System Variables for MariaDB Enterprise Server 10.5

Overview

MariaDB Enterprise Server can be configured using system variables.

Reference material is available for MariaDB Enterprise Server 10.5.

USAGE

There are many different ways to use system variables.

Set in a Configuration File

If the specific system variable is not read-only, you can set it in a MariaDB configuration file (such as my.cnf):

[mariadb]
log_error=/var/log/mariadb/mariadb.err

Read All Values from Configuration Files

All system variables and other mariadbd command-line options in the system's MariaDB configuration file (such as my.cnf) can be read using the my_print_defaults utility with the --mysqld option:

$ my_print_defaults --mysqld

Set on the Command-Line

If the specific system variable has a corresponding mariadbd command-line option, you can set it when the server is started:

$ mariadbd --log_error=/var/log/mariadb/mariadb.err [OPTION ...]

Set the Global Value Dynamically

Changes made dynamically with SET GLOBAL are not durable and will be lost when the server is stopped. To be durable, changes must be set in the configuration file.

A global variable change affects new sessions. It does not affect any currently open sessions, including the session used to make the change.

If the specific system variable is dynamic, you can set its global value with the SET GLOBAL statement:

SET GLOBAL log_warnings=3;

Show All Global Values

All global system variables can be queried with the SHOW GLOBAL VARIABLES statement:

SHOW GLOBAL VARIABLES;

Set the Session Value Dynamically

If the specific system variable supports session-specific values, you can set its session value with the SET SESSION statement:

SET SESSION log_warnings=3;

Show All Session Values

All system variables for the current session can be queried with the SHOW SESSION VARIABLES statement:

SHOW SESSION VARIABLES;

Show Values with a Filter

It is also possible to filter the output of SHOW VARIABLES, so that it does not return all values.

The SHOW VARIABLES statements can be filtered with a LIKE clause:

SHOW GLOBAL VARIABLES
   LIKE 'log_%';

The SHOW VARIABLES statements can also be filtered with a WHERE clause:

SHOW GLOBAL VARIABLES
   WHERE Variable_name IN(
      'log_error',
      'log_warnings'
   );

Reference Values in a Query

A specific global or session system variable can be referenced in a query by prefixing the variable name with @@global. or @@session.:

SELECT @@session.log_warnings,
   @@global.log_error;

DETAILS

MariaDB Enterprise Server supports many system variables.

System Variables for MariaDB Enterprise Server 10.5

Variable

Description

alter_algorithm

Configures the server to use specific algorithms for ALTER TABLE operations

analyze_sample_percentage

Percentage of rows from the table ANALYZE TABLE will sample to collect table statistics. Set to 0 to let MariaDB decide what percentage of rows to sample.

aria_block_size

Block size to be used for Aria index pages

aria_checkpoint_interval

Interval between tries to do an automatic checkpoints. In seconds; 0 means 'no automatic checkpoints' which makes sense only for testing.

aria_checkpoint_log_activity

Number of bytes that the transaction log has to grow between checkpoints before a new checkpoint is written to the log

aria_encrypt_tables

Encrypt tables (only for tables with ROW_FORMAT=PAGE (default) and not FIXED/DYNAMIC)

aria_force_start_after_recovery_failures

Number of consecutive log recovery failures after which logs will be automatically deleted to cure the problem; 0 (the default) disables the feature

aria_group_commit

Specifies Aria group commit mode. Possible values are "none" (no group commit), "hard" (with waiting to actual commit), "soft" (no wait for commit (DANGEROUS!!!))

aria_group_commit_interval

Interval between commits in microseconds (1/1000000 sec). 0 stands for no waiting for other threads to come and do a commit in "hard" mode and no sync()/commit at all in "soft" mode. Option has only an effect if aria_group_commit is used

aria_log_dir_path

Path to the directory where to store transactional log

aria_log_file_size

Limit for transaction log size

aria_log_purge_type

Specifies how Aria transactional log will be purged

aria_max_sort_file_size

Don't use the fast sort index method to created index if the temporary file would get bigger than this

aria_page_checksum

Maintain page checksums (can be overridden per table with PAGE_CHECKSUM clause in CREATE TABLE)

aria_pagecache_age_threshold

This characterizes the number of hits a hot block has to be untouched until it is considered aged enough to be downgraded to a warm block. This specifies the percentage ratio of that number of hits to the total number of blocks in the page cache.

aria_pagecache_buffer_size

The size of the buffer used for index blocks for Aria tables. Increase this to get better index handling (for all reads and multiple writes) to as much as you can afford.

aria_pagecache_division_limit

The minimum percentage of warm blocks in key cache

aria_pagecache_file_hash_size

Number of hash buckets for open and changed files. If you have a lot of Aria files open you should increase this for faster flush of changes. A good value is probably 1/10 of number of possible open Aria files.

aria_recover_options

Specifies how corrupted tables should be automatically repaired

aria_repair_threads

Number of threads to use when repairing Aria tables. The value of 1 disables parallel repair.

aria_sort_buffer_size

The buffer that is allocated when sorting the index when doing a REPAIR or when creating indexes with CREATE INDEX or ALTER TABLE

aria_stats_method

Specifies how Aria index statistics collection code should treat NULLs

aria_sync_log_dir

Controls syncing directory after log file growth and new file creation

aria_used_for_temp_tables

Whether temporary tables should be MyISAM or Aria

auto_increment_increment

Auto-increment columns are incremented by this

auto_increment_offset

Offset added to Auto-increment columns. Used when auto-increment-increment != 1

autocommit

For an implicit transaction containing a SQL statement that modifies a table, the autocommit system variable specifies whether commit should be automatic upon successful statement execution

automatic_sp_privileges

Creating and dropping stored procedures alters ACLs

aws_key_management_key_spec

Encryption algorithm used to create new keys

aws_key_management_log_level

Dump log of the AWS SDK to MariaDB error log. Permitted values, in increasing verbosity, are Off (default), Fatal, Error, Warn, Info, Debug, and Trace.

aws_key_management_master_key_id

AWS KMS Customer Master Key ID (ARN or alias prefixed by alias/) for the master encryption key. Used to create new data keys. If not set, no new data keys will be created.

aws_key_management_mock

Mock AWS KMS calls (for testing). Must be enabled at compile-time.

aws_key_management_region

AWS region name, e.g., us-east-1 . Default is SDK default, which is us-east-1.

aws_key_management_request_timeout

Timeout in milliseconds for create HTTPS connection or execute AWS request. Specify 0 to use SDK default.

aws_key_management_rotate_key

Set this variable to a data key ID to perform rotation of the key to the master key given in aws_key_management_master_key_id. Specify -1 to rotate all keys.

back_log

The number of outstanding connection requests MariaDB can have. This comes into play when the main MariaDB thread gets very many connection requests in a very short time

basedir

Path to installation directory. All paths are usually resolved relative to this

big_tables

Old variable, which if set to 1, allows large result sets by saving all temporary sets to disk, avoiding 'table full' errors. No longer needed, as the server now handles this automatically.

bind_address

IP address to bind to

binlog_annotate_row_events

Tells the master to annotate RBR events with the statement that caused these events

binlog_cache_size

The size of the transactional cache for updates to transactional engines for the binary log. If you often use transactions containing many statements, you can increase this to get more performance

binlog_checksum

Type of BINLOG_CHECKSUM_ALG. Include checksum for log events in the binary log

binlog_commit_wait_count

If non-zero, binlog write will wait at most binlog_commit_wait_usec microseconds for at least this many commits to queue up for group commit to the binlog. This can reduce I/O on the binlog and provide increased opportunity for parallel apply on the slave, but too high a value will decrease commit throughput.

binlog_commit_wait_usec

Maximum time, in microseconds, to wait for more commits to queue up for binlog group commit. Only takes effect if the value of binlog_commit_wait_count is non-zero.

binlog_direct_non_transactional_updates

Causes updates to non-transactional engines using statement format to be written directly to binary log. Before using this option make sure that there are no dependencies between transactional and non-transactional tables such as in the statement INSERT INTO t_myisam SELECT * FROM t_innodb; otherwise, slaves may diverge from the master.

binlog_file_cache_size

The size of file cache for the binary log

binlog_format

What form of binary logging the master will use: either ROW for row-based binary logging, STATEMENT for statement-based binary logging, or MIXED. MIXED is statement-based binary logging except for those statements where only row-based is correct: those which involve user-defined functions (i.e., UDFs) or the UUID() function; for those, row-based binary logging is automatically used.

binlog_optimize_thread_scheduling

Run fast part of group commit in a single thread, to optimize kernel thread scheduling. On by default. Disable to run each transaction in group commit in its own thread, which can be slower at very high concurrency. This option is mostly for testing one algorithm versus the other, and it should not normally be necessary to change it.

binlog_row_image

Controls whether rows should be logged in 'FULL', 'NOBLOB' or 'MINIMAL' formats. 'FULL', means that all columns in the before and after image are logged. 'NOBLOB', means that mysqld avoids logging blob columns whenever possible (e.g., blob column was not changed or is not part of primary key). 'MINIMAL', means that a PK equivalent (PK columns or full row if there is no PK in the table) is logged in the before image, and only changed columns are logged in the after image. (Default: FULL).

binlog_row_metadata

Controls whether metadata is logged using FULL , MINIMAL format and NO_LOG.FULL causes all metadata to be logged; MINIMAL means that only metadata actually required by slave is logged; NO_LOG NO metadata will be logged.Default: NO_LOG

binlog_stmt_cache_size

The size of the statement cache for updates to non-transactional engines for the binary log. If you often use statements updating a great number of rows, you can increase this to get more performance.

bulk_insert_buffer_size

Size of tree cache used in bulk insert optimisation. Note that this is a limit per thread!

character_set_client

The character set for statements that arrive from the client

character_set_connection

The character set used for literals that do not have a character set introducer and for number-to-string conversion

character_set_database

The character set used by the default database

character_set_filesystem

The filesystem character set

character_set_results

The character set used for returning query results to the client

character_set_server

The default character set

character_set_system

The character set used by the server for storing identifiers

character_sets_dir

Directory where character sets are

check_constraint_checks

check_constraint_checks

collation_connection

The collation of the connection character set

collation_database

The collation of the database character set

collation_server

The server default collation

column_compression_threshold

Minimum column data length eligible for compression

column_compression_zlib_level

zlib compression level (1 gives best speed, 9 gives best compression)

column_compression_zlib_strategy

The strategy parameter is used to tune the compression algorithm. Use the value DEFAULT_STRATEGY for normal data, FILTERED for data produced by a filter (or predictor), HUFFMAN_ONLY to force Huffman encoding only (no string match), or RLE to limit match distances to one (run-length encoding). Filtered data consists mostly of small values with a somewhat random distribution. In this case, the compression algorithm is tuned to compress them better. The effect of FILTERED is to force more Huffman coding and less string matching; it is somewhat intermediate between DEFAULT_STRATEGY and HUFFMAN_ONLY. RLE is designed to be almost as fast as HUFFMAN_ONLY, but give better compression for PNG image data. The strategy parameter only affects the compression ratio but not the correctness of the compressed output even if it is not set appropriately. FIXED prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.

column_compression_zlib_wrap

Generate zlib header and trailer and compute adler32 check value. It can be used with storage engines that don't provide data integrity verification to detect data corruption.

columnstore_cache_flush_threshold

Threshold on the number of rows in the cache to trigger a flush

columnstore_cache_inserts

Perform cache-based inserts to ColumnStore

columnstore_compression_type

Controls compression algorithm for create tables. Possible values are: NO_COMPRESSION segment files aren't compressed; SNAPPY segment files are Snappy compressed (default);

columnstore_decimal_scale

The default decimal precision for calculated column sub-operations

columnstore_derived_handler

Enable/Disable the MCS derived_handler

columnstore_diskjoin_bucketsize

The maximum size in MB of each 'small side' table in memory

columnstore_diskjoin_largesidelimit

The maximum amount of disk space in MB to use per join for storing 'large side' table data for a disk-based join. (0 = unlimited)

columnstore_diskjoin_smallsidelimit

The maximum amount of disk space in MB to use per query for storing 'small side' tables for a disk-based join. (0 = unlimited)

columnstore_double_for_decimal_math

Enable/disable for ColumnStore to replace DECIMAL with DOUBLE in arithmetic operation

columnstore_group_by_handler

Enable/Disable the MCS group_by_handler

columnstore_import_for_batchinsert_delimiter

ASCII value of the delimiter used by LDI and INSERT..SELECT

columnstore_import_for_batchinsert_enclosed_by

ASCII value of the quote symbol used by batch data ingestion

columnstore_local_query

Enable/disable the ColumnStore local PM query only feature

columnstore_orderby_threads

Number of parallel threads used by ORDER BY. (default to 16)

columnstore_ordered_only

Always use the first table in the from clause as the large side table for joins

columnstore_replication_slave

Allow this MariaDB server to apply replication changes to ColumnStore

columnstore_select_handler

Enables the ColumnStore select handler, which allows ColumnStore to plan its own queries

columnstore_select_handler_in_stored_procedures

Enable/Disable the MCS select_handler for Stored Procedures

columnstore_string_scan_threshold

Max number of blocks in a dictionary file to be scanned for filtering

columnstore_stringtable_threshold

The minimum width of a string column to be stored in a string table

columnstore_um_mem_limit

Per user Memory limit(MB). Switch to disk-based JOIN when limit is reached

columnstore_use_decimal_scale

Enable/disable the MCS decimal scale to be used internally

columnstore_use_import_for_batchinsert

LOAD DATA INFILE and INSERT..SELECT will use cpimport internally

columnstore_varbin_always_hex

Always display/process varbinary columns as if they have been hexified

completion_type

The transaction completion type

concurrent_insert

Use concurrent insert with MyISAM

connect_timeout

The number of seconds the mysqld server is waiting for a connect packet before responding with 'Bad handshake'

core_file

Write core on crashes

cracklib_password_check_dictionary

Path to a cracklib dictionary

datadir

Path to the database root directory

date_format

The DATE format (ignored)

datetime_format

The DATETIME format (ignored)

deadlock_search_depth_long

Long search depth for the two-step deadlock detection

deadlock_search_depth_short

Short search depth for the two-step deadlock detection

deadlock_timeout_long

Long timeout for the two-step deadlock detection (in microseconds)

deadlock_timeout_short

Short timeout for the two-step deadlock detection (in microseconds)

debug

Available in debug builds only (built with -SWITH_DEBUG=1). Used in debugging through the DBUG library to write to a trace file. Just using --debug will write a trace of what mysqld is doing to /tmp/mysqld.trace.

debug_no_thread_alarm

Disable system thread alarm calls. Disabling it may be useful in debugging or testing, never do it in production

debug_sync

Used in debugging to show the interface to the Debug Sync facility. MariaDB needs to be configured with -DENABLE_DEBUG_SYNC=1 for this variable to be available.

default_master_connection

Master connection to use for all slave variables and slave commands

default_password_lifetime

This defines the global password expiration policy. 0 means automatic password expiration is disabled. If the value is a positive integer N, the passwords must be changed every N days. This behavior can be overridden using the password expiration options in ALTER USER.

default_regex_flags

Default flags for the regex library

default_storage_engine

The default storage engine for new tables

default_tmp_storage_engine

The default storage engine for user-created temporary tables

default_week_format

The default week format used by WEEK() functions

delay_key_write

Specifies how MyISAM tables handles CREATE TABLE DELAY_KEY_WRITE. If set to ON, the default, any DELAY KEY WRITEs are honored. The key buffer is then flushed only when the table closes, speeding up writes. MyISAM tables should be automatically checked upon startup in this case, and --external locking should not be used, as it can lead to index corruption. If set to OFF, DELAY KEY WRITEs are ignored, while if set to ALL, all new opened tables are treated as if created with DELAY KEY WRITEs enabled.

delayed_insert_limit

After inserting delayed_insert_limit rows, the INSERT DELAYED handler will check if there are any SELECT statements pending. If so, it allows these to execute before continuing.

delayed_insert_timeout

How long a INSERT DELAYED thread should wait for INSERT statements before terminating

delayed_queue_size

What size queue (in rows) should be allocated for handling INSERT DELAYED. If the queue becomes full, any client that does INSERT DELAYED will wait until there is room in the queue again

disconnect_on_expired_password

This variable controls how the server handles clients that are not aware of the sandbox mode. If enabled, the server disconnects the client, otherwise the server puts the client in a sandbox mode.

div_precision_increment

Precision of the result of '/' operator will be increased on that value

encrypt_binlog

Encrypt binary logs (including relay logs)

encrypt_tmp_disk_tables

Encrypt temporary on-disk tables (created as part of query execution)

encrypt_tmp_files

Encrypt temporary files (created for filesort, binary log cache, etc)

enforce_storage_engine

Force the use of a storage engine for new tables

eq_range_index_dive_limit

The optimizer will use existing index statistics instead of doing index dives for equality ranges if the number of equality ranges for the index is larger than or equal to this number. If set to 0, index dives are always used.

error_count

The number of errors that resulted from the last statement that generated messages

event_scheduler

Enable the event scheduler. Possible values are ON, OFF, and DISABLED (keep the event scheduler completely deactivated, it cannot be activated run-time)

expensive_subquery_limit

The maximum number of rows a subquery may examine in order to be executed during optimization and used for constant optimization

expire_logs_days

If non-zero, binary logs will be purged after expire_logs_days days; possible purges happen at startup and at binary log rotation

explicit_defaults_for_timestamp

This option causes CREATE TABLE to create all TIMESTAMP columns as NULL with DEFAULT NULL attribute, Without this option, TIMESTAMP columns are NOT NULL and have implicit DEFAULT clauses

external_user

The external user account used when logging in

extra_max_connections

The number of connections on extra-port

extra_port

Extra port number to use for tcp connections in a one-thread-per-connection manner. 0 means don't use another port

feedback_http_proxy

Proxy server host:port

feedback_send_retry_wait

Wait this many seconds before retrying a failed send

feedback_send_timeout

Timeout (in seconds) for the sending the report

feedback_server_uid

Automatically calculated server unique id hash

feedback_url

Space separated URLs to send the feedback report to

feedback_user_info

User specified string that will be included in the feedback report

file_key_management_encryption_algorithm

Encryption algorithm to use, aes_ctr is the recommended one

file_key_management_filekey

Key to encrypt / decrypt the keyfile

file_key_management_filename

Path and name of the key file

flush

Flush MyISAM tables to disk between SQL commands

flush_time

A dedicated thread is created to flush all tables at the given interval

foreign_key_checks

If set to 1 (the default) foreign key constraints (including ON UPDATE and ON DELETE behavior) InnoDB tables are checked, while if set to 0, they are not checked. 0 is not recommended for normal use, though it can be useful in situations where you know the data is consistent, but want to reload data in a different order from that that specified by parent/child relationships. Setting this variable to 1 does not retrospectively check for inconsistencies introduced while set to 0.

ft_boolean_syntax

List of operators for MATCH ... AGAINST ( ... IN BOOLEAN MODE)

ft_max_word_len

The maximum length of the word to be included in a FULLTEXT index. Note: FULLTEXT indexes must be rebuilt after changing this variable

ft_min_word_len

The minimum length of the word to be included in a FULLTEXT index. Note: FULLTEXT indexes must be rebuilt after changing this variable

ft_query_expansion_limit

Number of best matches to use for query expansion

ft_stopword_file

Use stopwords from this file instead of built-in list

general_log

Log connections and queries to a table or log file. Defaults logging to a file 'hostname'.log or a table mysql.general_logif --log-output=TABLE is used.

general_log_file

Log connections and queries to given file

group_concat_max_len

The maximum length of the result of function GROUP_CONCAT()

gssapi_keytab_path

Defines the path to the server's keytab file. This system variable is only meaningful on Unix. See Creating a Keytab File on a Unix Server for more information.

gssapi_mech_name

Name of the SSPI package used by server. Can be either 'Kerberos' or 'Negotiate'. Set it to 'Kerberos', to prevent less secure NTLM in domain environments, but leave it as default (Negotiate) to allow non-domain environments (e.g., if server does not run in a domain environment). This system variable is only meaningful on Windows.

gssapi_principal_name

Name of the service principal

gtid_binlog_pos

Last GTID logged to the binary log, per replicationdomain

gtid_binlog_state

The internal GTID state of the binlog, used to keep track of all GTIDs ever logged to the binlog

gtid_cleanup_batch_size

Normally does not need tuning. How many old rows must accumulate in the mysql.gtid_slave_pos table before a background job will be run to delete them. Can be increased to reduce number of commits if using many different engines with --gtid_pos_auto_engines, or to reduce CPU overhead if using a huge number of different gtid_domain_ids. Can be decreased to reduce number of old rows in the table.

gtid_current_pos

Current GTID position of the server. Per replication domain, this is either the last GTID replicated by a slave thread, or the GTID logged to the binary log, whichever is most recent.

gtid_domain_id

Used with global transaction ID to identify logically independent replication streams. When events can propagate through multiple parallel paths (for example multiple masters), each independent source server must use a distinct domain_id. For simple tree-shaped replication topologies, it can be left at its default, 0.

gtid_ignore_duplicates

When set, different master connections in multi-source replication are allowed to receive and process event groups with the same GTID (when using GTID mode). Only one will be applied, any others will be ignored. Within a given replication domain, just the sequence number will be used to decide whether a given GTID has been already applied; this means it is the responsibility of the user to ensure that GTID sequence numbers are strictly increasing.

gtid_pos_auto_engines

List of engines for which to automatically create a mysql.gtid_slave_pos_ENGINE table, if a transaction using that engine is replicated. This can be used to avoid introducing cross-engine transactions, if engines are used different from that used by table mysql.gtid_slave_pos

gtid_seq_no

Internal server usage, for replication with global transaction id. When set, next event group logged to the binary log will use this sequence number, not generate a new one, thus allowing to preserve master's GTID in slave's binlog.

gtid_slave_pos

The list of global transaction IDs that were last replicated on the server, one for each replication domain

gtid_strict_mode

Enforce strict seq_no ordering of events in the binary log. Slave stops with an error if it encounters an event that would cause it to generate an out-of-order binlog if executed. When ON the same server-id semisync-replicated transactions that duplicate exising ones in binlog are ignored without error and slave interruption.

hashicorp_key_management_cache_timeout

Cache timeout for key data (in milliseconds)

hashicorp_key_management_cache_version_timeout

Cache timeout for key version (in milliseconds)

hashicorp_key_management_caching_enabled

Enable key caching (storing key values received from the Hashicorp Vault server in the local memory)

hashicorp_key_management_check_kv_version

Enable kv storage version check during plugin initialization

hashicorp_key_management_max_retries

Number of server request retries in case of timeout

hashicorp_key_management_timeout

Duration (in seconds) for the Hashicorp Vault server connection timeout

hashicorp_key_management_use_cache_on_timeout

In case of timeout (when accessing the vault server) use the value taken from the cache

hashicorp_key_management_vault_ca

Path to the Certificate Authority (CA) bundle (is a file that contains root and intermediate certificates)

hashicorp_key_management_vault_url

HTTP[s] URL that is used to connect to the Hashicorp Vault server

have_compress

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

have_crypt

If the crypt() system call is available this variable will be set to YES, otherwise it will be set to NO. If set to NO, the ENCRYPT() function cannot be used.

have_dynamic_loading

If the server supports dynamic loading of plugins, will be set to YES, otherwise will be set to NO

have_geometry

If the server supports spatial data types, will be set to YES, otherwise will be set to NO

have_openssl

Comparing have_openssl with have_ssl will indicate whether YaSSL or openssl was used. If YaSSL, have_ssl will be YES, but have_openssl will be NO.

have_profiling

If statement profiling is available, will be set to YES, otherwise will be set to NO. See SHOW PROFILES and SHOW PROFILE.

have_query_cache

If the server supports the query cache, will be set to YES, otherwise will be set to NO

have_rtree_keys

If RTREE indexes (used for spatial indexes) are available, will be set to YES, otherwise will be set to NO

have_ssl

If the server supports secure connections, will be set to YES, otherwise will be set to NO. If set to DISABLED, the server was compiled with TLS support, but was not started with TLS support (see the mysqld options). See also have_openssl.

have_symlink

If symbolic link support is enabled, will be set to YES, otherwise will be set to NO. Required for the INDEX DIRECTORY and DATA DIRECTORY table options (see CREATE TABLE) and Windows symlink support. Will be set to DISABLED if the server is started with the --skip-symbolic-links option.

histogram_size

Number of bytes used for a histogram. If set to 0, no histograms are created by ANALYZE.

histogram_type

Specifies type of the histograms created by ANALYZE. Possible values are: SINGLE_PREC_HB - single precision height-balanced, DOUBLE_PREC_HB - double precision height-balanced.

host_cache_size

How many host names should be cached to avoid resolving

hostname

Server host name

identity

Synonym for the last_insert_id variable

idle_readonly_transaction_timeout

The number of seconds the server waits for read-only idle transaction

idle_transaction_timeout

The number of seconds the server waits for idle transaction

idle_write_transaction_timeout

The number of seconds the server waits for write idle transaction

ignore_builtin_innodb

Disable initialization of builtin InnoDB plugin

ignore_db_dirs

Specifies a directory to add to the ignore list when collecting database names from the datadir. Put a blank argument to reset the list accumulated so far.

in_predicate_conversion_threshold

The minimum number of scalar elements in the value list of IN predicate that triggers its conversion to IN subquery. Set to 0 to disable the conversion.

in_transaction

Whether there is an active transaction

inet6

Plugin variable (version 1.0)

init_connect

Command(s) that are executed for each new connection (unless the user has SUPER privilege)

init_file

Read SQL commands from this file at startup

init_slave

Command(s) that are executed by a slave server each time the SQL thread starts

innodb_adaptive_checkpoint

Replaced with innodb_adaptive_flushing_method

innodb_adaptive_flushing

Attempt flushing dirty pages to avoid IO bursts at checkpoints

innodb_adaptive_flushing_lwm

Percentage of log capacity below which no adaptive flushing happens

innodb_adaptive_hash_index

Enable InnoDB adaptive hash index (disabled by default)

innodb_adaptive_hash_index_parts

Number of InnoDB Adaptive Hash Index Partitions (default 8)

innodb_adaptive_max_sleep_delay

Deprecated parameter with no effect

innodb_autoextend_increment

Data file autoextend increment in megabytes

innodb_autoinc_lock_mode

The AUTOINC lock modes supported by InnoDB: 0 => Old style AUTOINC locking (for backward compatibility); 1 => New style AUTOINC locking; 2 => No AUTOINC locking (unsafe for SBR)

innodb_background_scrub_data_check_interval

Deprecated parameter with no effect

innodb_background_scrub_data_compressed

Deprecated parameter with no effect

innodb_background_scrub_data_interval

Deprecated parameter with no effect

innodb_background_scrub_data_uncompressed

Deprecated parameter with no effect

innodb_buf_dump_status_frequency

A number between [0, 100] that tells how oftern buffer pool dump status in percentages should be printed. E.g. 10 means that buffer pool dump status is printed when every 10% of number of buffer pool pages are dumped. Default is 0 (only start and end status is printed).

innodb_buffer_pool_chunk_size

Size of a single memory chunk for resizing buffer pool. Online buffer pool resizing happens at this granularity. 0 means disable resizing buffer pool.

innodb_buffer_pool_dump_at_shutdown

Dump the buffer pool into a file named @@innodb_buffer_pool_filename

innodb_buffer_pool_dump_now

Trigger an immediate dump of the buffer pool into a file named @@innodb_buffer_pool_filename

innodb_buffer_pool_dump_pct

Dump only the hottest N% of each buffer pool, defaults to 25

innodb_buffer_pool_evict

Used in testing InnoDB Buffer Pool

innodb_buffer_pool_filename

Filename to/from which to dump/load the InnoDB buffer pool

innodb_buffer_pool_instances

Deprecated parameter with no effect

innodb_buffer_pool_load_abort

Abort a currently running load of the buffer pool

innodb_buffer_pool_load_at_startup

Load the buffer pool from a file named @@innodb_buffer_pool_filename

innodb_buffer_pool_load_now

Trigger an immediate load of the buffer pool from a file named @@innodb_buffer_pool_filename

innodb_buffer_pool_size

The size of the memory buffer InnoDB uses to cache data and indexes of its tables

innodb_change_buffer_max_size

Maximum on-disk size of change buffer in terms of percentage of the buffer pool

innodb_change_buffering

Buffer changes to secondary indexes

innodb_change_buffering_debug

Used in debugging builds for InnoDB

innodb_checksum_algorithm

The algorithm InnoDB uses for page checksumming. Possible values are FULL_CRC32 for new files, always use CRC-32C; for old, see CRC32 below; STRICT_FULL_CRC32 for new files, always use CRC-32C; for old, see STRICT_CRC32 below; CRC32 write crc32, allow any of the other checksums to match when reading; STRICT_CRC32 write crc32, do not allow other algorithms to match when reading; INNODB write a software calculated checksum, allow any other checksums to match when reading; STRICT_INNODB write a software calculated checksum, do not allow other algorithms to match when reading; NONE write a constant magic number, do not do any checksum verification when reading (same as innodb_checksums=OFF); STRICT_NONE write a constant magic number, do not allow values other than that magic number when reading; Files updated when this option is set to crc32 or strict_crc32 will not be readable by MariaDB versions older than 10.0.4; new files created with full_crc32 are readable by MariaDB 10.4.3+

innodb_cmp_per_index_enabled

Enable INFORMATION_SCHEMA.innodb_cmp_per_index, may have negative impact on performance (off by default)

innodb_commit_concurrency

Deprecated parameter with no effect

innodb_compression_algorithm

Compression algorithm used on page compression. One of: none, zlib, lz4, lzo, lzma, bzip2, or snappy

innodb_compression_default

Is compression the default for new tables

innodb_compression_failure_threshold_pct

If the compression failure rate of a table is greater than this number more padding is added to the pages to reduce the failures. A value of zero implies no padding

innodb_compression_level

Compression level used for zlib compression. 0 is no compression, 1 is fastest, 9 is best compression and default is 6.

innodb_compression_pad_pct_max

Percentage of empty space on a data page that can be reserved to make the page compressible

innodb_concurrency_tickets

Deprecated parameter with no effect

innodb_data_file_path

Path to individual files and their sizes

innodb_data_home_dir

The common part for InnoDB table spaces

innodb_deadlock_detect

Enable/disable InnoDB deadlock detector (default ON). if set to OFF, deadlock detection is skipped, and we rely on innodb_lock_wait_timeout in case of deadlock.

innodb_default_encryption_key_id

Default encryption key id used for table encryption

innodb_default_row_format

The default ROW FORMAT for all innodb tables created without explicit ROW_FORMAT. Possible values are REDUNDANT, COMPACT, and DYNAMIC. The ROW_FORMAT value COMPRESSED is not allowed

innodb_defragment

Enable/disable InnoDB defragmentation (default FALSE). When set to FALSE, all existing defragmentation will be paused. And new defragmentation command will fail.Paused defragmentation commands will resume when this variable is set to true again.

innodb_defragment_fill_factor

A number between [0.7, 1] that tells defragmentation how full it should fill a page. Default is 0.9. Number below 0.7 won't make much sense.This variable, together with innodb_defragment_fill_factor_n_recs, is introduced so defragmentation won't pack the page too full and cause page split on the next insert on every page. The variable indicating more defragmentation gain is the one effective.

innodb_defragment_fill_factor_n_recs

How many records of space defragmentation should leave on the page. This variable, together with innodb_defragment_fill_factor, is introduced so defragmentation won't pack the page too full and cause page split on the next insert on every page. The variable indicating more defragmentation gain is the one effective.

innodb_defragment_frequency

Do not defragment a single index more than this number of time per second.This controls the number of time defragmentation thread can request X_LOCK on an index. Defragmentation thread will check whether 1/defragment_frequency (s) has passed since it worked on this index last time, and put the index back to the queue if not enough time has passed. The actual frequency can only be lower than this given number.

innodb_defragment_n_pages

Number of pages considered at once when merging multiple pages to defragment

innodb_defragment_stats_accuracy

How many defragment stats changes there are before the stats are written to persistent storage. Set to 0 meaning disable defragment stats tracking.

innodb_disable_sort_file_cache

Whether to disable OS system file cache for sort I/O

innodb_doublewrite

Enable InnoDB doublewrite buffer (enabled by default). Disable with --skip-innodb-doublewrite.

innodb_encrypt_log

Enable redo log encryption

innodb_encrypt_tables

Enable encryption for tables. Don't forget to enable --innodb-encrypt-log too

innodb_encrypt_temporary_tables

Enrypt the temporary table data

innodb_encryption_rotate_key_age

Key rotation - re-encrypt in background all pages that were encrypted with a key that many (or more) versions behind. Value 0 indicates that key rotation is disabled.

innodb_encryption_rotation_iops

Use this many iops for background key rotation

innodb_encryption_threads

Number of threads performing background key rotation

innodb_fast_shutdown

Speeds up the shutdown process of the InnoDB storage engine. Possible values are 0, 1 (faster), 2 (crash-like), 3 (fastest clean).

innodb_fatal_semaphore_wait_threshold

Maximum number of seconds that semaphore times out in InnoDB

innodb_file_format

Deprecated parameter with no effect

innodb_file_per_table

Stores each InnoDB table to an .ibd file in the database dir

innodb_fill_factor

Percentage of B-tree page filled during bulk insert

innodb_flush_log_at_timeout

Write and flush logs every (n) second

innodb_flush_log_at_trx_commit

Controls the durability/speed trade-off for commits. Set to 0 (write and flush redo log to disk only once per second), 1 (flush to disk at each commit), 2 (write to log at commit but flush to disk only once per second) or 3 (flush to disk at prepare and at commit, slower and usually redundant). 1 and 3 guarantees that after a crash, committed transactions will not be lost and will be consistent with the binlog and other transactional engines. 2 can get inconsistent and lose transactions if there is a power failure or kernel crash but not if mysqld crashes. 0 has no guarantees in case of crash. 0 and 2 can be faster than 1 or 3.

innodb_flush_method

With which method to flush data

innodb_flush_neighbors

Set to 0 (don't flush neighbors from buffer pool), 1 (flush contiguous neighbors from buffer pool) or 2 (flush neighbors from buffer pool), when flushing a block

innodb_flush_sync

Allow IO bursts at the checkpoints ignoring io_capacity setting

innodb_flushing_avg_loops

Number of iterations over which the background flushing is averaged

innodb_force_load_corrupted

Force InnoDB to load metadata of corrupted table

innodb_force_primary_key

Do not allow creating a table without primary key (off by default)

innodb_force_recovery

Helps to save your data in case the disk image of the database becomes corrupt. Value 5 can return bogus data, and 6 can permanently corrupt data.

innodb_ft_aux_table

FTS internal auxiliary table to be checked

innodb_ft_cache_size

InnoDB Fulltext search cache size in bytes

innodb_ft_enable_diag_print

Whether to enable additional FTS diagnostic printout

innodb_ft_enable_stopword

Create FTS index with stopword

innodb_ft_max_token_size

InnoDB Fulltext search maximum token size in characters

innodb_ft_min_token_size

InnoDB Fulltext search minimum token size in characters

innodb_ft_num_word_optimize

InnoDB Fulltext search number of words to optimize for each optimize table call

innodb_ft_result_cache_limit

InnoDB Fulltext search query result cache limit in bytes

innodb_ft_server_stopword_table

The user supplied stopword table name

innodb_ft_sort_pll_degree

InnoDB Fulltext search parallel sort degree, will round up to nearest power of 2 number

innodb_ft_total_cache_size

Total memory allocated for InnoDB Fulltext Search cache

innodb_ft_user_stopword_table

User supplied stopword table name, effective in the session level

innodb_immediate_scrub_data_uncompressed

Enable scrubbing of data

innodb_instant_alter_column_allowed

File format constraint for ALTER TABLE

innodb_io_capacity

Number of IOPs the server can do. Tunes the background IO rate

innodb_io_capacity_max

Limit to which innodb_io_capacity can be inflated

innodb_large_prefix

Deprecated parameter with no effect

innodb_lock_schedule_algorithm

The algorithm Innodb uses for deciding which locks to grant next when a lock is released. Possible values are FCFS grant the locks in First-Come-First-Served order; VATS use the Variance-Aware-Transaction-Scheduling algorithm, which uses an Eldest-Transaction-First heuristic.

innodb_lock_wait_timeout

Timeout in seconds an InnoDB transaction may wait for a lock before being rolled back. Values above 100000000 disable the timeout.

innodb_log_buffer_size

The size of the buffer which InnoDB uses to write log to the log files on disk

innodb_log_checksums

Deprecated parameter with no effect

innodb_log_compressed_pages

Deprecated parameter with no effect

innodb_log_file_size

Size of each log file in a log group

innodb_log_files_in_group

Deprecated parameter with no effect

innodb_log_group_home_dir

Path to InnoDB log files

innodb_log_optimize_ddl

Deprecated parameter with no effect

innodb_log_write_ahead_size

Redo log write ahead unit size to avoid read-on-write, it should match the OS cache block IO size

innodb_lru_flush_size

How many pages to flush on LRU eviction

innodb_lru_scan_depth

How deep to scan LRU to keep it clean

innodb_max_dirty_pages_pct

Percentage of dirty pages allowed in bufferpool

innodb_max_dirty_pages_pct_lwm

Percentage of dirty pages at which flushing kicks in. The value 0 (default) means 'refer to innodb_max_dirty_pages_pct'.

innodb_max_purge_lag

Desired maximum length of the purge queue (0 = no limit)

innodb_max_purge_lag_delay

Maximum delay of user threads in micro-seconds

innodb_max_purge_lag_wait

Wait until History list length is below the specified limit

innodb_max_undo_log_size

Desired maximum UNDO tablespace size in bytes

innodb_monitor_disable

Turn off a monitor counter

innodb_monitor_enable

Turn on a monitor counter

innodb_monitor_reset

Reset a monitor counter

innodb_monitor_reset_all

Reset all values for a monitor counter

innodb_old_blocks_pct

Percentage of the buffer pool to reserve for 'old' blocks

innodb_old_blocks_time

Move blocks to the 'new' end of the buffer pool if the first access was at least this many milliseconds ago. The timeout is disabled if 0.

innodb_online_alter_log_max_size

Maximum modification log file size for online index creation

innodb_open_files

How many files at the maximum InnoDB keeps open at the same time

innodb_optimize_fulltext_only

Only optimize the Fulltext index of the table

innodb_page_cleaners

Deprecated parameter with no effect

innodb_page_size

Page size to use for all InnoDB tablespaces

innodb_prefix_index_cluster_optimization

Enable prefix optimization to sometimes avoid cluster index lookups

innodb_print_all_deadlocks

Print all deadlocks to MariaDB error log (off by default)

innodb_purge_batch_size

Number of UNDO log pages to purge in one batch from the history list

innodb_purge_rseg_truncate_frequency

Dictates rate at which UNDO records are purged. Value N means purge rollback segment(s) on every Nth iteration of purge invocation

innodb_purge_threads

Number of tasks for purging transaction history

innodb_random_read_ahead

Whether to use read ahead for random access within an extent

innodb_read_ahead_threshold

Number of pages that must be accessed sequentially for InnoDB to trigger a readahead

innodb_read_io_threads

Number of background read I/O threads in InnoDB

innodb_read_only

Start InnoDB in read only mode (off by default)

innodb_replication_delay

Deprecated parameter with no effect

innodb_rollback_on_timeout

Roll back the complete transaction on lock wait timeout, for 4.x compatibility (disabled by default)

innodb_scrub_log

Deprecated parameter with no effect

innodb_scrub_log_speed

Deprecated parameter with no effect

innodb_sort_buffer_size

Memory buffer size for index creation

innodb_spin_wait_delay

Maximum delay between polling for a spin lock (4 by default)

innodb_stats_auto_recalc

InnoDB automatic recalculation of persistent statistics enabled for all tables unless overridden at table level (automatic recalculation is only done when InnoDB decides that the table has changed too much and needs a new statistics)

innodb_stats_include_delete_marked

Include delete marked records when calculating persistent statistics

innodb_stats_method

Specifies how InnoDB index statistics collection code should treat NULLs. Possible values are NULLS_EQUAL (default), NULLS_UNEQUAL and NULLS_IGNORED

innodb_stats_modified_counter

The number of rows modified before we calculate new statistics (default 0 = current limits)

innodb_stats_on_metadata

Enable statistics gathering for metadata commands such as SHOW TABLE STATUS for tables that use transient statistics (off by default)

innodb_stats_persistent

InnoDB persistent statistics enabled for all tables unless overridden at table level

innodb_stats_persistent_sample_pages

The number of leaf index pages to sample when calculating persistent statistics (by ANALYZE, default 20)

innodb_stats_traditional

Enable traditional statistic calculation based on number of configured pages (default true)

innodb_stats_transient_sample_pages

The number of leaf index pages to sample when calculating transient statistics (if persistent statistics are not used, default 8)

innodb_status_output

Enable InnoDB monitor output to the error log

innodb_status_output_locks

Enable InnoDB lock monitor output to the error log. Requires innodb_status_output=ON.

innodb_strict_mode

Use strict mode when evaluating create options

innodb_sync_array_size

Size of the mutex/lock wait array

innodb_sync_spin_loops

Count of spin-loop rounds in InnoDB mutexes (30 by default)

innodb_table_locks

Enable InnoDB locking in LOCK TABLES

innodb_temp_data_file_path

Path to files and their sizes making temp-tablespace

innodb_thread_concurrency

Deprecated parameter with no effect

innodb_thread_sleep_delay

Deprecated parameter with no effect

innodb_tmpdir

Directory for temporary non-tablespace files

innodb_undo_directory

Directory where undo tablespace files live, this path can be absolute

innodb_undo_log_truncate

Enable or Disable Truncate of UNDO tablespace

innodb_undo_logs

Deprecated parameter with no effect

innodb_undo_tablespaces

Number of undo tablespaces to use

innodb_use_atomic_writes

Enable atomic writes, instead of using the doublewrite buffer, for files on devices that supports atomic writes. This option only works on Linux with either FusionIO cards using the directFS filesystem or with Shannon cards using any file system.

innodb_use_native_aio

Use native AIO if supported on this platform

innodb_version

InnoDB version

innodb_write_io_threads

Number of background write I/O threads in InnoDB

insert_id

The value to be used by the following INSERT or ALTER TABLE statement when inserting an AUTO_INCREMENT value

interactive_timeout

The number of seconds the server waits for activity on an interactive connection before closing it

join_buffer_size

The size of the buffer that is used for joins

join_buffer_space_limit

The limit of the space for all join buffers used by a query

join_cache_level

Controls what join operations can be executed with join buffers. Odd numbers are used for plain join buffers while even numbers are used for linked buffers

keep_files_on_create

Don't overwrite stale .MYD and .MYI even if no directory is specified

key_buffer_size

The size in bytes of MyISAM key cache, which is the buffer used for MyISAM index blocks

key_cache_age_threshold

This characterizes the number of hits a hot block has to be untouched until it is considered aged enough to be downgraded to a warm block. This specifies the percentage ratio of that number of hits to the total number of blocks in key cache

key_cache_block_size

The default size of key cache blocks

key_cache_division_limit

The minimum percentage of warm blocks in key cache

key_cache_file_hash_size

Number of hash buckets for open and changed files. If you have a lot of MyISAM files open you should increase this for faster flush of changes. A good value is probably 1/10 of number of possible open MyISAM files.

key_cache_segments

The number of segments in a key cache

large_files_support

Whether mysqld was compiled with options for large file support

large_page_size

Previously showed the size of large memory pages, unused since multiple page size support was added

large_pages

Enable support for large pages

last_gtid

The GTID of the last commit (if binlogging was enabled), or the empty string if none

last_insert_id

The value to be returned from LAST_INSERT_ID()

lc_messages

Set the language used for the error messages

lc_messages_dir

Directory where error messages are

lc_time_names

Set the language used for the month names and the days of the week

license

The type of license the server has

local_infile

Enable LOAD DATA LOCAL INFILE

lock_wait_timeout

Timeout in seconds to wait for a lock before returning an error

locked_in_memory

Whether mysqld was locked in memory with --memlock

log_bin

Whether the binary log is enabled

log_bin_basename

The full path of the binary log file names, excluding the extension

log_bin_compress

Whether the binary log can be compressed

log_bin_compress_min_len

Minimum length of sql statement(in statement mode) or record(in row mode)that can be compressed

log_bin_index

File that holds the names for last binary log files

log_bin_trust_function_creators

If set to FALSE (the default), then when --log-bin is used, creation of a stored function (or trigger) is allowed only to users having the SUPER privilege and only if this stored function (trigger) may not break binary logging. Note that if ALL connections to this server ALWAYS use row-based binary logging, the security issues do not exist and the binary logging cannot break, so you can safely set this to TRUE

log_disabled_statements

Don't log certain types of statements to general log

log_error

Log errors to file (instead of stdout). If file name is not specified then 'datadir'/'log-basename'.err or the 'pid-file' path with extension .err is used

log_output

How logs should be written

log_queries_not_using_indexes

Log queries that are executed without benefit of any index to the slow log if it is open. Same as log_slow_filter='not_using_index'

log_slave_updates

Tells the slave to log the updates from the slave thread to the binary log. You will need to turn it on if you plan to daisy-chain the slaves.

log_slow_admin_statements

Log slow OPTIMIZE, ANALYZE, ALTER and other administrative statements to the slow log if it is open. Resets or sets the option 'admin' in log_slow_disabled_statements

log_slow_disabled_statements

Don't log certain types of statements to slow log

log_slow_filter

Log only certain types of queries to the slow log. If variable empty alll kind of queries are logged. All types are bound by slow_query_time, except 'not_using_index' which is always logged if enabled

log_slow_rate_limit

Write to slow log every #th slow query. Set to 1 to log everything. Increase it to reduce the size of the slow or the performance impact of slow logging

log_slow_slave_statements

Log slow statements executed by slave thread to the slow log if it is open. Resets or sets the option 'slave' in log_slow_disabled_statements

log_slow_verbosity

Verbosity level for the slow log

log_tc_size

Size of transaction coordinator log

log_warnings

Log some non-critical warnings to the error log. Meaningful values are between 0 and 11, where higher values mean more verbosity. Values higher than 11 are equivalent to 11.

long_query_time

Log all queries that have taken more than long_query_time seconds to execute to the slow query log file. The argument will be treated as a decimal value with microsecond precision

low_priority_updates

INSERT/DELETE/UPDATE has lower priority than selects

lower_case_file_system

Case sensitivity of file names on the file system where the data directory is located

lower_case_table_names

Determines whether table names, table aliases, and database names are compared in a case-sensitive manner, and whether tablespace files are stored on disk in a case-sensitive manner

master_verify_checksum

Force checksum verification of logged events in the binary log before sending them to slaves or printing them in the output of SHOW BINLOG EVENTS

max_allowed_packet

Max packet length to send to or receive from the server

max_binlog_cache_size

Sets the total size of the transactional cache

max_binlog_size

Binary log will be rotated automatically when the size exceeds this value

max_binlog_stmt_cache_size

Sets the total size of the statement cache

max_connect_errors

If there is more than this number of interrupted connections from a host this host will be blocked from further connections

max_connections

Maximum number of clients allowed to connect concurrently

max_delayed_threads

Don't start more than this number of threads to handle INSERT DELAYED statements. If set to zero INSERT DELAYED will be not used

max_digest_length

Maximum length considered for digest text

max_error_count

Max number of errors/warnings to store for a statement

max_heap_table_size

Don't allow creation of heap tables bigger than this

max_insert_delayed_threads

Don't start more than this number of threads to handle INSERT DELAYED statements. If set to zero INSERT DELAYED will be not used

max_join_size

Joins that are probably going to read more than max_join_size records return an error

max_length_for_sort_data

Max number of bytes in sorted records

max_password_errors

If there is more than this number of failed connect attempts due to invalid password, user will be blocked from further connections until FLUSH_PRIVILEGES

max_prepared_stmt_count

Maximum number of prepared statements in the server

max_recursive_iterations

Maximum number of iterations when executing recursive queries

max_relay_log_size

relay log will be rotated automatically when the size exceeds this value. If 0 at startup, it's set to max_binlog_size

max_rowid_filter_size

The maximum size of the container of a rowid filter

max_seeks_for_key

Limit assumed max number of seeks when looking up rows based on a key

max_session_mem_used

Amount of memory a single user session is allowed to allocate. This limits the value of the session variable MEM_USED

max_sort_length

The number of bytes to use when sorting BLOB or TEXT values (only the first max_sort_length bytes of each value are used; the rest are ignored)

max_sp_recursion_depth

Maximum stored procedure recursion depth

max_statement_time

A query that has taken more than max_statement_time seconds will be aborted. The argument will be treated as a decimal value with microsecond precision. A value of 0 (default) means no timeout

max_tmp_tables

Unused, will be removed

max_user_connections

The maximum number of active connections for a single user (0 = no limit)

max_write_lock_count

After this many write locks, allow some read locks to run in between

metadata_locks_cache_size

Unused

metadata_locks_hash_instances

Unused

min_examined_row_limit

Don't write queries to slow log that examine fewer rows than that

mrr_buffer_size

Size of buffer to use when using MRR with range access

myisam_block_size

Block size to be used for MyISAM index pages

myisam_data_pointer_size

Default pointer size to be used for MyISAM tables

myisam_max_sort_file_size

Don't use the fast sort index method to created index if the temporary file would get bigger than this

myisam_mmap_size

Restricts the total memory used for memory mapping of MySQL tables

myisam_recover_options

Specifies how corrupted tables should be automatically repaired

myisam_repair_threads

If larger than 1, when repairing a MyISAM table all indexes will be created in parallel, with one thread per index. The value of 1 disables parallel repair

myisam_sort_buffer_size

The buffer that is allocated when sorting the index when doing a REPAIR or when creating indexes with CREATE INDEX or ALTER TABLE

myisam_stats_method

Specifies how MyISAM index statistics collection code should treat NULLs. Possible values of name are NULLS_UNEQUAL (default behavior for 4.1 and later), NULLS_EQUAL (emulate 4.0 behavior), and NULLS_IGNORED

myisam_use_mmap

Use memory mapping for reading and writing MyISAM tables

mysql56_temporal_format

Use MySQL-5.6 (instead of MariaDB-5.3) format for TIME, DATETIME, TIMESTAMP columns

net_buffer_length

Buffer length for TCP/IP and socket communication

net_read_timeout

Number of seconds to wait for more data from a connection before aborting the read

net_retry_count

If a read on a communication port is interrupted, retry this many times before giving up

net_write_timeout

Number of seconds to wait for a block to be written to a connection before aborting the write

old

Use compatible behavior from previous MariaDB version. See also --old-mode

old_alter_table

Alias for alter_algorithm. Deprecated. Use --alter-algorithm instead.

old_mode

Used to emulate old behavior from earlier MariaDB or MySQL versions

old_passwords

Use old password encryption method (needed for 4.0 and older clients)

open_files_limit

If this is not 0, then mysqld will use this value to reserve file descriptors to use with setrlimit(). If this value is 0 or autoset then mysqld will reserve max_connections*5 or max_connections + table_cache*2 (whichever is larger) number of file descriptors

optimizer_max_sel_arg_weight

The maximum weight of the SEL_ARG graph. Set to 0 for no limit

optimizer_prune_level

Controls the heuristic(s) applied during query optimization to prune less-promising partial plans from the optimizer search space. Meaning: 0 - do not apply any heuristic, thus perform exhaustive search; 1 - prune plans based on number of retrieved rows

optimizer_search_depth

Maximum depth of search performed by the query optimizer. Values larger than the number of relations in a query result in better query plans, but take longer to compile a query. Values smaller than the number of tables in a relation result in faster optimization, but may produce very bad query plans. If set to 0, the system will automatically pick a reasonable value.

optimizer_selectivity_sampling_limit

Controls number of record samples to check condition selectivity

optimizer_switch

Fine-tune the optimizer behavior

optimizer_trace

Controls tracing of the Optimizer: optimizer_trace=option=val[,option=val...], where option is one of {enabled} and val is one of {on, off, default}

optimizer_trace_max_mem_size

Maximum allowed size of an optimizer trace

optimizer_use_condition_selectivity

Controls selectivity of which conditions the optimizer takes into account to calculate cardinality of a partial join when it searches for the best execution plan Meaning: 1 - use selectivity of index backed range conditions to calculate the cardinality of a partial join if the last joined table is accessed by full table scan or an index scan, 2 - use selectivity of index backed range conditions to calculate the cardinality of a partial join in any case, 3 - additionally always use selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join, 4 - use histograms to calculate selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join.5 - additionally use selectivity of certain non-range predicates calculated on record samples

pam_debug

Used in debugging builds PAM authentication plugin

pam_use_cleartext_plugin

Use mysql_cleartext_plugin on the client side instead of the dialog plugin. This may be needed for compatibility reasons, but it only supports simple PAM policies that don't require anything besides a password

pam_winbind_workaround

Compare usernames case insensitively to work around pam_winbind unconditional username lowercasing

password_reuse_check_interval

Password history retention period in days (0 means unlimited)

performance_schema

Enable the performance schema

performance_schema_accounts_size

Maximum number of instrumented user@host accounts. Use 0 to disable, -1 for automated sizing.

performance_schema_digests_size

Size of the statement digest. Use 0 to disable, -1 for automated sizing.

performance_schema_events_stages_history_long_size

Number of rows in EVENTS_STAGES_HISTORY_LONG. Use 0 to disable, -1 for automated sizing.

performance_schema_events_stages_history_size

Number of rows per thread in EVENTS_STAGES_HISTORY. Use 0 to disable, -1 for automated sizing.

performance_schema_events_statements_history_long_size

Number of rows in EVENTS_STATEMENTS_HISTORY_LONG. Use 0 to disable, -1 for automated sizing.

performance_schema_events_statements_history_size

Number of rows per thread in EVENTS_STATEMENTS_HISTORY. Use 0 to disable, -1 for automated sizing.

performance_schema_events_transactions_history_long_size

Number of rows in EVENTS_TRANSACTIONS_HISTORY_LONG. Use 0 to disable, -1 for automated sizing.

performance_schema_events_transactions_history_size

Number of rows per thread in EVENTS_TRANSACTIONS_HISTORY. Use 0 to disable, -1 for automated sizing.

performance_schema_events_waits_history_long_size

Number of rows in EVENTS_WAITS_HISTORY_LONG. Use 0 to disable, -1 for automated sizing.

performance_schema_events_waits_history_size

Number of rows per thread in EVENTS_WAITS_HISTORY. Use 0 to disable, -1 for automated sizing.

performance_schema_hosts_size

Maximum number of instrumented hosts. Use 0 to disable, -1 for automated sizing.

performance_schema_max_cond_classes

Maximum number of condition instruments

performance_schema_max_cond_instances

Maximum number of instrumented condition objects. Use 0 to disable, -1 for automated sizing.

performance_schema_max_digest_length

Maximum length considered for digest text, when stored in performance_schema tables

performance_schema_max_file_classes

Maximum number of file instruments

performance_schema_max_file_handles

Maximum number of opened instrumented files

performance_schema_max_file_instances

Maximum number of instrumented files. Use 0 to disable, -1 for automated sizing.

performance_schema_max_index_stat

Maximum number of index statistics for instrumented tables. Use 0 to disable, -1 for automated scaling.

performance_schema_max_memory_classes

Maximum number of memory pool instruments

performance_schema_max_metadata_locks

Maximum number of metadata locks. Use 0 to disable, -1 for automated scaling.

performance_schema_max_mutex_classes

Maximum number of mutex instruments

performance_schema_max_mutex_instances

Maximum number of instrumented MUTEX objects. Use 0 to disable, -1 for automated sizing.

performance_schema_max_prepared_statements_instances

Maximum number of instrumented prepared statements. Use 0 to disable, -1 for automated scaling.

performance_schema_max_program_instances

Maximum number of instrumented programs. Use 0 to disable, -1 for automated scaling.

performance_schema_max_rwlock_classes

Maximum number of rwlock instruments

performance_schema_max_rwlock_instances

Maximum number of instrumented RWLOCK objects. Use 0 to disable, -1 for automated sizing.

performance_schema_max_socket_classes

Maximum number of socket instruments

performance_schema_max_socket_instances

Maximum number of opened instrumented sockets. Use 0 to disable, -1 for automated sizing.

performance_schema_max_sql_text_length

Maximum length of displayed sql text

performance_schema_max_stage_classes

Maximum number of stage instruments

performance_schema_max_statement_classes

Maximum number of statement instruments

performance_schema_max_statement_stack

Number of rows per thread in EVENTS_STATEMENTS_CURRENT

performance_schema_max_table_handles

Maximum number of opened instrumented tables. Use 0 to disable, -1 for automated sizing.

performance_schema_max_table_instances

Maximum number of instrumented tables. Use 0 to disable, -1 for automated sizing.

performance_schema_max_table_lock_stat

Maximum number of lock statistics for instrumented tables. Use 0 to disable, -1 for automated scaling.

performance_schema_max_thread_classes

Maximum number of thread instruments

performance_schema_max_thread_instances

Maximum number of instrumented threads. Use 0 to disable, -1 for automated sizing.

performance_schema_session_connect_attrs_size

Size of session attribute string buffer per thread. Use 0 to disable, -1 for automated sizing.

performance_schema_setup_actors_size

Maximum number of rows in SETUP_ACTORS

performance_schema_setup_objects_size

Maximum number of rows in SETUP_OBJECTS

performance_schema_users_size

Maximum number of instrumented users. Use 0 to disable, -1 for automated sizing.

pid_file

Pid file used by safe_mysqld

plugin_dir

Directory for plugins

plugin_maturity

The lowest desirable plugin maturity. Plugins less mature than that will not be installed or loaded

port

Port number to use for connection or 0 to default to, my.cnf, $MYSQL_TCP_PORT, /etc/services, built-in default (3306), whatever comes first

preload_buffer_size

The size of the buffer that is allocated when preloading indexes

profiling

If set to 1 (0 is default), statement profiling will be enabled. See SHOW PROFILES and SHOW PROFILE.

profiling_history_size

Number of statements about which profiling information is maintained. If set to 0, no profiles are stored. See SHOW PROFILES.

progress_report_time

Seconds between sending progress reports to the client for time-consuming statements. Set to 0 to disable progress reporting.

protocol_version

The version of the client/server protocol used by the MariaDB server

proxy_protocol_networks

Enable proxy protocol for these source networks. The syntax is a comma separated list of IPv4 and IPv6 networks. If the network doesn't contain mask, it is considered to be a single host. "*" represents all networks and must the only directive on the line. String "localhost" represents non-TCP local connections (Unix domain socket, Windows named pipe or shared memory).

proxy_user

The proxy user account name used when logging in

pseudo_slave_mode

SET pseudo_slave_mode= 0,1 are commands that mysqlbinlog adds to beginning and end of binary log dumps. While zero value indeed disables, the actual enabling of the slave applier execution mode is done implicitly when a Format_description_event is sent through the session.

pseudo_thread_id

This variable is for internal server use

query_alloc_block_size

Allocation block size for query parsing and execution

query_cache_limit

Don't cache results that are bigger than this

query_cache_min_res_unit

The minimum size for blocks allocated by the query cache

query_cache_size

The memory allocated to store results from old queries

query_cache_strip_comments

Strip all comments from a query before storing it in the query cache

query_cache_type

OFF = Don't cache or retrieve results. ON = Cache all results except SELECT SQL_NO_CACHE ... queries. DEMAND = Cache only SELECT SQL_CACHE ... queries

query_cache_wlock_invalidate

Invalidate queries in query cache on LOCK for write

query_prealloc_size

Persistent buffer for query parsing and execution

query_response_time_exec_time_debug

Used in debugging builds for tracking query response time execution times

query_response_time_flush

Update of this variable flushes statistics and re-reads query_response_time_range_base

query_response_time_range_base

Select base of log for query_response_time ranges. WARNING: variable change affect only after flush

query_response_time_stats

Enable or disable query response time statisics collecting

rand_seed1

Sets the internal state of the RAND() generator for replication purposes

rand_seed2

Sets the internal state of the RAND() generator for replication purposes

range_alloc_block_size

Allocation block size for storing ranges during optimization

read_binlog_speed_limit

Maximum speed(KB/s) to read binlog from master (0 = no limit)

read_buffer_size

Each thread that does a sequential scan allocates a buffer of this size for each table it scans. If you do many sequential scans, you may want to increase this value

read_only

Make all non-temporary tables read-only, with the exception for replication (slave) threads and users with the SUPER privilege

read_rnd_buffer_size

When reading rows in sorted order after a sort, the rows are read through this buffer to avoid a disk seeks

relay_log

The location and name to use for relay logs

relay_log_basename

The full path of the relay log file names, excluding the extension

relay_log_index

The location and name to use for the file that keeps a list of the last relay logs

relay_log_info_file

The location and name of the file that remembers where the SQL replication thread is in the relay logs

relay_log_purge

if disabled - do not purge relay logs. if enabled - purge them as soon as they are no more needed.

relay_log_recovery

Enables automatic relay log recovery right after the database startup, which means that the IO Thread starts re-fetching from the master right after the last transaction processed

relay_log_space_limit

Maximum space to use for all relay logs

replicate_annotate_row_events

Tells the slave to write annotate rows events received from the master to its own binary log. Ignored if log_slave_updates is not set

replicate_do_db

Tell the slave to restrict replication to updates of tables whose names appear in the comma-separated list. For statement-based replication, only the default database (that is, the one selected by USE) is considered, not any explicitly mentioned tables in the query. For row-based replication, the actual names of table(s) being updated are checked.

replicate_do_table

Tells the slave to restrict replication to tables in the comma-separated list

replicate_events_marked_for_skip

Whether the slave should replicate events that were created with @@skip_replication=1 on the master. Default REPLICATE (no events are skipped). Other values are FILTER_ON_SLAVE (events will be sent by the master but ignored by the slave) and FILTER_ON_MASTER (events marked with @@skip_replication=1 will be filtered on the master and never be sent to the slave).

replicate_ignore_db

Tell the slave to restrict replication to updates of tables whose names do not appear in the comma-separated list. For statement-based replication, only the default database (that is, the one selected by USE) is considered, not any explicitly mentioned tables in the query. For row-based replication, the actual names of table(s) being updated are checked.

replicate_ignore_table

Tells the slave thread not to replicate any statement that updates the specified table, even if any other tables might be updated by the same statement

replicate_wild_do_table

Tells the slave thread to restrict replication to statements where any of the updated tables match the specified database and table name patterns

replicate_wild_ignore_table

Tells the slave thread to not replicate to the tables that match the given wildcard pattern

report_host

Hostname or IP of the slave to be reported to the master during slave registration. Will appear in the output of SHOW SLAVE HOSTS. Leave unset if you do not want the slave to register itself with the master. Note that it is not sufficient for the master to simply read the IP of the slave off the socket once the slave connects. Due to NAT and other routing issues, that IP may not be valid for connecting to the slave from the master or other hosts

report_password

The account password of the slave to be reported to the master during slave registration

report_port

Port for connecting to slave reported to the master during slave registration. Set it only if the slave is listening on a non-default port or if you have a special tunnel from the master or other clients to the slave. If not sure, leave this option unset

report_user

The account user name of the slave to be reported to the master during slave registration

require_secure_transport

When this option is enabled, connections attempted using insecure transport will be rejected. Secure transports are SSL/TLS, Unix sockets or named pipes.

rocksdb_access_hint_on_compaction_start

DBOptions::access_hint_on_compaction_start for RocksDB

rocksdb_advise_random_on_open

DBOptions::advise_random_on_open for RocksDB

rocksdb_allow_concurrent_memtable_write

DBOptions::allow_concurrent_memtable_write for RocksDB

rocksdb_allow_mmap_reads

DBOptions::allow_mmap_reads for RocksDB

rocksdb_allow_mmap_writes

DBOptions::allow_mmap_writes for RocksDB

rocksdb_allow_to_start_after_corruption

Allow server still to start successfully even if RocksDB corruption is detected

rocksdb_blind_delete_primary_key

Deleting rows by primary key lookup, without reading rows (Blind Deletes). Blind delete is disabled if the table has secondary key

rocksdb_block_cache_size

block_cache size for RocksDB

rocksdb_block_restart_interval

BlockBasedTableOptions::block_restart_interval for RocksDB

rocksdb_block_size

BlockBasedTableOptions::block_size for RocksDB

rocksdb_block_size_deviation

BlockBasedTableOptions::block_size_deviation for RocksDB

rocksdb_bulk_load

Use bulk-load mode for inserts. This disables unique_checks and enables rocksdb_commit_in_the_middle.

rocksdb_bulk_load_allow_sk

Allow bulk loading of sk keys during bulk-load. Can be changed only when bulk load is disabled.

rocksdb_bulk_load_allow_unsorted

Allow unsorted input during bulk-load. Can be changed only when bulk load is disabled.

rocksdb_bulk_load_size

Max #records in a batch for bulk-load mode

rocksdb_bytes_per_sync

DBOptions::bytes_per_sync for RocksDB

rocksdb_cache_dump

Include RocksDB block cache content in core dump

rocksdb_cache_high_pri_pool_ratio

Specify the size of block cache high-pri pool

rocksdb_cache_index_and_filter_blocks

BlockBasedTableOptions::cache_index_and_filter_blocks for RocksDB

rocksdb_cache_index_and_filter_with_high_priority

cache_index_and_filter_blocks_with_high_priority for RocksDB

rocksdb_checksums_pct

How many percentages of rows to be checksummed

rocksdb_collect_sst_properties

Enables collecting SST file properties on each flush

rocksdb_commit_in_the_middle

Commit rows implicitly every rocksdb_bulk_load_size, on bulk load/insert, update and delete

rocksdb_commit_time_batch_for_recovery

TransactionOptions::commit_time_batch_for_recovery for RocksDB

rocksdb_compact_cf

Compact column family

rocksdb_compaction_readahead_size

DBOptions::compaction_readahead_size for RocksDB

rocksdb_compaction_sequential_deletes

RocksDB will trigger compaction for the file if it has more than this number sequential deletes per window

rocksdb_compaction_sequential_deletes_count_sd

Counting SingleDelete as rocksdb_compaction_sequential_deletes

rocksdb_compaction_sequential_deletes_file_size

Minimum file size required for compaction_sequential_deletes

rocksdb_compaction_sequential_deletes_window

Size of the window for counting rocksdb_compaction_sequential_deletes

rocksdb_create_checkpoint

Checkpoint directory

rocksdb_create_if_missing

DBOptions::create_if_missing for RocksDB

rocksdb_create_missing_column_families

DBOptions::create_missing_column_families for RocksDB

rocksdb_datadir

RocksDB data directory

rocksdb_db_write_buffer_size

DBOptions::db_write_buffer_size for RocksDB

rocksdb_deadlock_detect

Enables deadlock detection

rocksdb_deadlock_detect_depth

Number of transactions deadlock detection will traverse through before assuming deadlock

rocksdb_debug_manual_compaction_delay

For debugging purposes only. Sleeping specified seconds for simulating long running compactions.

rocksdb_debug_optimizer_no_zero_cardinality

In case if cardinality is zero, overrides it with some value

rocksdb_debug_ttl_ignore_pk

For debugging purposes only. If true, compaction filtering will not occur on PK TTL data. This variable is a no-op in non-debug builds.

rocksdb_debug_ttl_read_filter_ts

For debugging purposes only. Overrides the TTL read filtering time to time + debug_ttl_read_filter_ts. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

rocksdb_debug_ttl_rec_ts

For debugging purposes only. Overrides the TTL of records to now() + debug_ttl_rec_ts. The value can be +/- to simulate a record inserted in the past vs a record inserted in the 'future'. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

rocksdb_debug_ttl_snapshot_ts

For debugging purposes only. Sets the snapshot during compaction to now() + debug_set_ttl_snapshot_ts. The value can be +/- to simulate a snapshot in the past vs a snapshot created in the 'future'. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

rocksdb_default_cf_options

default cf options for RocksDB

rocksdb_delayed_write_rate

DBOptions::delayed_write_rate

rocksdb_delete_cf

Delete column family

rocksdb_delete_obsolete_files_period_micros

DBOptions::delete_obsolete_files_period_micros for RocksDB

rocksdb_enable_2pc

Enable two phase commit for MyRocks

rocksdb_enable_bulk_load_api

Enables using SstFileWriter for bulk loading

rocksdb_enable_insert_with_update_caching

Whether to enable optimization where we cache the read from a failed insertion attempt in INSERT ON DUPLICATE KEY UPDATE

rocksdb_enable_thread_tracking

DBOptions::enable_thread_tracking for RocksDB

rocksdb_enable_ttl

Enable expired TTL records to be dropped during compaction

rocksdb_enable_ttl_read_filtering

For tables with TTL, expired records are skipped/filtered out during processing and in query results. Disabling this will allow these records to be seen, but as a result rows may disappear in the middle of transactions as they are dropped during compaction. Use with caution.

rocksdb_enable_write_thread_adaptive_yield

DBOptions::enable_write_thread_adaptive_yield for RocksDB

rocksdb_error_if_exists

DBOptions::error_if_exists for RocksDB

rocksdb_error_on_suboptimal_collation

Raise an error instead of warning if a sub-optimal collation is used

rocksdb_flush_log_at_trx_commit

Sync on transaction commit. Similar to innodb_flush_log_at_trx_commit. 1: sync on commit, 0,2: not sync on commit

rocksdb_force_compute_memtable_stats

Force to always compute memtable stats

rocksdb_force_compute_memtable_stats_cachetime

Time in usecs to cache memtable estimates

rocksdb_force_flush_memtable_and_lzero_now

Acts similar to force_flush_memtable_now, but also compacts all L0 files

rocksdb_force_flush_memtable_now

Forces memstore flush which may block all write requests so be careful

rocksdb_force_index_records_in_range

Used to override the result of records_in_range() when FORCE INDEX is used

rocksdb_git_hash

Git revision of the RocksDB library used by MyRocks

rocksdb_hash_index_allow_collision

BlockBasedTableOptions::hash_index_allow_collision for RocksDB

rocksdb_ignore_datadic_errors

Ignore MyRocks' data directory errors. (CAUTION: Use only to start the server and perform repairs. Do NOT use for regular operation)

rocksdb_ignore_unknown_options

Enable ignoring unknown options passed to RocksDB

rocksdb_index_type

BlockBasedTableOptions::index_type for RocksDB

rocksdb_info_log_level

Filter level for info logs to be written mysqld error log. Valid values include 'debug_level', 'info_level', 'warn_level''error_level' and 'fatal_level'.

rocksdb_io_write_timeout

Timeout for experimental I/O watchdog

rocksdb_is_fd_close_on_exec

DBOptions::is_fd_close_on_exec for RocksDB

rocksdb_keep_log_file_num

DBOptions::keep_log_file_num for RocksDB

rocksdb_large_prefix

Support large index prefix length of 3072 bytes. If off, the maximum index prefix length is 767.

rocksdb_lock_scanned_rows

Take and hold locks on rows that are scanned but not updated

rocksdb_lock_wait_timeout

Number of seconds to wait for lock

rocksdb_log_file_time_to_roll

DBOptions::log_file_time_to_roll for RocksDB

rocksdb_manifest_preallocation_size

DBOptions::manifest_preallocation_size for RocksDB

rocksdb_manual_compaction_threads

How many rocksdb threads to run for manual compactions

rocksdb_manual_wal_flush

DBOptions::manual_wal_flush for RocksDB

rocksdb_master_skip_tx_api

Skipping holding any lock on row access. Not effective on slave.

rocksdb_max_background_jobs

DBOptions::max_background_jobs for RocksDB

rocksdb_max_latest_deadlocks

Maximum number of recent deadlocks to store

rocksdb_max_log_file_size

DBOptions::max_log_file_size for RocksDB

rocksdb_max_manifest_file_size

DBOptions::max_manifest_file_size for RocksDB

rocksdb_max_manual_compactions

Maximum number of pending + ongoing number of manual compactions

rocksdb_max_open_files

DBOptions::max_open_files for RocksDB

rocksdb_max_row_locks

Maximum number of locks a transaction can have

rocksdb_max_subcompactions

DBOptions::max_subcompactions for RocksDB

rocksdb_max_total_wal_size

DBOptions::max_total_wal_size for RocksDB

rocksdb_merge_buf_size

Size to allocate for merge sort buffers written out to disk during inplace index creation

rocksdb_merge_combine_read_size

Size that we have to work with during combine (reading from disk) phase of external sort during fast index creation

rocksdb_merge_tmp_file_removal_delay_ms

Fast index creation creates a large tmp file on disk during index creation. Removing this large file all at once when index creation is complete can cause trim stalls on Flash. This variable specifies a duration to sleep (in milliseconds) between calling chsize() to truncate the file in chunks. The chunk size is the same as merge_buf_size.

rocksdb_new_table_reader_for_compaction_inputs

DBOptions::new_table_reader_for_compaction_inputs for RocksDB

rocksdb_no_block_cache

BlockBasedTableOptions::no_block_cache for RocksDB

rocksdb_override_cf_options

option overrides per cf for RocksDB

rocksdb_paranoid_checks

DBOptions::paranoid_checks for RocksDB

rocksdb_pause_background_work

Disable all rocksdb background operations

rocksdb_perf_context_level

Perf Context Level for rocksdb internal timer stat collection

rocksdb_persistent_cache_path

Path for BlockBasedTableOptions::persistent_cache for RocksDB

rocksdb_persistent_cache_size_mb

Size of cache in MB for BlockBasedTableOptions::persistent_cache for RocksDB

rocksdb_pin_l0_filter_and_index_blocks_in_cache

pin_l0_filter_and_index_blocks_in_cache for RocksDB

rocksdb_print_snapshot_conflict_queries

Logging queries that got snapshot conflict errors into *.err log

rocksdb_rate_limiter_bytes_per_sec

DBOptions::rate_limiter bytes_per_sec for RocksDB

rocksdb_records_in_range

Used to override the result of records_in_range(). Set to a positive number to override

rocksdb_remove_mariabackup_checkpoint

Remove mariabackup checkpoint

rocksdb_reset_stats

Reset the RocksDB internal statistics without restarting the DB

rocksdb_rollback_on_timeout

Whether to roll back the complete transaction or a single statement on lock wait timeout (a single statement by default)

rocksdb_seconds_between_stat_computes

Sets a number of seconds to wait between optimizer stats recomputation. Only changed indexes will be refreshed.

rocksdb_signal_drop_index_thread

Wake up drop index thread

rocksdb_sim_cache_size

Simulated cache size for RocksDB

rocksdb_skip_bloom_filter_on_read

Skip using bloom filter for reads

rocksdb_skip_fill_cache

Skip filling block cache on read requests

rocksdb_skip_unique_check_tables

Skip unique constraint checking for the specified tables

rocksdb_sst_mgr_rate_bytes_per_sec

DBOptions::sst_file_manager rate_bytes_per_sec for RocksDB

rocksdb_stats_dump_period_sec

DBOptions::stats_dump_period_sec for RocksDB

rocksdb_stats_level

Statistics Level for RocksDB. Default is 0 (kExceptHistogramOrTimers)

rocksdb_stats_recalc_rate

The number of indexes per second to recalculate statistics for. 0 to disable background recalculation.

rocksdb_store_row_debug_checksums

Include checksums when writing index/table records

rocksdb_strict_collation_check

Enforce case sensitive collation for MyRocks indexes

rocksdb_strict_collation_exceptions

List of tables (using regex) that are excluded from the case sensitive collation enforcement

rocksdb_supported_compression_types

Compression algorithms supported by RocksDB

rocksdb_table_cache_numshardbits

DBOptions::table_cache_numshardbits for RocksDB

rocksdb_table_stats_sampling_pct

Percentage of entries to sample when collecting statistics about table properties. Specify either 0 to sample everything or percentage [1..100]. By default 10% of entries are sampled.

rocksdb_tmpdir

Directory for temporary files during DDL operations

rocksdb_trace_sst_api

Generate trace output in the log for each call to the SstFileWriter

rocksdb_two_write_queues

DBOptions::two_write_queues for RocksDB

rocksdb_unsafe_for_binlog

Allowing statement based binary logging which may break consistency

rocksdb_update_cf_options

Option updates per column family for RocksDB

rocksdb_use_adaptive_mutex

DBOptions::use_adaptive_mutex for RocksDB

rocksdb_use_clock_cache

Use ClockCache instead of default LRUCache for RocksDB

rocksdb_use_direct_io_for_flush_and_compaction

DBOptions::use_direct_io_for_flush_and_compaction for RocksDB

rocksdb_use_direct_reads

DBOptions::use_direct_reads for RocksDB

rocksdb_use_fsync

DBOptions::use_fsync for RocksDB

rocksdb_validate_tables

Verify all .frm files match all RocksDB tables (0 means no verification, 1 means verify and fail on error, and 2 means verify but continue

rocksdb_verify_row_debug_checksums

Verify checksums when reading index/table records

rocksdb_wal_bytes_per_sync

DBOptions::wal_bytes_per_sync for RocksDB

rocksdb_wal_dir

DBOptions::wal_dir for RocksDB

rocksdb_wal_recovery_mode

DBOptions::wal_recovery_mode for RocksDB. Default is kAbsoluteConsistency

rocksdb_wal_size_limit_mb

DBOptions::WAL_size_limit_MB for RocksDB

rocksdb_wal_ttl_seconds

DBOptions::WAL_ttl_seconds for RocksDB

rocksdb_whole_key_filtering

BlockBasedTableOptions::whole_key_filtering for RocksDB

rocksdb_write_batch_max_bytes

Maximum size of write batch in bytes. 0 means no limit.

rocksdb_write_disable_wal

WriteOptions::disableWAL for RocksDB

rocksdb_write_ignore_missing_column_families

WriteOptions::ignore_missing_column_families for RocksDB

rocksdb_write_policy

DBOptions::write_policy for RocksDB

rowid_merge_buff_size

The size of the buffers used [NOT] IN evaluation via partial matching

rpl_semi_sync_master_enabled

Enable semi-synchronous replication master (disabled by default)

rpl_semi_sync_master_timeout

The timeout value (in ms) for semi-synchronous replication in the master

rpl_semi_sync_master_trace_level

The tracing level for semi-sync replication

rpl_semi_sync_master_wait_no_slave

Wait until timeout when no semi-synchronous replication slave available (enabled by default)

rpl_semi_sync_master_wait_point

Should transaction wait for semi-sync ack after having synced binlog, or after having committed in storage engine

rpl_semi_sync_slave_delay_master

Only write master info file when ack is needed

rpl_semi_sync_slave_enabled

Enable semi-synchronous replication slave (disabled by default)

rpl_semi_sync_slave_kill_conn_timeout

Timeout for the mysql connection used to kill the slave io_thread's connection on master. This timeout comes into play when stop slave is executed.

rpl_semi_sync_slave_trace_level

The tracing level for semi-sync replication

s3_access_key

AWS access key

s3_block_size

Block size for S3

s3_bucket

AWS bucket

s3_debug

Generates trace file from libmarias3 on stderr for debugging

s3_host_name

AWS host name

s3_pagecache_age_threshold

This characterizes the number of hits a hot block has to be untouched until it is considered aged enough to be downgraded to a warm block. This specifies the percentage ratio of that number of hits to the total number of blocks in the page cache.

s3_pagecache_buffer_size

The size of the buffer used for index blocks for S3 tables. Increase this to get better index handling (for all reads and multiple writes) to as much as you can afford.

s3_pagecache_division_limit

The minimum percentage of warm blocks in key cache

s3_pagecache_file_hash_size

Number of hash buckets for open files. If you have a lot of S3 files open you should increase this for faster flush of changes. A good value is probably 1/10 of number of possible open S3 files.

s3_port

Port number to connect to (0 means use default)

s3_protocol_version

Protocol used to communication with S3. One of "Auto", "Amazon" or "Original".

s3_region

AWS region

s3_replicate_alter_as_create_select

When converting S3 table to local table, log all rows in binary log

s3_secret_key

AWS secret key

s3_slave_ignore_updates

If the slave has shares same S3 storage as the master

s3_use_http

If true, force use of HTTP protocol

secure_auth

Disallow authentication for accounts that have old (pre-4.1) passwords

secure_file_priv

Limit LOAD DATA, SELECT ... OUTFILE, and LOAD_FILE() to files within specified directory

secure_timestamp

Restricts direct setting of a session timestamp. Possible levels are: YES - timestamp cannot deviate from the system clock, REPLICATION - replication thread can adjust timestamp to match the master's, SUPER - a user with this privilege and a replication thread can adjust timestamp, NO - historical behavior, anyone can modify session timestamp

server_audit_file_path

Path to the log file

server_audit_file_rotate_now

Force log rotation now

server_audit_file_rotate_size

Maximum size of the log to start the rotation

server_audit_file_rotations

Number of rotations before log is removed

server_audit_load_on_error

Do not load the plugin if filter definitions are invalid

server_audit_logging

Turn on/off the logging

server_audit_mode

Auditing mode

server_audit_output_type

Desired output type. Possible values - 'syslog', 'file' or 'null' as no output.

server_audit_query_log_limit

Limit on the length of the query string in a record

server_audit_reload_filters

Reload filter definitions from tables

server_audit_syslog_facility

The 'facility' parameter of the SYSLOG record. The default is LOG_USER.

server_audit_syslog_ident

The SYSLOG identifier - the beginning of each SYSLOG record

server_audit_syslog_info

The <info> string to be added to the SYSLOG record

server_audit_syslog_priority

The 'priority' parameter of the SYSLOG record. The default is LOG_INFO.

server_id

Uniquely identifies the server instance in the community of replication partners

session_track_schema

Track changes to the default schema

session_track_state_change

Track changes to the session state

session_track_system_variables

Track changes in registered system variables

session_track_transaction_info

Track changes to the transaction attributes. OFF to disable; STATE to track just transaction state (Is there an active transaction? Does it have any data? etc.); CHARACTERISTICS to track transaction state and report all statements needed to start a transaction with the same characteristics (isolation level, read only/read write,snapshot - but not any work done / data modified within the transaction).

shared_memory

Enables use of shared memory for Servers running on Microsoft Windows

shared_memory_base_name

Base name for shared memory usage by Server running on Microsoft Windows

shutdown_wait_for_slaves

when ON, SHUTDOWN command runs with implicit WAIT FOR ALL SLAVES option

simple_password_check_digits

Minimal required number of digits

simple_password_check_letters_same_case

Minimal required number of letters of the same letter case.This limit is applied separately to upper-case and lower-case letters

simple_password_check_minimal_length

Minimal required password length

simple_password_check_other_characters

Minimal required number of other (not letters or digits) characters

skip_external_locking

Don't use system (external) locking

skip_name_resolve

Don't resolve hostnames. All hostnames are IP's or 'localhost'.

skip_networking

Don't allow connection with TCP/IP

skip_parallel_replication

If set when a transaction is written to the binlog, parallel apply of that transaction will be avoided on a slave where slave_parallel_mode is not "aggressive". Can be used to avoid unnecessary rollback and retry for transactions that are likely to cause a conflict if replicated in parallel.

skip_replication

Changes are logged into the binary log with the @@skip_replication flag set. Such events will not be replicated by slaves that run with --replicate-events-marked-for-skip set different from its default of REPLICATE. See Selectively skipping replication of binlog events for more information.

skip_show_database

Don't allow 'SHOW DATABASE' commands

slave_compressed_protocol

Use compression on master/slave protocol

slave_ddl_exec_mode

How replication events should be executed. Legal values are STRICT and IDEMPOTENT (default). In IDEMPOTENT mode, replication will not stop for DDL operations that are idempotent. This means that CREATE TABLE is treated as CREATE TABLE OR REPLACE and DROP TABLE is treated as DROP TABLE IF EXISTS.

slave_domain_parallel_threads

Maximum number of parallel threads to use on slave for events in a single replication domain. When using multiple domains, this can be used to limit a single domain from grabbing all threads and thus stalling other domains. The default of 0 means to allow a domain to grab as many threads as it wants, up to the value of slave_parallel_threads.

slave_exec_mode

How replication events should be executed. Legal values are STRICT (default) and IDEMPOTENT. In IDEMPOTENT mode, replication will not stop for operations that are idempotent. For example, in row based replication attempts to delete rows that doesn't exist will be ignored. In STRICT mode, replication will stop on any unexpected difference between the master and the slave.

slave_load_tmpdir

The location where the slave should put its temporary files when replicating a LOAD DATA INFILE command

slave_max_allowed_packet

The maximum packet length to sent successfully from the master to slave

slave_max_statement_time

A query that has taken more than slave_max_statement_time seconds to run on the slave will be aborted. The argument will be treated as a decimal value with microsecond precision. A value of 0 (default) means no timeout

slave_net_timeout

Number of seconds to wait for more data from any master/slave connection before aborting the read

slave_parallel_max_queued

Limit on how much memory SQL threads should use per parallel replication thread when reading ahead in the relay log looking for opportunities for parallel replication. Only used when --slave-parallel-threads > 0.

slave_parallel_mode

Controls what transactions are applied in parallel when using --slave-parallel-threads. Possible values: "optimistic" tries to apply most transactional DML in parallel, and handles any conflicts with rollback and retry. "conservative" limits parallelism in an effort to avoid any conflicts. "aggressive" tries to maximise the parallelism, possibly at the cost of increased conflict rate. "minimal" only parallelizes the commit steps of transactions. "none" disables parallel apply completely.

slave_parallel_threads

If non-zero, number of threads to spawn to apply in parallel events on the slave that were group-committed on the master or were logged with GTID in different replication domains. Note that these threads are in addition to the IO and SQL threads, which are always created by a replication slave

slave_parallel_workers

Alias for slave_parallel_threads

slave_run_triggers_for_rbr

Modes for how triggers in row-base replication on slave side will be executed. Legal values are NO (default), YES, LOGGING and ENFORCE. NO means that trigger for RBR will not be running on slave. YES and LOGGING means that triggers will be running on slave, if there was not triggers running on the master for the statement. LOGGING also means results of that the executed triggers work will be written to the binlog. ENFORCE means that triggers will always be run on the slave, even if there are triggers on the master. ENFORCE implies LOGGING.

slave_skip_errors

Tells the slave thread to continue replication when a query event returns an error from the provided list

slave_sql_verify_checksum

Force checksum verification of replication events after reading them from relay log. Note: Events are always checksum-verified by slave on receiving them from the network before writing them to the relay log

slave_transaction_retries

Number of times the slave SQL thread will retry a transaction in case it failed with a deadlock, elapsed lock wait timeout or listed in slave_transaction_retry_errors, before giving up and stopping

slave_transaction_retry_errors

Tells the slave thread to retry transaction for replication when a query event returns an error from the provided list. Deadlock error, elapsed lock wait timeout, net read error, net read timeout, net write error, net write timeout, connect error and 2 types of lost connection error are automatically added to this list

slave_transaction_retry_interval

Interval of the slave SQL thread will retry a transaction in case it failed with a deadlock or elapsed lock wait timeout or listed in slave_transaction_retry_errors

slave_type_conversions

Configures how data type conversions are handled when row-based binary log events are applied. When set to the empty string, data types must match exactly, and no conversions are allowed.

slow_launch_time

If creating the thread takes longer than this value (in seconds), the Slow_launch_threads counter will be incremented

slow_query_log

Log slow queries to a table or log file. Defaults logging to a file 'hostname'-slow.log or a table mysql.slow_log if --log-output=TABLE is used. Must be enabled to activate other slow log options.

slow_query_log_file

Log slow queries to given log file. Defaults logging to 'hostname'-slow.log. Must be enabled to activate other slow log options

socket

Socket file to use for connection

sort_buffer_size

Each thread that needs to do a sort allocates a buffer of this size

spider_auto_increment_mode

Mode of auto increment

spider_bgs_first_read

Number of first read records when background search is used

spider_bgs_mode

Mode of background search

spider_bgs_second_read

Number of second read records when background search is used

spider_bka_engine

Temporary table's engine for BKA

spider_bka_mode

Mode of BKA for Spider

spider_bka_table_name_type

The type of temporary table name for bka

spider_block_size

Index block size

spider_buffer_size

Buffer size

spider_bulk_size

Bulk insert size

spider_bulk_update_mode

The mode of bulk updating and deleting

spider_bulk_update_size

Bulk update size

spider_casual_read

Read casually if it is possible

spider_conn_recycle_mode

Connection recycle mode

spider_conn_recycle_strict

Strict connection recycle

spider_conn_wait_timeout

the values, as the max waiting time when spider get a remote conn

spider_connect_error_interval

Return same error code until interval passes if connection is failed

spider_connect_mutex

Use mutex at connecting

spider_connect_retry_count

Connect retry count

spider_connect_retry_interval

Connect retry interval

spider_connect_timeout

Wait timeout of connecting to remote server

spider_crd_bg_mode

Mode of cardinality confirmation at background

spider_crd_interval

Interval of cardinality confirmation.(second)

spider_crd_mode

Mode of cardinality confirmation

spider_crd_sync

Cardinality synchronization in partitioned table

spider_crd_type

Type of cardinality calculation

spider_crd_weight

Weight coefficient to calculate effectiveness of index from cardinality of column

spider_delete_all_rows_type

The type of delete_all_rows

spider_direct_aggregate

Pushdown aggregation functions if possible

spider_direct_dup_insert

Execute "REPLACE" and "INSERT IGNORE" on remote server and avoid duplicate check on local server

spider_direct_order_limit

Send 'ORDER BY' and 'LIMIT' to remote server directly

spider_dry_access

dry access

spider_error_read_mode

Read error mode if error

spider_error_write_mode

Write error mode if error

spider_first_read

Number of first read records

spider_force_commit

Force prepare, commit, rollback mode

spider_general_log

Log query to remote server in general log

spider_index_hint_pushdown

switch to control if push down index hint, like force_index

spider_init_sql_alloc_size

Initial sql string alloc size

spider_internal_limit

Internal limit

spider_internal_offset

Internal offset

spider_internal_optimize

Execute optimize to remote server

spider_internal_optimize_local

Execute optimize to remote server with local

spider_internal_sql_log_off

Manage SQL_LOG_OFF mode statement to the data nodes

spider_internal_unlock

Unlock tables for using connections in sql

spider_internal_xa

Use inner xa transaction

spider_internal_xa_id_type

The type of internal_xa id

spider_internal_xa_snapshot

Action of inner xa and snapshot both using

spider_load_crd_at_startup

Load crd from system table at startup

spider_load_sts_at_startup

Load sts from system table at startup

spider_local_lock_table

Remote server transmission when lock tables is executed at local

spider_lock_exchange

Exchange select lock to lock tables

spider_log_result_error_with_sql

Log sql at logging result errors

spider_log_result_errors

Log error from remote server in error log

spider_low_mem_read

Use low memory mode when SQL(SELECT) internally issued to a remote server is executed and get a result list

spider_max_connections

the values, as the max conncetion from spider to remote mysql. Default 0, mean unlimit the connections

spider_max_order

Max columns for order by

spider_multi_split_read

Sprit read mode for multi range

spider_net_read_timeout

Wait timeout of receiving data from remote server

spider_net_write_timeout

Wait timeout of sending data to remote server

spider_ping_interval_at_trx_start

Ping interval at transaction start

spider_quick_mode

The retrieval result from a remote server is acquired by acquisition one by one

spider_quick_page_byte

The limitation of memory size in a page when acquisition one by one

spider_quick_page_size

Number of records in a page when acquisition one by one

spider_read_only_mode

Read only

spider_remote_access_charset

Set remote access charset at connecting for improvement performance of connection if you know

spider_remote_autocommit

Set autocommit mode at connecting for improvement performance of connection if you know

spider_remote_default_database

Set remote database at connecting for improvement performance of connection if you know

spider_remote_sql_log_off

Set SQL_LOG_OFF mode on connecting for improved performance of connection, if you know

spider_remote_time_zone

Set remote time_zone at connecting for improvement performance of connection if you know

spider_remote_trx_isolation

Set transaction isolation level at connecting for improvement performance of connection if you know

spider_remote_wait_timeout

Wait timeout on remote server

spider_reset_sql_alloc

Reset sql string alloc after execute

spider_same_server_link

Permit one to link same server's table

spider_second_read

Number of second read records

spider_select_column_mode

The mode of using columns at select clause

spider_selupd_lock_mode

Lock for select with update

spider_semi_split_read

Use offset and limit parameter in SQL for split_read parameter

spider_semi_split_read_limit

The limit value for semi_split_read

spider_semi_table_lock

Table lock during execute a sql

spider_semi_table_lock_connection

Use different connection if semi_table_lock is enabled

spider_semi_trx

Take a transaction during execute a sql

spider_semi_trx_isolation

Transaction isolation level during execute a sql

spider_skip_default_condition

Skip generating internal default condition

spider_skip_parallel_search

Skip parallel search by specific conditions

spider_slave_trx_isolation

Transaction isolation level when Spider table is used by slave SQL thread

spider_split_read

Number of rows at a select

spider_store_last_crd

Store last crd result into system table

spider_store_last_sts

Store last sts result into system table

spider_strict_group_by

Use columns in select clause strictly for group by clause

spider_sts_bg_mode

Mode of table state confirmation at background

spider_sts_interval

Interval of table state confirmation.(second)

spider_sts_mode

Mode of table state confirmation

spider_sts_sync

Table state synchronization in partitioned table

spider_support_xa

XA support

spider_sync_autocommit

Sync autocommit

spider_sync_sql_mode

Sync sql_mode

spider_sync_trx_isolation

Sync transaction isolation level

spider_table_crd_thread_count

Static thread count of table crd

spider_table_init_error_interval

Return same error code until interval passes if table init is failed

spider_table_sts_thread_count

Static thread count of table sts

spider_udf_ct_bulk_insert_interval

The interval time between bulk insert and next bulk insert at coping

spider_udf_ct_bulk_insert_rows

The number of rows inserted with bulk insert of one time at coping

spider_udf_ds_bulk_insert_rows

Number of rows for bulk inserting

spider_udf_ds_table_loop_mode

Table loop mode if the number of tables in table list are less than the number of result sets

spider_udf_ds_use_real_table

Use real table for temporary table list

spider_udf_table_lock_mutex_count

Mutex count of table lock for Spider UDFs

spider_udf_table_mon_mutex_count

Mutex count of table mon for Spider UDFs

spider_use_all_conns_snapshot

When start trx with snapshot, it send to all connections

spider_use_cond_other_than_pk_for_update

Use all conditions even if condition has pk

spider_use_consistent_snapshot

Use start transaction with consistent snapshot

spider_use_default_database

Use default database

spider_use_flash_logs

Execute flush logs to remote server

spider_use_handler

Use handler for reading

spider_use_pushdown_udf

Remote server transmission existence when UDF is used at condition and "engine_condition_pushdown=1"

spider_use_snapshot_with_flush_tables

Execute optimize to remote server with local

spider_use_table_charset

Use table charset for remote access

spider_version

The version of Spider

spider_wait_timeout

Wait timeout of setting to remote server

spider_xa_register_mode

Mode of XA transaction register into system table

sql_auto_is_null

If set to 1, the query SELECT * FROM table_name WHERE auto_increment_column IS NULL will return an auto-increment that has just been successfully inserted, the same as the LAST_INSERT_ID() function. Some ODBC programs make use of this IS NULL comparison.

sql_big_selects

If set to 0, MariaDB will not perform large SELECTs. See max_join_size for details. If max_join_size is set to anything but DEFAULT, sql_big_selects is automatically set to 0. If sql_big_selects is again set, max_join_size will be ignored.

sql_buffer_result

If set to 1 (0 is default), results from SELECT statements are always placed into temporary tables. This can help the server when it takes a long time to send the results to the client by allowing the table locks to be freed early.

sql_if_exists

If set to 1 adds an implicate IF EXISTS to ALTER, RENAME and DROP of TABLES, VIEWS, FUNCTIONS and PACKAGES

sql_log_bin

Controls if the client's queries are logged to the binary log for replication. READ-ONLY.

sql_log_off

Controls if the client's queries are left out of the general query log. READ-ONLY.

sql_mode

Overrides the default behavior of the server in several contexts

sql_notes

If set to 1, the default, warning_count is incremented each time a Note warning is encountered. If set to 0, Note warnings are not recorded. mysqldump has outputs to set this variable to 0 so that no unnecessary increments occur when data is reloaded.

sql_quote_show_create

If set to 1, the default, the server will quote identifiers for SHOW CREATE DATABASE, SHOW CREATE TABLE and SHOW CREATE VIEW statements. Quoting is disabled if set to 0. Enable to ensure replications works when identifiers require quoting.

sql_safe_updates

If set to 1, UPDATEs and DELETEs need either a key in the WHERE clause, or a LIMIT clause, or else they will aborted. Prevents the common mistake of accidentally deleting or updating every row in a table.

sql_select_limit

The maximum number of rows to return from SELECT statements

sql_slave_skip_counter

Skip the next N events from the master log

sql_warnings

If set to 1, single-row INSERTs will produce a string containing warning information if a warning occurs

ssl_ca

CA file in PEM format (check OpenSSL docs, implies --ssl)

ssl_capath

CA directory (check OpenSSL docs, implies --ssl)

ssl_cert

X509 cert in PEM format (implies --ssl)

ssl_cipher

SSL cipher to use (implies --ssl)

ssl_crl

CRL file in PEM format (check OpenSSL docs, implies --ssl)

ssl_crlpath

CRL directory (check OpenSSL docs, implies --ssl)

ssl_key

X509 key in PEM format (implies --ssl)

standard_compliant_cte

Allow only CTEs compliant to SQL standard

storage_engine

Alias for @@default_storage_engine. Deprecated

stored_program_cache

The soft upper limit for number of cached stored routines for one connection

strict_password_validation

When password validation plugins are enabled, reject passwords that cannot be validated (passwords specified as a hash)

sync_binlog

Synchronously flush binary log to disk after every #th event. Use 0 (default) to disable synchronous flushing

sync_frm

Sync .frm files to disk on creation

sync_master_info

Synchronously flush master info to disk after every #th event. Use 0 to disable synchronous flushing

sync_relay_log

Synchronously flush relay log to disk after every #th event. Use 0 to disable synchronous flushing

sync_relay_log_info

Synchronously flush relay log info to disk after every #th transaction. Use 0 to disable synchronous flushing

system_time_zone

Sets the server's system time zone. SkySQL interfaces refer to this system variable as default_time_zone.

system_versioning_alter_history

Versioning ALTER TABLE mode. ERROR: Fail ALTER with error; KEEP: Keep historical system rows and subject them to ALTER

system_versioning_asof

Default value for the FOR SYSTEM_TIME AS OF clause

table_definition_cache

The number of cached table definitions

table_open_cache

The number of cached open tables

table_open_cache_instances

Maximum number of table cache instances

tcp_keepalive_interval

The interval, in seconds, between when successive keep-alive packets are sent if no acknowledgement is received.If set to 0, system dependent default is used

tcp_keepalive_probes

The number of unacknowledged probes to send before considering the connection dead and notifying the application layer.If set to 0, system dependent default is used

tcp_keepalive_time

Timeout, in seconds, with no activity until the first TCP keep-alive packet is sent.If set to 0, system dependent default is used

tcp_nodelay

Set option TCP_NODELAY (disable Nagle's algorithm) on socket

thread_cache_size

Controls how many threads are cached for use by new client connections. Threads are freed after 5 minutes of idle time.

thread_handling

Define threads usage for handling queries

thread_pool_dedicated_listener

If set to 1,listener thread will not pick up queries

thread_pool_exact_stats

If set to 1, provides better statistics in information_schema threadpool tables

thread_pool_idle_timeout

Timeout in seconds for an idle thread in the thread pool.Worker thread will be shut down after timeout

thread_pool_max_threads

Maximum allowed number of worker threads in the thread pool

thread_pool_min_threads

Minimum number of threads in the thread pool used on Microsoft Windows

thread_pool_oversubscribe

How many additional active worker threads in a group are allowed

thread_pool_prio_kickup_timer

The number of milliseconds before a dequeued low-priority statement is moved to the high-priority queue

thread_pool_priority

Threadpool priority. High priority connections usually start executing earlier than low priority.If priority set to 'auto', the the actual priority(low or high) is determined based on whether or not connection is inside transaction.

thread_pool_size

Number of thread groups in the pool. This parameter is roughly equivalent to maximum number of concurrently executing threads (threads in a waiting state do not count as executing).

thread_pool_stall_limit

Maximum query execution time in milliseconds,before an executing non-yielding thread is considered stalled.If a worker thread is stalled, additional worker thread may be created to handle remaining clients

thread_stack

The stack size for each thread

time_format

The TIME format (ignored)

time_zone

The current time zone, used to initialize the time zone for a client when it connects. Set to SYSTEM by default, in which the client uses the system time zone value.

timestamp

Set the time for this client

tls_version

TLS protocol version for secure connections

tmp_disk_table_size

Max size for data for an internal temporary on-disk MyISAM or Aria table

tmp_memory_table_size

If an internal in-memory temporary table exceeds this size, MariaDB will automatically convert it to an on-disk MyISAM or Aria table. Same as tmp_table_size.

tmp_table_size

Alias for tmp_memory_table_size. If an internal in-memory temporary table exceeds this size, MariaDB will automatically convert it to an on-disk MyISAM or Aria table.

tmpdir

Path for temporary files. Several paths may be specified, separated by a colon (:), in this case they are used in a round-robin fashion

transaction_alloc_block_size

Allocation block size for transactions to be stored in binary log

transaction_prealloc_size

Persistent buffer for transactions to be stored in binary log

tx_isolation

Sets the default transaction isolation level. SkySQL interfaces refer to this system variable as transaction_isolation.

tx_read_only

Default transaction access mode. If set to OFF, the default, access is read/write. If set to ON, access is read-only. The SET TRANSACTION statement can also change the value of this variable. See SET TRANSACTION and START TRANSACTION.

unique_checks

If set to 1, the default, secondary indexes in InnoDB tables are performed. If set to 0, storage engines can (but are not required to) assume that duplicate keys are not present in input data. Set to 0 to speed up imports of large tables to InnoDB. The storage engine will still issue a duplicate key error if it detects one, even if set to 0.

updatable_views_with_limit

YES = Don't issue an error message (warning only) if a VIEW without presence of a key of the underlying table is used in queries with a LIMIT clause for updating. NO = Prohibit update of a VIEW, which does not contain a key of the underlying table and the query uses a LIMIT clause (usually get from GUI tools)

use_stat_tables

Specifies how to use system statistics tables

userstat

Enables statistics gathering for USER_STATISTICS, CLIENT_STATISTICS, INDEX_STATISTICS and TABLE_STATISTICS tables in the INFORMATION_SCHEMA

version

Server version number. It may also include a suffix with configuration or build information. -debug indicates debugging support was enabled on the server, and -log indicates at least one of the binary log, general log or slow query log are enabled, for example 10.1.1-MariaDB-mariadb1precise-log.

version_comment

Value of the COMPILATION_COMMENT option specified by CMake when building MariaDB, for example mariadb.org binary distribution

version_compile_machine

The machine type or architecture MariaDB was built on, for example i686

version_compile_os

Operating system that MariaDB was built on, for example debian-linux-gnu

version_malloc_library

Version of the used malloc library

version_source_revision

Source control revision id for MariaDB source code

version_ssl_library

Version of the used SSL library

wait_timeout

The number of seconds the server waits for activity on a connection before closing it

warning_count

The number of errors, warnings, and notes that resulted from the last statement that generated messages

wsrep_auto_increment_control

To automatically control the assignment of autoincrement variables

wsrep_black_box_name

The name of the Black Box

wsrep_black_box_size

The size in bytes of the Black Box

wsrep_causal_reads

Setting this variable is equivalent to setting wsrep_sync_wait READ flag

wsrep_certification_rules

Certification rules to use in the cluster. Possible values are: "strict": stricter rules that could result in more certification failures. "optimized": relaxed rules that allow more concurrency and cause less certification failures.

wsrep_certify_nonpk

Certify tables with no primary key

wsrep_cluster_address

Address to initially connect to cluster

wsrep_cluster_name

Name for the cluster

wsrep_convert_lock_to_trx

To convert locking sessions into transactions

wsrep_data_home_dir

home directory for wsrep provider

wsrep_dbug_option

DBUG options to provider library

wsrep_debug

WSREP debug level logging

wsrep_desync

To desynchronize the node from the cluster

wsrep_dirty_reads

Permit read operations when the node is in a non-operational component

wsrep_drupal_282555_workaround

Enable a workaround to handle the cases where inserting a DEFAULT value into an auto-increment column could fail with duplicate key error

wsrep_forced_binlog_format

binlog format to take effect over user's choice

wsrep_gtid_domain_id

When wsrep_gtid_mode is set, this value is used as gtid_domain_id for galera transactions and also copied to the joiner nodes during state transfer. It is ignored, otherwise.

wsrep_gtid_mode

Automatically update the (joiner) node's wsrep_gtid_domain_id value with that of donor's (received during state transfer) and use it in place of gtid_domain_id for all galera transactions. When OFF (default), wsrep_gtid_domain_id is simply ignored (backward compatibility).

wsrep_gtid_seq_no

Internal server usage, manually set WSREP GTID seqno

wsrep_ignore_apply_errors

Ignore replication errors

wsrep_load_data_splitting

To commit LOAD DATA transaction after every 10K rows inserted (deprecated)

wsrep_log_conflicts

To log multi-master conflicts

wsrep_max_ws_rows

Max number of rows in write set

wsrep_max_ws_size

Max write set size (bytes)

wsrep_mysql_replication_bundle

mysql replication group commit

wsrep_node_address

Specifies the node's network address, in the format ip address[:port]. Used in situations where autoguessing is not reliable. As of MariaDB 10.1.8, supports IPv6.

wsrep_node_incoming_address

Client connection address

wsrep_node_name

Name of this node. This name can be used in wsrep_sst_donor as a preferred donor. Note that multiple nodes in a cluster can have the same name.

wsrep_notify_cmd

Command to execute upon changes in node state or cluster membership

wsrep_on

To enable wsrep replication

wsrep_osu_method

Method for Online Schema Upgrade

wsrep_patch_version

Wsrep patch version, for example wsrep_25.10

wsrep_provider

Path to replication provider library

wsrep_provider_options

Semicolon (;) separated list of wsrep options (see wsrep_provider_options documentation)

wsrep_recover

Recover database state after crash and exit

wsrep_reject_queries

Reject queries from client connections

wsrep_replicate_myisam

To enable myisam replication

wsrep_restart_slave

Should MariaDB slave be restarted automatically, when node joins back to cluster

wsrep_retry_autocommit

Number of autocommit retries the node attempts

wsrep_slave_fk_checks

Should slave thread do foreign key constraint checks

wsrep_slave_threads

Number of threads used in applying write-sets from the cluster

wsrep_slave_uk_checks

Should slave thread do secondary index uniqueness checks

wsrep_sr_store

Storage for streaming replication fragments

wsrep_sst_auth

Authentication for SST connection

wsrep_sst_donor

preferred donor node for the SST

wsrep_sst_donor_rejects_queries

Rejects blocking client sessions while node acts as a donor to a blocking SST operation

wsrep_sst_method

State snapshot transfer method

wsrep_sst_receive_address

Address where node is waiting for SST contact

wsrep_start_position

global transaction position to start from

wsrep_strict_ddl

If set, reject DDL on affected tables not supporting Galera replication

wsrep_sync_wait

Bitmask to configure synchronization waits for causality checks on the cluster

wsrep_trx_fragment_size

Size of transaction fragments for streaming replication (measured in units of 'wsrep_trx_fragment_unit')

wsrep_trx_fragment_unit

Unit for streaming replication transaction fragments' size: bytes, rows, statements

The following System Variables are not present in MariaDB Enterprise Server 10.5.22-16 but are present in one or more older 10.5 ES versions. Click on an item to see its details, including when it was removed.

Variable

Description

innodb_disallow_writes

Tell InnoDB to stop any writes to disk

innodb_idle_flush_pct

Up to what percentage of dirty pages should be flushed when innodb finds it has spare resources to do so

session_track_user_variables

Track changes to user variables

To see system variables supported in other versions, see "System Variables by MariaDB Server Version".