |
The port number to use when listening for TCP/IP connections.
On Unix and Unix-like systems, the port number must be 1024 or
higher unless the server is started by the
root
system user.
Property | Value |
---|---|
Command-Line Format | --port-open-timeout=# |
Type | integer |
Default Value | 0 |
On some systems, when the server is stopped, the TCP/IP port might not become available immediately. If the server is restarted quickly afterward, its attempt to reopen the port can fail. This option indicates how many seconds the server should wait for the TCP/IP port to become free if it cannot be opened. The default is not to wait.
Print the program name and all options that it gets from
option files. Password values are masked. This must be the
first option on the command line if it is used, except that it
may be used immediately after
--defaults-file
or
--defaults-extra-file
.
For additional information about this option, see Section 4.2.7, “Command-Line Options that Affect Option-File Handling”.
Property | Value |
---|---|
Command-Line Format | --remove [service_name] |
Platform Specific | Windows |
(Windows only) Remove a MySQL Windows service. The default
service name is MySQL
if no
service_name
value is given. For
more information, see Section 2.3.5.8, “Starting MySQL as a Windows Service”.
Property | Value |
---|---|
Command-Line Format | --safe-user-create |
Type | boolean |
Default Value | FALSE |
If this option is enabled, a user cannot create new MySQL
users by using the GRANT
statement unless the user has the
INSERT
privilege for the
mysql.user
table or any column in the
table. If you want a user to have the ability to create new
users that have those privileges that the user has the right
to grant, you should grant the user the following privilege:
GRANT INSERT(user) ON mysql.user TO 'user_name
'@'host_name
';
This ensures that the user cannot change any privilege columns
directly, but has to use the
GRANT
statement to give
privileges to other users.
Property | Value |
---|---|
Command-Line Format | --secure-auth |
Deprecated | Yes (removed in 8.0.3) |
System Variable | secure_auth |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | ON |
Valid Values | ON |
This option was removed in MySQL 8.0.3.
Property | Value |
---|---|
Command-Line Format | --secure-file-priv=dir_name |
System Variable | secure_file_priv |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | string |
Default Value | platform specific |
Valid Values |
|
This option sets the
secure_file_priv
system
variable, which is used to limit the effect of data import and
export operations, such as those performed by the
LOAD DATA
and
SELECT ... INTO
OUTFILE
statements and the
LOAD_FILE()
function. For more
information, see the description of
secure_file_priv
.
Property | Value |
---|---|
Command-Line Format | --shared-memory[={0,1}] |
System Variable | shared_memory |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Platform Specific | Windows |
Type | boolean |
Default Value | FALSE |
Enable shared-memory connections by local clients. This option is available only on Windows.
--shared-memory-base-name=
name
Property | Value |
---|---|
Command-Line Format | --shared-memory-base-name=name |
System Variable | shared_memory_base_name |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Platform Specific | Windows |
Type | string |
Default Value | MYSQL |
The name of shared memory to use for shared-memory
connections. This option is available only on Windows. The
default name is MYSQL
. The name is case
sensitive.
Turn off the ability to select and insert at the same time on
MyISAM
tables. (This is to be used only if
you think you have found a bug in this feature.) See
Section 8.11.3, “Concurrent Inserts”.
Property | Value |
---|---|
Command-Line Format |
|
Turns the Event Scheduler OFF
. This is not
the same as disabling the Event Scheduler, which requires
setting
--event-scheduler=DISABLED
; see
The
--event-scheduler
Option, for more
information.
Property | Value |
---|---|
Command-Line Format | --skip-grant-tables |
Type | boolean |
Default Value | FALSE |
This option causes the server to start without using the
privilege system at all, which gives anyone with access to the
server unrestricted access to all
databases. You can cause a running server to start
using the grant tables again by executing mysqladmin
flush-privileges or mysqladmin
reload command from a system shell, or by issuing a
MySQL FLUSH PRIVILEGES
statement after connecting to the server.
If the server is started with the
--skip-grant-tables
option to
disable authentication checks, the server enables
--skip-networking
automatically
to prevent remote connections.
This option also causes the server to suppress during its
startup sequence the loading of user-defined functions (UDFs),
scheduled events, and plugins that were installed with the
INSTALL PLUGIN
statement. To
cause plugins to be loaded anyway, use the
--plugin-load
option.
--skip-grant-tables
also causes
the disabled_storage_engines
system variable to have no effect.
This option does not cause loading of server components to be suppressed during server startup.
FLUSH PRIVILEGES
might be
executed implicitly by other actions performed after startup.
For example, mysql_upgrade flushes the
privileges during the upgrade procedure.
Property | Value |
---|---|
Command-Line Format | --skip-host-cache |
Disable use of the internal host cache for faster name-to-IP resolution. In this case, the server performs a DNS lookup every time a client connects. See Section 8.12.4.2, “DNS Lookup Optimization and the Host Cache”.
Use of --skip-host-cache
is
similar to setting the
host_cache_size
system
variable to 0, but
host_cache_size
is more
flexible because it can also be used to resize, enable, or
disable the host cache at runtime, not just at server startup.
If you start the server with
--skip-host-cache
, that does
not prevent changes to the value of
host_cache_size
, but such
changes have no effect and the cache is not re-enabled even if
host_cache_size
is set larger
than 0.
Disable the InnoDB
storage engine. In this
case, because the default storage engine is
InnoDB
, the server will not start
unless you also use
--default-storage-engine
and
--default-tmp-storage-engine
to
set the default to some other engine for both permanent and
TEMPORARY
tables.
The InnoDB
storage engine cannot be
disabled, and the
--skip-innodb
option is deprecated and has no effect. Its use results in a
warning. This option will be removed in a future MySQL
release.
Property | Value |
---|---|
Command-Line Format | --skip-name-resolve |
System Variable | skip_name_resolve |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Do not resolve host names when checking client connections.
Use only IP addresses. If you use this option, all
Host
column values in the grant tables must
be IP addresses. See Section 8.12.4.2, “DNS Lookup Optimization and the Host Cache”.
Depending on the network configuration of your system and the
Host
values for your accounts, clients may
need to connect using an explicit --host
option, such as --host=127.0.0.1
or
--host=::1
.
An attempt to connect to the host 127.0.0.1
normally resolves to the localhost
account.
However, this fails if the server is run with the
--skip-name-resolve
option. If
you plan to do that, make sure that an account exists that can
accept a connection. For example, to be able to connect as
root
using
--host=127.0.0.1
or
--host=::1
, create these accounts:
CREATE USER 'root'@'127.0.0.1' IDENTIFIED BY 'root-password
'; CREATE USER 'root'@'::1' IDENTIFIED BY 'root-password
';
Property | Value |
---|---|
Command-Line Format | --skip-networking |
System Variable | skip_networking |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Do not listen for TCP/IP connections at all. All interaction with mysqld must be made using named pipes or shared memory (on Windows) or Unix socket files (on Unix). This option is highly recommended for systems where only local clients are permitted. See Section 8.12.4.2, “DNS Lookup Optimization and the Host Cache”.
If the server is started with the
--skip-grant-tables
option to
disable authentication checks, the server enables
--skip-networking
to prevent
remote connections.
Options that begin with --ssl
specify whether to permit clients to connect using SSL and
indicate where to find SSL keys and certificates. See
Section 6.4.2, “Command Options for Encrypted Connections”.
Property | Value |
---|---|
Command-Line Format | --standalone |
Platform Specific | Windows |
Available on Windows only; instructs the MySQL server not to run as a service.
Property | Value |
---|---|
Command-Line Format | --super-large-pages |
Platform Specific | Solaris |
Type | boolean |
Default Value | FALSE |
Standard use of large pages in MySQL attempts to use the
largest size supported, up to 4MB. Under Solaris, a
“super large pages” feature enables uses of pages
up to 256MB. This feature is available for recent SPARC
platforms. It can be enabled or disabled by using the
--super-large-pages
or
--skip-super-large-pages
option.
--symbolic-links
,
--skip-symbolic-links
Property | Value |
---|---|
Command-Line Format | --symbolic-links |
Deprecated | 8.0.2 |
Type | boolean |
Default Value (>= 8.0.2) | OFF |
Default Value (<= 8.0.1) | ON |
Enable or disable symbolic link support. On Unix, enabling
symbolic links means that you can link a
MyISAM
index file or data file to another
directory with the INDEX DIRECTORY
or
DATA DIRECTORY
option of the
CREATE TABLE
statement. If you
delete or rename the table, the files that its symbolic links
point to also are deleted or renamed. See
Section 8.12.2.2, “Using Symbolic Links for MyISAM Tables on Unix”.
Symbolic link support, along with the the
--symbolic-links
option that
controls it, is deprecated and will be removed in a future
version of MySQL. In addition, the option is disabled by
default. The related
have_symlink
system
variable also is deprecated and will be removed in a future
version of MySQL.
This option has no meaning on Windows.
Property | Value |
---|---|
Command-Line Format | --skip-show-database |
System Variable | skip_show_database |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
This option sets the
skip_show_database
system
variable that controls who is permitted to use the
SHOW DATABASES
statement. See
Section 5.1.7, “Server System Variables”.
Property | Value |
---|---|
Command-Line Format | --skip-stack-trace |
Do not write stack traces. This option is useful when you are running mysqld under a debugger. On some systems, you also must use this option to get a core file. See Section 28.5, “Debugging and Porting MySQL”.
Property | Value |
---|---|
Command-Line Format | --slow-query-log |
System Variable | slow_query_log |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Specify the initial slow query log state. With no argument or
an argument of 1, the
--slow-query-log
option enables
the log. If omitted or given with an argument of 0, the option
disables the log.
Property | Value |
---|---|
Command-Line Format | --slow-start-timeout=# |
Type | integer |
Default Value | 15000 |
This option controls the Windows service control manager's service start timeout. The value is the maximum number of milliseconds that the service control manager waits before trying to kill the windows service during startup. The default value is 15000 (15 seconds). If the MySQL service takes too long to start, you may need to increase this value. A value of 0 means there is no timeout.
Property | Value |
---|---|
Command-Line Format | --socket={file_name|pipe_name} |
System Variable | socket |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | string |
Default Value (Other) | /tmp/mysql.sock |
Default Value (Windows) | MySQL |
On Unix, this option specifies the Unix socket file to use
when listening for local connections. The default value is
/tmp/mysql.sock
. If this option is given,
the server creates the file in the data directory unless an
absolute path name is given to specify a different directory.
On Windows, the option specifies the pipe name to use when
listening for local connections that use a named pipe. The
default value is MySQL
(not case
sensitive).
--sql-mode=
value
[,value
[,value
...]]
Property | Value |
---|---|
Command-Line Format | --sql-mode=name |
System Variable | sql_mode |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | Yes |
Type | set |
Default Value (>= 8.0.11) | ONLY_FULL_GROUP_BY STRICT_TRANS_TABLES NO_ZERO_IN_DATE NO_ZERO_DATE ERROR_FOR_DIVISION_BY_ZERO NO_ENGINE_SUBSTITUTION |
Default Value (<= 8.0.4) | ONLY_FULL_GROUP_BY STRICT_TRANS_TABLES NO_ZERO_IN_DATE NO_ZERO_DATE ERROR_FOR_DIVISION_BY_ZERO NO_AUTO_CREATE_USER NO_ENGINE_SUBSTITUTION |
Valid Values (>= 8.0.11) |
|
Valid Values (>= 8.0.1, <= 8.0.4) |
|
Valid Values (8.0.0) |
|
Set the SQL mode. See Section 5.1.10, “Server SQL Modes”.
MySQL installation programs may configure the SQL mode during the installation process.
If the SQL mode differs from the default or from what you expect, check for a setting in an option file that the server reads at startup.
Property | Value |
---|---|
Command-Line Format | --sysdate-is-now |
Type | boolean |
Default Value | FALSE |
SYSDATE()
by default returns
the time at which it executes, not the time at which the
statement in which it occurs begins executing. This differs
from the behavior of NOW()
.
This option causes SYSDATE()
to
be an alias for NOW()
. For
information about the implications for binary logging and
replication, see the description for
SYSDATE()
in
Section 12.7, “Date and Time Functions” and for SET
TIMESTAMP
in
Section 5.1.7, “Server System Variables”.
--tc-heuristic-recover={COMMIT|ROLLBACK}
Property | Value |
---|---|
Command-Line Format | --tc-heuristic-recover=name |
Type | enumeration |
Default Value | COMMIT |
Valid Values |
|
The type of decision to use in the heuristic recovery process. To use this option, two or more storage engines that support XA transactions must be installed.
Property | Value |
---|---|
Command-Line Format | --temp-pool |
Deprecated | Yes (removed in 8.0.1) |
Type | boolean |
Default Value (Other) | FALSE |
Default Value (Linux) | TRUE |
This option is obsolete and was removed in MySQL 8.0.1.
Property | Value |
---|---|
Command-Line Format | --transaction-isolation=name |
System Variable | transaction_isolation |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | REPEATABLE-READ |
Valid Values |
|
Sets the default transaction isolation level. The
level
value can be
READ-UNCOMMITTED
,
READ-COMMITTED
,
REPEATABLE-READ
, or
SERIALIZABLE
. See
Section 13.3.7, “SET TRANSACTION Syntax”.
The default transaction isolation level can also be set at
runtime using the SET
TRANSACTION
statement or by setting the
transaction_isolation
system
variable.
Property | Value |
---|---|
Command-Line Format | --transaction-read-only |
System Variable | transaction_read_only |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Sets the default transaction access mode. By default, read-only mode is disabled, so the mode is read/write.
To set the default transaction access mode at runtime, use the
SET TRANSACTION
statement or
set the transaction_read_only
system variable. See Section 13.3.7, “SET TRANSACTION Syntax”.
--tmpdir=
,
dir_name
-t
dir_name
Property | Value |
---|---|
Command-Line Format | --tmpdir=dir_name |
System Variable | tmpdir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The path of the directory to use for creating temporary files.
It might be useful if your default /tmp
directory resides on a partition that is too small to hold
temporary tables. This option accepts several paths that are
used in round-robin fashion. Paths should be separated by
colon characters (:
) on Unix and semicolon
characters (;
) on Windows. If the MySQL
server is acting as a replication slave, you should not set
--tmpdir
to point to a
directory on a memory-based file system or to a directory that
is cleared when the server host restarts. For more information
about the storage location of temporary files, see
Section B.5.3.5, “Where MySQL Stores Temporary Files”. A replication slave needs
some of its temporary files to survive a machine restart so
that it can replicate temporary tables or
LOAD DATA
INFILE
operations. If files in the temporary file
directory are lost when the server restarts, replication
fails.
--user={
,
user_name
|user_id
}-u
{
user_name
|user_id
}
Property | Value |
---|---|
Command-Line Format | --user=name |
Type | string |
Run the mysqld server as the user having
the name user_name
or the numeric
user ID user_id
.
(“User” in this context refers to a system login
account, not a MySQL user listed in the grant tables.)
This option is mandatory when starting
mysqld as root
. The
server changes its user ID during its startup sequence,
causing it to run as that particular user rather than as
root
. See
Section 6.1.1, “Security Guidelines”.
To avoid a possible security hole where a user adds a
--user=root
option to a
my.cnf
file (thus causing the server to
run as root
), mysqld
uses only the first --user
option specified and produces a warning if there are multiple
--user
options. Options in
/etc/my.cnf
and
$MYSQL_HOME/my.cnf
are processed before
command-line options, so it is recommended that you put a
--user
option in
/etc/my.cnf
and specify a value other
than root
. The option in
/etc/my.cnf
is found before any other
--user
options, which ensures
that the server runs as a user other than
root
, and that a warning results if any
other --user
option is found.
Use this option with the --help
option for detailed help.
--version
, -V
Display version information and exit.
The MySQL server maintains many system variables that indicate how
it is configured. Each system variable has a default value. System
variables can be set at server startup using options on the
command line or in an option file. Most of them can be changed
dynamically at runtime using the
SET
statement, which enables you to modify operation of the server
without having to stop and restart it. You can also use system
variable values in expressions.
At runtime, setting the global value of a system variable normally
requires the SYSTEM_VARIABLES_ADMIN
or SUPER
privilege, with exceptions
as noted in individual variable descriptions. For some system
variables, setting the session value also requires the sme
privilege; again, with exceptions as noted in individual variable
descriptions.
There are several ways to see the names and values of system variables:
To see the values that a server will use based on its compiled-in defaults and any option files that it reads, use this command:
mysqld --verbose --help
To see the values that a server will use based on its compiled-in defaults, ignoring the settings in any option files, use this command:
mysqld --no-defaults --verbose --help
To see the current values used by a running server, use the
SHOW VARIABLES
statement or the
Performance Schema system variable tables. See
Section 25.11.13, “Performance Schema System Variable Tables”.
This section provides a description of each system variable. For a system variable summary table, see Section 5.1.4, “Server System Variable Reference”. For more information about manipulation of system variables, see Section 5.1.8, “Using System Variables”.
For additional system variable information, see these sections:
Section 5.1.8, “Using System Variables”, discusses the syntax for setting and displaying system variable values.
Section 5.1.8.3, “Dynamic System Variables”, lists the variables that can be set at runtime.
Information on tuning system variables can be found in Section 5.1.1, “Configuring the Server”.
Section 15.13, “InnoDB Startup Options and System Variables”, lists
InnoDB
system variables.
For information on server system variables specific to replication, see Section 17.1.6, “Replication and Binary Logging Options and Variables”.
Some of the following variable descriptions refer to
“enabling” or “disabling” a variable.
These variables can be enabled with the
SET
statement by setting them to ON
or
1
, or disabled by setting them to
OFF
or 0
. Boolean
variables can be set at startup to the values
ON
, TRUE
,
OFF
, and FALSE
(not case
sensitive), as well as 1
and
0
. See Section 4.2.5, “Program Option Modifiers”.
Some system variables control the size of buffers or caches. For a given buffer, the server might need to allocate internal data structures. These structures typically are allocated from the total memory allocated to the buffer, and the amount of space required might be platform dependent. This means that when you assign a value to a system variable that controls a buffer size, the amount of space actually available might differ from the value assigned. In some cases, the amount might be less than the value assigned. It is also possible that the server will adjust a value upward. For example, if you assign a value of 0 to a variable for which the minimal value is 1024, the server will set the value to 1024.
Values for buffer sizes, lengths, and stack sizes are given in bytes unless otherwise specified.
Some system variables take file name values. Unless otherwise
specified, the default file location is the data directory if the
value is a relative path name. To specify the location explicitly,
use an absolute path name. Suppose that the data directory is
/var/mysql/data
. If a file-valued variable is
given as a relative path name, it will be located under
/var/mysql/data
. If the value is an absolute
path name, its location is as given by the path name.
Property | Value |
---|---|
Command-Line Format | --activate-all-roles-on-login |
Introduced | 8.0.2 |
System Variable | activate_all_roles_on_login |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Whether to enable automatic activation of all granted roles when users log in to the server:
If
activate_all_roles_on_login
is enabled, the server activates all roles granted to each
account at login time. This takes precedence over default
roles specified with SET DEFAULT
ROLE
.
If
activate_all_roles_on_login
is disabled, the server activates the default roles
specified with SET DEFAULT
ROLE
, if any, at login time.
Granted roles include those granted explicitly to the user and
those named in the
mandatory_roles
system
variable value.
activate_all_roles_on_login
applies only at login time, and at the beginning of execution
for stored programs and views that execute in definer context.
To change the active roles within a session, use
SET ROLE
. To change the active
roles for a stored program, the program body should execute
SET ROLE
.
authentication_windows_log_level
Property | Value |
---|---|
Command-Line Format | --authentication-windows-log-level |
Introduced | 8.0.11 |
Type | integer |
Default Value | 0 |
Minimum Value | 0 |
Maximum Value | 4 |
This variable is available only if the
authentication_windows
Windows
authentication plugin is enabled and debugging code is
enabled. See
Section 6.5.1.6, “Windows Pluggable Authentication”.
This variable sets the logging level for the Windows authentication plugin. The following table shows the permitted values.
Value | Description |
---|---|
0 | No logging |
1 | Log only error messages |
2 | Log level 1 messages and warning messages |
3 | Log level 2 messages and information notes |
4 | Log level 3 messages and debug messages |
authentication_windows_use_principal_name
Property | Value |
---|---|
Command-Line Format | --authentication-windows-use-principal-name |
Introduced | 8.0.11 |
Type | boolean |
Default Value | ON |
This variable is available only if the
authentication_windows
Windows
authentication plugin is enabled. See
Section 6.5.1.6, “Windows Pluggable Authentication”.
A client that authenticates using the
InitSecurityContext()
function should
provide a string identifying the service to which it connects
(targetName
). MySQL uses the
principal name (UPN) of the account under which the server is
running. The UPN has the form
and need not be registered anywhere to be used. This UPN is
sent by the server at the beginning of authentication
handshake.
user_id
@computer_name
This variable controls whether the server sends the UPN in the
initial challenge. By default, the variable is enabled. For
security reasons, it can be disabled to avoid sending the
server's account name to a client in clear text. If the
variable is disabled, the server always sends a
0x00
byte in the first challenge, the
client does not specify targetName
,
and as a result, NTLM authentication is used.
If the server fails to obtain its UPN (which will happen primarily in environments that do not support Kerberos authentication), the UPN is not sent by the server and NTLM authentication is used.
Property | Value |
---|---|
Command-Line Format | --autocommit[=#] |
System Variable | autocommit |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | ON |
The autocommit mode. If set to 1, all changes to a table take
effect immediately. If set to 0, you must use
COMMIT
to accept a transaction
or ROLLBACK
to cancel it. If autocommit
is 0 and you change it to 1, MySQL performs an automatic
COMMIT
of any open transaction.
Another way to begin a transaction is to use a
START
TRANSACTION
or
BEGIN
statement. See Section 13.3.1, “START TRANSACTION, COMMIT, and ROLLBACK Syntax”.
By default, client connections begin with
autocommit
set to 1. To cause
clients to begin with a default of 0, set the global
autocommit
value by starting
the server with the
--autocommit=0
option. To set
the variable using an option file, include these lines:
[mysqld] autocommit=0
Property | Value |
---|---|
System Variable | automatic_sp_privileges |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | TRUE |
When this variable has a value of 1 (the default), the server
automatically grants the
EXECUTE
and
ALTER ROUTINE
privileges to the
creator of a stored routine, if the user cannot already
execute and alter or drop the routine. (The
ALTER ROUTINE
privilege is
required to drop the routine.) The server also automatically
drops those privileges from the creator when the routine is
dropped. If
automatic_sp_privileges
is 0,
the server does not automatically add or drop these
privileges.
The creator of a routine is the account used to execute the
CREATE
statement for it. This might not be
the same as the account named as the
DEFINER
in the routine definition.
See also Section 23.2.2, “Stored Routines and MySQL Privileges”.
Property | Value |
---|---|
Command-Line Format | --auto-generate-certs[={OFF|ON}] |
System Variable | auto_generate_certs |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | ON |
This variable is available if the server was compiled using OpenSSL (see Section 6.4.4, “OpenSSL Versus wolfSSL”). It controls whether the server autogenerates SSL key and certificate files in the data directory, if they do not already exist.
At startup, the server automatically generates server-side and
client-side SSL certificate and key files in the data
directory if the
auto_generate_certs
system
variable is enabled, no SSL options other than
--ssl
are specified, and the
server-side SSL files are missing from the data directory.
These files enable secure client connections using SSL; see
Section 6.4.1, “Configuring MySQL to Use Encrypted Connections”.
For more information about SSL file autogeneration, including file names and characteristics, see Section 6.4.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”
The
sha256_password_auto_generate_rsa_keys
and
caching_sha2_password_auto_generate_rsa_keys
system variables are related but control autogeneration of RSA
key-pair files needed for secure password exchange using RSA
over unencypted connections.
Property | Value |
---|---|
Command-Line Format | --avoid-temporal-upgrade={OFF|ON} |
Deprecated | Yes |
System Variable | avoid_temporal_upgrade |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
This variable controls whether ALTER
TABLE
implicitly upgrades temporal columns found to
be in pre-5.6.4 format (TIME
,
DATETIME
, and
TIMESTAMP
columns without
support for fractional seconds precision). Upgrading such
columns requires a table rebuild, which prevents any use of
fast alterations that might otherwise apply to the operation
to be performed.
This variable is disabled by default. Enabling it causes
ALTER TABLE
not to rebuild
temporal columns and thereby be able to take advantage of
possible fast alterations.
This variable is deprecated and will be removed in a future MySQL release.
Property | Value |
---|---|
System Variable | back_log |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | -1 (signifies autosizing; do not assign this literal value) |
Minimum Value | 1 |
Maximum Value | 65535 |
The number of outstanding connection requests MySQL can have.
This comes into play when the main MySQL thread gets very many
connection requests in a very short time. It then takes some
time (although very little) for the main thread to check the
connection and start a new thread. The
back_log
value indicates how
many requests can be stacked during this short time before
MySQL momentarily stops answering new requests. You need to
increase this only if you expect a large number of connections
in a short period of time.
In other words, this value is the size of the listen queue for
incoming TCP/IP connections. Your operating system has its own
limit on the size of this queue. The manual page for the Unix
listen()
system call should have more
details. Check your OS documentation for the maximum value for
this variable. back_log
cannot be set higher than your operating system limit.
The default value is the value of
max_connections
, which
enables the permitted backlog to adjust to the maximum
permitted number of connections.
Property | Value |
---|---|
Command-Line Format | --basedir=dir_name |
System Variable | basedir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
Default Value (>= 8.0.2) | parent of mysqld installation directory |
Default Value (<= 8.0.1) | configuration-dependent default |
The path to the MySQL installation base directory.
Property | Value |
---|---|
Command-Line Format | --big-tables |
System Variable | big_tables |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
If set to 1, all temporary tables are stored on disk rather
than in memory. This is a little slower, but the error
The table
does not occur for
tbl_name
is
fullSELECT
operations that require
a large temporary table. The default value for a new
connection is 0 (use in-memory temporary tables). Normally,
you should never need to set this variable. When in-memory
internal temporary tables are managed by
the TempTable
storage engine (the default),
and the maximum amount of memory that can be occupied by the
TempTable
storage engine is exceeded, the
TempTable
storage engine starts storing
data to temporary files on disk. When in-memory temporary
tables are managed by the MEMORY
storage
engine, in-memory tables are automatically converted to
disk-based tables as required. For more information, see
Section 8.4.4, “Internal Temporary Table Use in MySQL”.
Property | Value |
---|---|
Command-Line Format | --bind-address=addr |
System Variable | bind_address |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | string |
Default Value | * |
The value of the --bind-address
option.
Property | Value |
---|---|
Command-Line Format | --block-encryption-mode=# |
System Variable | block_encryption_mode |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value | aes-128-ecb |
This variable controls the block encryption mode for
block-based algorithms such as AES. It affects encryption for
AES_ENCRYPT()
and
AES_DECRYPT()
.
block_encryption_mode
takes a
value in
aes-
format, where keylen
-mode
keylen
is the key
length in bits and mode
is the
encryption mode. The value is not case-sensitive. Permitted
keylen
values are 128, 192, and
256. Permitted encryption modes depend on whether MySQL was
compiled using OpenSSL or wolfSSL:
For OpenSSL, permitted mode
values are: ECB
,
CBC
, CFB1
,
CFB8
, CFB128
,
OFB
For wolfSSL, permitted mode
values are: ECB
, CBC
For example, this statement causes the AES encryption functions to use a key length of 256 bits and the CBC mode:
SET block_encryption_mode = 'aes-256-cbc';
An error occurs for attempts to set
block_encryption_mode
to a
value containing an unsupported key length or a mode that the
SSL library does not support.
Property | Value |
---|---|
Command-Line Format | --bulk-insert-buffer-size=# |
System Variable | bulk_insert_buffer_size |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | Yes |
Type | integer |
Default Value | 8388608 |
Minimum Value | 0 |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
MyISAM
uses a special tree-like cache to
make bulk inserts faster for
INSERT ...
SELECT
, INSERT ... VALUES (...), (...),
...
, and
LOAD DATA
INFILE
when adding data to nonempty tables. This
variable limits the size of the cache tree in bytes per
thread. Setting it to 0 disables this optimization. The
default value is 8MB.
caching_sha2_password_auto_generate_rsa_keys
Property | Value |
---|---|
Command-Line Format | --caching-sha2-password-auto-generate-rsa-keys[={OFF|ON}] |
Introduced | 8.0.4 |
System Variable | caching_sha2_password_auto_generate_rsa_keys |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | ON |
This variable is available if the server was compiled using OpenSSL (see Section 6.4.4, “OpenSSL Versus wolfSSL”). The server uses it to determine whether to autogenerate RSA private/public key-pair files in the data directory if they do not already exist.
At startup, the server automatically generates RSA
private/public key-pair files in the data directory if all of
these conditions are true: The
sha256_password_auto_generate_rsa_keys
or
caching_sha2_password_auto_generate_rsa_keys
system variable is enabled; no RSA options are specified; the
RSA files are missing from the data directory. These key-pair
files enable secure password exchange using RSA over
unencrypted connections for accounts authenticated by the
sha256_password
or
caching_sha2_password
plugin; see
Section 6.5.1.2, “SHA-256 Pluggable Authentication”, and
Section 6.5.1.3, “Caching SHA-2 Pluggable Authentication”.
For more information about RSA file autogeneration, including file names and characteristics, see Section 6.4.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”
The auto_generate_certs
system variable is related but controls autogeneration of SSL
certificate and key files needed for secure connections using
SSL.
caching_sha2_password_private_key_path
Property | Value |
---|---|
Command-Line Format | --caching-sha2-password-private-key-path=file_name |
Introduced | 8.0.3 |
System Variable | caching_sha2_password_private_key_path |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | file name |
Default Value | private_key.pem |
This variable specifies the path name of the RSA private key
file for the caching_sha2_password
authentication plugin. If the file is named as a relative
path, it is interpreted relative to the server data directory.
The file must be in PEM format.
Because this file stores a private key, its access mode should be restricted so that only the MySQL server can read it.
For information about
caching_sha2_password
, see
Section 6.5.1.3, “Caching SHA-2 Pluggable Authentication”.
caching_sha2_password_public_key_path
Property | Value |
---|---|
Command-Line Format | --caching-sha2-password-public-key-path=file_name |
Introduced | 8.0.3 |
System Variable | caching_sha2_password_public_key_path |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | file name |
Default Value | public_key.pem |
This variable specifies the path name of the RSA public key
file for the caching_sha2_password
authentication plugin. If the file is named as a relative
path, it is interpreted relative to the server data directory.
The file must be in PEM format.
For information about
caching_sha2_password
, including
information about how clients request the RSA public key, see
Section 6.5.1.3, “Caching SHA-2 Pluggable Authentication”.
Property | Value |
---|---|
System Variable | character_set_client |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | utf8 |
The character set for statements that arrive from the client.
The session value of this variable is set using the character
set requested by the client when the client connects to the
server. (Many clients support a
--default-character-set
option to enable this
character set to be specified explicitly. See also
Section 10.4, “Connection Character Sets and Collations”.) The global value of the
variable is used to set the session value in cases when the
client-requested value is unknown or not available, or the
server is configured to ignore client requests:
The client is from a version of MySQL older than MySQL 4.1, and thus does not request a character set.
The client requests a character set not known to the
server. For example, a Japanese-enabled client requests
sjis
when connecting to a server not
configured with sjis
support.
mysqld was started with the
--skip-character-set-client-handshake
option, which causes it to ignore client character set
configuration. This reproduces MySQL 4.0 behavior and is
useful should you wish to upgrade the server without
upgrading all the clients.
ucs2
, utf16
,
utf16le
, and utf32
cannot be used as a client character set, which means that
they also do not work for SET
NAMES
or SET CHARACTER
SET
.
Property | Value |
---|---|
System Variable | character_set_connection |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | utf8 |
The character set used for literals that do not have a character set introducer and for number-to-string conversion. For information about introducers, see Section 10.3.8, “Character Set Introducers”.
Property | Value |
---|---|
System Variable | character_set_database |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | latin1 |
Footnote | This option is dynamic, but only the server should set this information. You should not set the value of this variable manually. |
The character set used by the default database. The server
sets this variable whenever the default database changes. If
there is no default database, the variable has the same value
as character_set_server
.
The global
character_set_database
and
collation_database
system
variables are deprecated and will be removed in a future
version of MySQL.
Assigning a value to the session
character_set_database
and
collation_database
system
variables is deprecated and assignments produce a warning. The
session variables will become read only in a future version of
MySQL and assignments will produce an error. It will remain
possible to access the session variables to determine the
database character set and collation for the default database.
Property | Value |
---|---|
Command-Line Format | --character-set-filesystem=name |
System Variable | character_set_filesystem |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value | binary |
The file system character set. This variable is used to
interpret string literals that refer to file names, such as in
the LOAD DATA
INFILE
and
SELECT ... INTO
OUTFILE
statements and the
LOAD_FILE()
function. Such file
names are converted from
character_set_client
to
character_set_filesystem
before the file opening attempt occurs. The default value is
binary
, which means that no conversion
occurs. For systems on which multibyte file names are
permitted, a different value may be more appropriate. For
example, if the system represents file names using UTF-8, set
character_set_filesystem
to
'utf8'
.
Property | Value |
---|---|
System Variable | character_set_results |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | utf8 |
The character set used for returning query results such as result sets or error messages to the client.
Property | Value |
---|---|
Command-Line Format | --character-set-server |
System Variable | character_set_server |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4 |
Default Value (8.0.0) | latin1 |
The server's default character set.
Property | Value |
---|---|
System Variable | character_set_system |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | string |
Default Value | utf8 |
The character set used by the server for storing identifiers.
The value is always utf8
.
Property | Value |
---|---|
Command-Line Format | --character-sets-dir=dir_name |
System Variable | character_sets_dir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The directory where character sets are installed.
Property | Value |
---|---|
Command-Line Format | --check-proxy-users=[={OFF|ON}] |
System Variable | check_proxy_users |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Some authentication plugins implement proxy user mapping for
themselves (for example, the PAM and Windows authentication
plugins). Other authentication plugins do not support proxy
users by default. Of these, some can request that the MySQL
server itself map proxy users according to granted proxy
privileges: mysql_native_password
,
sha256_password
.
If the check_proxy_users
system variable is enabled, the server performs proxy user
mapping for any authentication plugins that make such a
request. However, it may also be necessary to enable
plugin-specific system variables to take advantage of server
proxy user mapping support:
For the mysql_native_password
plugin,
enable
mysql_native_password_proxy_users
.
For the sha256_password
plugin, enable
sha256_password_proxy_users
.
For information about user proxying, see Section 6.3.11, “Proxy Users”.
Property | Value |
---|---|
System Variable | collation_connection |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
The collation of the connection character set.
Property | Value |
---|---|
System Variable | collation_database |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4_0900_ai_ci |
Default Value (8.0.0) | latin1_swedish_ci |
Footnote | This option is dynamic, but only the server should set this information. You should not set the value of this variable manually. |
The collation used by the default database. The server sets
this variable whenever the default database changes. If there
is no default database, the variable has the same value as
collation_server
.
The global
character_set_database
and
collation_database
system
variables are deprecated and will be removed in a future
version of MySQL.
Assigning a value to the session
character_set_database
and
collation_database
system
variables is deprecated and assignments produce a warning. The
session variables will become read only in a future version of
MySQL and assignments will produce an error. It will remain
possible to access the session variables to determine the
database character set and collation for the default database.
Property | Value |
---|---|
Command-Line Format | --collation-server |
System Variable | collation_server |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (>= 8.0.1) | utf8mb4_0900_ai_ci |
Default Value (8.0.0) | latin1_swedish_ci |
The server's default collation.
Property | Value |
---|---|
Command-Line Format | --completion-type=# |
System Variable | completion_type |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | NO_CHAIN |
Valid Values |
|
The transaction completion type. This variable can take the values shown in the following table. The variable can be assigned using either the name values or corresponding integer values.
Value | Description |
---|---|
NO_CHAIN (or 0) |
COMMIT and
ROLLBACK
are unaffected. This is the default value. |
CHAIN (or 1) |
COMMIT and
ROLLBACK
are equivalent to COMMIT AND CHAIN
and ROLLBACK AND CHAIN , respectively.
(A new transaction starts immediately with the same
isolation level as the just-terminated transaction.) |
RELEASE (or 2) |
COMMIT and
ROLLBACK
are equivalent to COMMIT RELEASE and
ROLLBACK RELEASE , respectively. (The
server disconnects after terminating the transaction.) |
completion_type
affects
transactions that begin with
START
TRANSACTION
or
BEGIN
and
end with COMMIT
or
ROLLBACK
. It
does not apply to implicit commits resulting from execution of
the statements listed in Section 13.3.3, “Statements That Cause an Implicit Commit”. It
also does not apply for
XA
COMMIT
,
XA
ROLLBACK
, or when
autocommit=1
.
Property | Value |
---|---|
Command-Line Format | --concurrent-insert[=#] |
System Variable | concurrent_insert |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | AUTO |
Valid Values |
|
If AUTO
(the default), MySQL permits
INSERT
and
SELECT
statements to run
concurrently for MyISAM
tables that have no
free blocks in the middle of the data file. If you start
mysqld with
--skip-new
,
this variable is set to NEVER
.
This variable can take the values shown in the following table. The variable can be assigned using either the name values or corresponding integer values.
Value | Description |
---|---|
NEVER (or 0) |
Disables concurrent inserts |
AUTO (or 1) |
(Default) Enables concurrent insert for MyISAM tables
that do not have holes |
ALWAYS (or 2) |
Enables concurrent inserts for all MyISAM tables,
even those that have holes. For a table with a hole, new
rows are inserted at the end of the table if it is in
use by another thread. Otherwise, MySQL acquires a
normal write lock and inserts the row into the hole. |
See also Section 8.11.3, “Concurrent Inserts”.
Property | Value |
---|---|
Command-Line Format | --connect-timeout=# |
System Variable | connect_timeout |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 10 |
Minimum Value | 2 |
Maximum Value | 31536000 |
The number of seconds that the mysqld
server waits for a connect packet before responding with
Bad handshake
. The default value is 10
seconds.
Increasing the
connect_timeout
value might
help if clients frequently encounter errors of the form
Lost connection to MySQL server at
'
.
XXX
', system error:
errno
Property | Value |
---|---|
System Variable | core_file |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | boolean |
Default Value | OFF |
Whether to write a core file if the server crashes. This
variable is set by the
--core-file
option.
Property | Value |
---|---|
Command-Line Format | --cte-max-recursion-depth=# |
Introduced | 8.0.3 |
System Variable | cte_max_recursion_depth |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 1000 |
Minimum Value | 0 |
Maximum Value | 4294967295 |
The common table expression (CTE) maximum recursion depth. The server terminates execution of any CTE that recurses more levels than the value of this variable. For more information, see Limiting Common Table Expression Recursion.
Property | Value |
---|---|
Command-Line Format | --datadir=dir_name |
System Variable | datadir |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | directory name |
The path to the MySQL server data directory. Relative paths
are resolved with respect to the current directory. If the
server will be started automatically (that is, in contexts for
which you cannot assume what the current directory will be),
it is best to specify the
datadir
value as an absolute
path.
This system variable was removed in MySQL 8.0.3.
This system variable was removed in MySQL 8.0.3.
Property | Value |
---|---|
Command-Line Format | --debug[=debug_options] |
System Variable | debug |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
Default Value (Windows) | d:t:i:O,\mysqld.trace |
Default Value (Unix) | d:t:i:o,/tmp/mysqld.trace |
This variable indicates the current debugging settings. It is
available only for servers built with debugging support. The
initial value comes from the value of instances of the
--debug
option given at server
startup. The global and session values may be set at runtime.
The SYSTEM_VARIABLES_ADMIN
or
SUPER
privilege is required,
even for the session value.
Assigning a value that begins with +
or
-
cause the value to added to or subtracted
from the current value:
mysql>SET debug = 'T';
mysql>SELECT @@debug;
+---------+ | @@debug | +---------+ | T | +---------+ mysql>SET debug = '+P';
mysql>SELECT @@debug;
+---------+ | @@debug | +---------+ | P:T | +---------+ mysql>SET debug = '-P';
mysql>SELECT @@debug;
+---------+ | @@debug | +---------+ | T | +---------+
For more information, see Section 28.5.3, “The DBUG Package”.
Property | Value |
---|---|
System Variable | debug_sync |
Scope | Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | string |
This variable is the user interface to the Debug Sync
facility. Use of Debug Sync requires that MySQL be configured
with the -DENABLE_DEBUG_SYNC=1
CMake option (see
Section 2.8.4, “MySQL Source-Configuration Options”). If Debug Sync
is not compiled in, this system variable is not available.
The global variable value is read only and indicates whether
the facility is enabled. By default, Debug Sync is disabled
and the value of debug_sync
is OFF
. If the server is started with
--debug-sync-timeout=
,
where N
N
is a timeout value greater
than 0, Debug Sync is enabled and the value of
debug_sync
is ON -
current signal
followed by the signal name. Also,
N
becomes the default timeout for
individual synchronization points.
The session value can be read by any user and will have the
same value as the global variable. The session value can be
set by users that have the
SYSTEM_VARIABLES_ADMIN
or
SUPER
privilege to control
synchronization points.
For a description of the Debug Sync facility and how to use synchronization points, see MySQL Internals: Test Synchronization.
Property | Value |
---|---|
Command-Line Format | --default-authentication-plugin=plugin_name |
System Variable | default_authentication_plugin |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value (>= 8.0.4) | caching_sha2_password |
Default Value (<= 8.0.3) | mysql_native_password |
Valid Values (>= 8.0.3) |
|
Valid Values (<= 8.0.2) |
|
The default authentication plugin. These values are permitted:
mysql_native_password
: Use MySQL native
passwords; see
Section 6.5.1.1, “Native Pluggable Authentication”.
sha256_password
: Use SHA-256 passwords;
see Section 6.5.1.2, “SHA-256 Pluggable Authentication”.
caching_sha2_password
: Use SHA-256
passwords; see
Section 6.5.1.3, “Caching SHA-2 Pluggable Authentication”.
In MySQL 8.0, caching_sha2_password
is
the default authentication plugin rather than
mysql_native_password
. For information
about the implications of this change for server operation
and compatibility of the server with clients and connectors,
see caching_sha2_password as the Preferred Authentication Plugin.
The
default_authentication_plugin
value affects these aspects of server operation:
It determines which authentication plugin the server
assigns to new accounts created by
CREATE USER
and
GRANT
statements that do
not explicitly specify an authentication plugin.
For an account created with the following statement, the server associates the account with the default authentication plugin and assigns the account the given password, hashed as required by that plugin:
CREATE USER ... IDENTIFIED BY 'cleartext password
';
Property | Value |
---|---|
Introduced | 8.0.11 |
System Variable | default_collation_for_utf8mb4 |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Valid Values |
|
For internal use by replication. This system variable is set
to the default collation for the utf8mb4
character set. The value of the variable is replicated from a
master to a slave so that the slave can correctly process data
originating from a master with a different default collation
for utf8mb4
. This variable is primarily
intended to support replication from a MySQL 5.7 or older
master server to a MySQL 8.0 slave server, or group
replication with a MySQL 5.7 primary node and one or more
MySQL 8.0 secondaries. The default collation for
utf8mb4
in MySQL 5.7 is
utf8mb4_general_ci
, but
utf8mb4_0900_ai_ci
in MySQL 8.0. The
variable is not present in releases earlier than MySQL 8.0, so
if the slave does not receive a value for the variable, it
assumes the master is from an earlier release and sets the
value to the previous default collation
utf8mb4_general_ci
.
The default utf8mb4
collation is used in
the following statements:
CREATE TABLE
and
ALTER TABLE
having a
CHARACTER SET utf8mb4
clause without a
COLLATION
clause, either for the table
character set or for a column character set.
CREATE DATABASE
and
ALTER DATABASE
having a
CHARACTER SET utf8mb4
clause without a
COLLATION
clause.
Any statement containing a string literal of the form
_utf8mb4'
without a
some
text
'COLLATE
clause.
Property | Value |
---|---|
Command-Line Format | --default-password-lifetime=# |
System Variable | default_password_lifetime |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 0 |
Minimum Value | 0 |
Maximum Value | 65535 |
This variable defines the global automatic password expiration
policy. The default
default_password_lifetime
value is 0, which disables automatic password expiration. If
the value of
default_password_lifetime
is
a positive integer N
, it indicates
the permitted password lifetime; passwords must be changed
every N
days.
The global password expiration policy can be overridden as
desired for individual accounts using the password expiration
option of the CREATE USER
and
ALTER USER
statements. See
Section 6.3.8, “Password Management”.
Property | Value |
---|---|
Command-Line Format | --default-storage-engine=name |
System Variable | default_storage_engine |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | InnoDB |
The default storage engine. This variable sets the storage
engine for permanent tables only. To set the storage engine
for TEMPORARY
tables, set the
default_tmp_storage_engine
system variable.
To see which storage engines are available and enabled, use
the SHOW ENGINES
statement or
query the INFORMATION_SCHEMA
ENGINES
table.
If you disable the default storage engine at server startup,
you must set the default engine for both permanent and
TEMPORARY
tables to a different engine or
the server will not start.
Property | Value |
---|---|
Command-Line Format | --default-tmp-storage-engine=name |
System Variable | default_tmp_storage_engine |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | Yes |
Type | enumeration |
Default Value | InnoDB |
The default storage engine for TEMPORARY
tables (created with
CREATE TEMPORARY
TABLE
). To set the storage engine for permanent
tables, set the
default_storage_engine
system
variable. Also see the discussion of that variable regarding
possible values.
If you disable the default storage engine at server startup,
you must set the default engine for both permanent and
TEMPORARY
tables to a different engine or
the server will not start.
Property | Value |
---|---|
Command-Line Format | --default-week-format=# |
System Variable | default_week_format |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 0 |
Minimum Value | 0 |
Maximum Value | 7 |
The default mode value to use for the
WEEK()
function. See
Section 12.7, “Date and Time Functions”.
Property | Value |
---|---|
Command-Line Format | --delay-key-write[=name] |
System Variable | delay_key_write |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | enumeration |
Default Value | ON |
Valid Values |
|
This option applies only to MyISAM
tables.
It can have one of the following values to affect handling of
the DELAY_KEY_WRITE
table option that can
be used in CREATE TABLE
statements.
Option | Description |
---|---|
OFF |
DELAY_KEY_WRITE is ignored. |
ON |
MySQL honors any DELAY_KEY_WRITE option specified in
CREATE TABLE statements.
This is the default value. |
ALL |
All new opened tables are treated as if they were created with the
DELAY_KEY_WRITE option enabled. |
If DELAY_KEY_WRITE
is enabled for a table,
the key buffer is not flushed for the table on every index
update, but only when the table is closed. This speeds up
writes on keys a lot, but if you use this feature, you should
add automatic checking of all MyISAM
tables
by starting the server with the
--myisam-recover-options
option
(for example,
--myisam-recover-options=BACKUP,FORCE
).
See Section 5.1.6, “Server Command Options”, and
Section 16.2.1, “MyISAM Startup Options”.
If you enable external locking with
--external-locking
, there is
no protection against index corruption for tables that use
delayed key writes.
Property | Value |
---|---|
Command-Line Format | --delayed-insert-limit=# |
Deprecated | Yes |
System Variable | delayed_insert_limit |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 100 |
Minimum Value | 1 |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
This system variable is deprecated (because
DELAYED
inserts are not supported), and
will be removed in a future release.
Property | Value |
---|---|
Command-Line Format | --delayed-insert-timeout=# |
Deprecated | Yes |
System Variable | delayed_insert_timeout |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 300 |
This system variable is deprecated (because
DELAYED
inserts are not supported), and
will be removed in a future release.
Property | Value |
---|---|
Command-Line Format | --delayed-queue-size=# |
Deprecated | Yes |
System Variable | delayed_queue_size |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies | No |
Type | integer |
Default Value | 1000 |
Minimum Value | 1 |
Maximum Value (64-bit platforms) | 18446744073709551615 |
Maximum Value (32-bit platforms) | 4294967295 |
This system variable is deprecated (because
DELAYED
inserts are not supported), and
will be removed in a future release.
Property | Value |
---|---|
Command-Line Format | --disabled-storage-engines=engine[,engine]... |
System Variable | disabled_storage_engines |
Scope | Global |
Dynamic |