System Variables for MariaDB Enterprise Server 10.4
This page is part of MariaDB's Documentation.
The parent of this page is: Reference for MariaDB Enterprise Server 10.4
Topics on this page:
Overview
MariaDB Enterprise Server can be configured using system variables.
Reference material is available for MariaDB Enterprise Server 10.4.
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
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 10.4
Variable | Description |
|---|---|
Configures the server to use specific algorithms for ALTER TABLE operations | |
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. | |
Block size to be used for Aria index pages | |
Interval between tries to do an automatic checkpoints. In seconds; 0 means 'no automatic checkpoints' which makes sense only for testing. | |
Number of bytes that the transaction log has to grow between checkpoints before a new checkpoint is written to the log | |
Encrypt tables (only for tables with ROW_ | |
Number of consecutive log recovery failures after which logs will be automatically deleted to cure the problem; 0 (the default) disables the feature | |
Specifies Aria group commit mode. Possible values are "none" (no group commit), "hard" (with waiting to actual commit), "soft" (no wait for commit (DANGEROUS!!!)) | |
Interval between commite in microseconds (1/1000000c). 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_ | |
Path to the directory where to store transactional log | |
Limit for transaction log size | |
Specifies how Aria transactional log will be purged | |
Don't use the fast sort index method to created index if the temporary file would get bigger than this | |
Maintain page checksums (can be overridden per table with PAGE_ | |
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. | |
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. | |
The minimum percentage of warm blocks in key cache | |
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. | |
Specifies how corrupted tables should be automatically repaired | |
Number of threads to use when repairing Aria tables. The value of 1 disables parallel repair. | |
The buffer that is allocated when sorting the index when doing a REPAIR or when creating indexes with CREATE INDEX or ALTER TABLE | |
Specifies how Aria index statistics collection code should treat NULLs | |
Controls syncing directory after log file growth and new file creation | |
Whether temporary tables should be MyISAM or Aria | |
Auto-increment columns are incremented by this | |
Offset added to Auto-increment columns. Used when auto-increment-increment != 1 | |
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 | |
Creating and dropping stored procedures alters ACLs | |
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 | |
Path to installation directory. All paths are usually resolved relative to this | |
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. sql_ | |
IP address to bind to | |
Tells the master to annotate RBR events with the statement that caused these events | |
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 | |
Type of BINLOG_ | |
If non-zero, binlog write will wait at most binlog_ | |
Maximum time, in microseconds, to wait for more commits to queue up for binlog group commit. Only takes effect if the value of binlog_ | |
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_ | |
The size of file cache for the binary log | |
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. | |
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. | |
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). | |
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. | |
Size of tree cache used in bulk insert optimisation. Note that this is a limit per thread! | |
The character set for statements that arrive from the client | |
The character set used for literals that do not have a character set introducer and for number-to-string conversion | |
The character set used by the default database | |
The filesystem character set | |
The character set used for returning query results to the client | |
The default character set | |
The character set used by the server for storing identifiers | |
Directory where character sets are | |
check_ | |
The collation of the connection character set | |
The collation of the database character set | |
The server default collation | |
Minimum column data length eligible for compression | |
zlib compression level (1 gives best speed, 9 gives best compression) | |
The strategy parameter is used to tune the compression algorithm. Use the value DEFAULT_ | |
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. | |
The transaction completion type | |
Use concurrent insert with MyISAM | |
The number of seconds the mysqld server is waiting for a connect packet before responding with 'Bad handshake' | |
Write core on crashes | |
Path to the database root directory | |
The DATE format (ignored) | |
The DATETIME format (ignored) | |
Long search depth for the two-step deadlock detection | |
Short search depth for the two-step deadlock detection | |
Long timeout for the two-step deadlock detection (in microseconds) | |
Short timeout for the two-step deadlock detection (in microseconds) | |
Disable system thread alarm calls. Disabling it may be useful in debugging or testing, never do it in production | |
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 flags for the regex library | |
The default storage engine for new tables | |
The default storage engine for user-created temporary tables | |
The default week format used by WEEK() functions | |
Specifies how MyISAM tables handles CREATE TABLE DELAY_ | |
After inserting delayed_ | |
How long a INSERT DELAYED thread should wait for INSERT statements before terminating | |
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 | |
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. | |
Precision of the result of '/' operator will be increased on that value | |
Encrypt binary logs (including relay logs) | |
Encrypt temporary on-disk tables (created as part of query execution) | |
Encrypt temporary files (created for filesort, binary log cache, etc) | |
Force the use of a storage engine for new tables | |
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. | |
Enable the event scheduler. Possible values are ON, OFF, and DISABLED (keep the event scheduler completely deactivated, it cannot be activated run-time) | |
The maximum number of rows a subquery may examine in order to be executed during optimization and used for constant optimization | |
If non-zero, binary logs will be purged after expire_ | |
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 | |
The number of connections on extra-port | |
Extra port number to use for tcp connections in a one-thread-per-connection manner. 0 means don't use another port | |
Flush MyISAM tables to disk between SQL commands | |
A dedicated thread is created to flush all tables at the given interval | |
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. | |
List of operators for MATCH ... AGAINST ( ... IN BOOLEAN MODE) | |
The maximum length of the word to be included in a FULLTEXT index. Note: FULLTEXT indexes must be rebuilt after changing this variable | |
The minimum length of the word to be included in a FULLTEXT index. Note: FULLTEXT indexes must be rebuilt after changing this variable | |
Number of best matches to use for query expansion | |
Use stopwords from this file instead of built-in list | |
Log connections and queries to a table or log file. Defaults logging to a file 'hostname'.log or a table mysql.general_ | |
Log connections and queries to given file | |
The maximum length of the result of function GROUP_ | |
Last GTID logged to the binary log, per replicationdomain | |
The internal GTID state of the binlog, used to keep track of all GTIDs ever logged to the binlog | |
Normally does not need tuning. How many old rows must accumulate in the mysql.gtid_ | |
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. | |
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_ | |
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. | |
List of engines for which to automatically create a mysql.gtid_ | |
The list of global transaction IDs that were last replicated on the server, one for each replication domain | |
Enforce strict seq_ | |
Cache timeout for key data (in milliseconds) | |
Cache timeout for key version (in milliseconds) | |
Enable key caching (storing key values received from the Hashicorp Vault server in the local memory) | |
Enable kv storage version check during plugin initialization | |
Number of server request retries in case of timeout | |
Duration (in seconds) for the Hashicorp Vault server connection timeout | |
In case of timeout (when accessing the vault server) use the value taken from the cache | |
Path to the Certificate Authority (CA) bundle (is a file that contains root and intermediate certificates) | |
HTTP[s] URL that is used to connect to the Hashicorp Vault server | |
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. | |
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. | |
If the server supports dynamic loading of plugins, will be set to YES, otherwise will be set to NO | |
If the server supports spatial data types, will be set to YES, otherwise will be set to NO | |
Comparing have_ | |
If statement profiling is available, will be set to YES, otherwise will be set to NO. See SHOW PROFILES and SHOW PROFILE. | |
If the server supports the query cache, will be set to YES, otherwise will be set to NO | |
If RTREE indexes (used for spatial indexes) are available, will be set to YES, otherwise will be set to NO | |
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_ | |
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. | |
Number of bytes used for a histogram. If set to 0, no histograms are created by ANALYZE. | |
Specifies type of the histograms created by ANALYZE. Possible values are: SINGLE_ | |
How many host names should be cached to avoid resolving | |
Server host name | |
The number of seconds the server waits for read-only idle transaction | |
The number of seconds the server waits for idle transaction | |
The number of seconds the server waits for write idle transaction | |
Disable initialization of builtin InnoDB plugin | |
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. | |
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. | |
Command(s) that are executed for each new connection | |
Read SQL commands from this file at startup | |
Command(s) that are executed by a slave server each time the SQL thread starts | |
Attempt flushing dirty pages to avoid IO bursts at checkpoints | |
Percentage of log capacity below which no adaptive flushing happens | |
Enable InnoDB adaptive hash index (enabled by default). Disable with --skip-innodb-adaptive-hash-index. | |
Number of InnoDB Adaptive Hash Index Partitions (default 8) | |
The upper limit of the sleep delay in usec. Value of 0 disables it. | |
Data file autoextend increment in megabytes | |
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) | |
check if spaces needs scrubbing every innodb_ | |
Enable scrubbing of compressed data by background threads (same as encryption_ | |
scrub spaces that were last scrubbed longer than innodb_ | |
Enable scrubbing of uncompressed data by background threads (same as encryption_ | |
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). | |
Size of a single memory chunk within each buffer pool instance for resizing buffer pool. Online buffer pool resizing happens at this granularity. 0 means disable resizing buffer pool. | |
Dump the buffer pool into a file named @@innodb_ | |
Trigger an immediate dump of the buffer pool into a file named @@innodb_ | |
Dump only the hottest N% of each buffer pool, defaults to 25 | |
Filename to/from which to dump/load the InnoDB buffer pool | |
Number of buffer pool instances, set to higher value on high-end machines to increase scalability | |
Abort a currently running load of the buffer pool | |
Load the buffer pool from a file named @@innodb_ | |
Trigger an immediate load of the buffer pool from a file named @@innodb_ | |
The size of the memory buffer InnoDB uses to cache data and indexes of its tables | |
Maximum on-disk size of change buffer in terms of percentage of the buffer pool | |
Buffer changes to secondary indexes | |
The algorithm InnoDB uses for page checksumming. Possible values are FULL_ | |
Enable INFORMATION_ | |
Helps in performance tuning in heavily concurrent environments | |
Compression algorithm used on page compression. One of: none, zlib, lz4, lzo, lzma, bzip2, or snappy | |
Is compression the default for new tables | |
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 | |
Compression level used for zlib compression. 0 is no compression, 1 is fastest, 9 is best compression and default is 6. | |
Percentage of empty space on a data page that can be reserved to make the page compressible | |
Number of times a thread is allowed to enter InnoDB within the same SQL query after it has once got the ticket | |
Path to individual files and their sizes | |
The common part for InnoDB table spaces | |
Enable/disable InnoDB deadlock detector (default ON). if set to OFF, deadlock detection is skipped, and we rely on innodb_ | |
Default encryption key id used for table encryption | |
The default ROW FORMAT for all innodb tables created without explicit ROW_ | |
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. | |
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_ | |
How many records of space defragmentation should leave on the page. This variable, together with innodb_ | |
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_ | |
Number of pages considered at once when merging multiple pages to defragment | |
How many defragment stats changes there are before the stats are written to persistent storage. Set to 0 meaning disable defragment stats tracking. | |
Whether to disable OS system file cache for sort I/O | |
Enable InnoDB doublewrite buffer (enabled by default). Disable with --skip-innodb-doublewrite. | |
Enable redo log encryption | |
Enable encryption for tables. Don't forget to enable --innodb-encrypt-log too | |
Enrypt the temporary table data | |
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. | |
Use this many iops for background key rotation | |
Number of threads performing background key rotation and scrubbing | |
Speeds up the shutdown process of the InnoDB storage engine. Possible values are 0, 1 (faster), 2 (crash-like), 3 (fastest clean). | |
Maximum number of seconds that semaphore times out in InnoDB | |
Deprecated parameter with no effect | |
Stores each InnoDB table to an .ibd file in the database dir | |
Percentage of B-tree page filled during bulk insert | |
Write and flush logs every (n) second | |
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. | |
With which method to flush data | |
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 | |
Allow IO bursts at the checkpoints ignoring io_ | |
Number of iterations over which the background flushing is averaged | |
Force InnoDB to load metadata of corrupted table | |
Do not allow to create table without primary key (off by default) | |
Helps to save your data in case the disk image of the database becomes corrupt | |
FTS internal auxiliary table to be checked | |
InnoDB Fulltext search cache size in bytes | |
Whether to enable additional FTS diagnostic printout | |
Create FTS index with stopword | |
InnoDB Fulltext search maximum token size in characters | |
InnoDB Fulltext search minimum token size in characters | |
InnoDB Fulltext search number of words to optimize for each optimize table call | |
InnoDB Fulltext search query result cache limit in bytes | |
The user supplied stopword table name | |
InnoDB Fulltext search parallel sort degree, will round up to nearest power of 2 number | |
Total memory allocated for InnoDB Fulltext Search cache | |
User supplied stopword table name, effective in the session level | |
DEPRECATED. This setting has no effect. | |
Enable scrubbing of data | |
File format constraint for ALTER TABLE | |
Number of IOPs the server can do. Tunes the background IO rate | |
Limit to which innodb_ | |
Deprecated parameter with no effect | |
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. | |
Timeout in seconds an InnoDB transaction may wait for a lock before being rolled back. Values above 100000000 disable the timeout. | |
DEPRECATED. This option may be removed in future releases. Please use READ COMMITTED transaction isolation level instead. Force InnoDB to not use next-key locking, to use only row-level locking. | |
The size of the buffer which InnoDB uses to write log to the log files on disk | |
DEPRECATED. Whether to require checksums for InnoDB redo log blocks. | |
Enables/disables the logging of entire compressed page images. InnoDB logs the compressed pages to prevent corruption if the zlib compression algorithm changes. When turned OFF, InnoDB will assume that the zlib compression algorithm doesn't change. | |
Size of each log file in a log group | |
Number of log files in the log group. InnoDB writes to the files in a circular fashion. | |
Path to InnoDB log files | |
DEPRECATED. Ignored in MariaDB 10.5. Reduce redo logging when natively creating indexes or rebuilding tables. Enabling this may slow down backup and cause delay due to page flushing. | |
Redo log write ahead unit size to avoid read-on-write, it should match the OS cache block IO size | |
How deep to scan LRU to keep it clean | |
Percentage of dirty pages allowed in bufferpool | |
Percentage of dirty pages at which flushing kicks in | |
Desired maximum length of the purge queue (0 = no limit) | |
Maximum delay of user threads in micro-seconds | |
Wait until History list length is below the specified limit | |
Desired maximum UNDO tablespace size in bytes | |
Turn off a monitor counter | |
Turn on a monitor counter | |
Reset a monitor counter | |
Reset all values for a monitor counter | |
Percentage of the buffer pool to reserve for 'old' blocks | |
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. | |
Maximum modification log file size for online index creation | |
How many files at the maximum InnoDB keeps open at the same time | |
Only optimize the Fulltext index of the table | |
Page cleaner threads can be from 1 to 64. Default is 4. | |
Page size to use for all InnoDB tablespaces | |
Enable prefix optimization to sometimes avoid cluster index lookups | |
Print all deadlocks to MariaDB error log (off by default) | |
Number of UNDO log pages to purge in one batch from the history list | |
Dictates rate at which UNDO records are purged. Value N means purge rollback segment(s) on every Nth iteration of purge invocation | |
Purge threads can be from 1 to 32. Default is 4. | |
Whether to use read ahead for random access within an extent | |
Number of pages that must be accessed sequentially for InnoDB to trigger a readahead | |
Number of background read I/O threads in InnoDB | |
Start InnoDB in read only mode (off by default) | |
Replication thread delay (ms) on the slave server if innodb_ | |
Roll back the complete transaction on lock wait timeout, for 4.x compatibility (disabled by default) | |
Number of undo logs to use (deprecated) | |
Enable background redo log (ib_ | |
Background redo log scrubbing speed in bytes/sec | |
Memory buffer size for index creation | |
Maximum delay between polling for a spin lock (4 by default) | |
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) | |
Include delete marked records when calculating persistent statistics | |
Specifies how InnoDB index statistics collection code should treat NULLs. Possible values are NULLS_ | |
The number of rows modified before we calculate new statistics (default 0 = current limits) | |
Enable statistics gathering for metadata commands such as SHOW TABLE STATUS for tables that use transient statistics (off by default) | |
InnoDB persistent statistics enabled for all tables unless overridden at table level | |
The number of leaf index pages to sample when calculating persistent statistics (by ANALYZE, default 20) | |
Deprecated, use innodb_ | |
Enable traditional statistic calculation based on number of configured pages (default true) | |
The number of leaf index pages to sample when calculating transient statistics (if persistent statistics are not used, default 8) | |
Enable InnoDB monitor output to the error log | |
Enable InnoDB lock monitor output to the error log. Requires innodb_ | |
Use strict mode when evaluating create options | |
Size of the mutex/lock wait array | |
Count of spin-loop rounds in InnoDB mutexes (30 by default) | |
Enable InnoDB locking in LOCK TABLES | |
Path to files and their sizes making temp-tablespace | |
Helps in performance tuning in heavily concurrent environments. Sets the maximum number of threads allowed inside InnoDB. Value 0 will disable the thread throttling. | |
Time of innodb thread sleeping before joining InnoDB queue (usec). Value 0 disable a sleep | |
Directory for temporary non-tablespace files | |
Directory where undo tablespace files live, this path can be absolute | |
Enable or Disable Truncate of UNDO tablespace | |
Number of undo logs to use | |
Number of undo tablespaces to use | |
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. | |
Use native AIO if supported on this platform | |
InnoDB version | |
Number of background write I/O threads in InnoDB | |
The number of seconds the server waits for activity on an interactive connection before closing it | |
The size of the buffer that is used for joins | |
The limit of the space for all join buffers used by a query | |
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 | |
Don't overwrite stale .MYD and .MYI even if no directory is specified | |
The size in bytes of MyISAM key cache, which is the buffer used for MyISAM index blocks | |
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 | |
The default size of key cache blocks | |
The minimum percentage of warm blocks in key cache | |
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. | |
The number of segments in a key cache | |
Whether mysqld was compiled with options for large file support | |
If large page support is enabled, this shows the size of memory pages | |
Enable support for large pages | |
Set the language used for the error messages | |
Directory where error messages are | |
Set the language used for the month names and the days of the week | |
The type of license the server has | |
Enable LOAD DATA LOCAL INFILE | |
Timeout in seconds to wait for a lock before returning an error | |
Whether mysqld was locked in memory with --memlock | |
Whether the binary log is enabled | |
The full path of the binary log file names, excluding the extension | |
Whether the binary log can be compressed | |
Minimum length of sql statement(in statement mode) or record(in row mode)that can be compressed | |
File that holds the names for last binary log files | |
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 | |
Don't log certain types of statements to general log | |
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 | |
How logs should be written | |
Log queries that are executed without benefit of any index to the slow log if it is open. Same as log_ | |
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 OPTIMIZE, ANALYZE, ALTER and other administrative statements to the slow log if it is open. Resets or sets the option 'admin' in log_ | |
Don't log certain types of statements to slow log | |
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_ | |
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 statements executed by slave thread to the slow log if it is open. Resets or sets the option 'slave' in log_ | |
Verbosity level for the slow log | |
Size of transaction coordinator log | |
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. | |
Log all queries that have taken more than long_ | |
INSERT/DELETE/UPDATE has lower priority than selects | |
Case sensitivity of file names on the file system where the data directory is located | |
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 | |
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 packet length to send to or receive from the server | |
Sets the total size of the transactional cache | |
Binary log will be rotated automatically when the size exceeds this value | |
Sets the total size of the statement cache | |
If there is more than this number of interrupted connections from a host this host will be blocked from further connections | |
Maximum number of clients allowed to connect concurrently | |
Don't start more than this number of threads to handle INSERT DELAYED statements. If set to zero INSERT DELAYED will be not used | |
Maximum length considered for digest text | |
Max number of errors/warnings to store for a statement | |
Don't allow creation of heap tables bigger than this | |
Don't start more than this number of threads to handle INSERT DELAYED statements. If set to zero INSERT DELAYED will be not used | |
Joins that are probably going to read more than max_ | |
Max number of bytes in sorted records | |
The maximum BLOB length to send to server from mysql_ | |
If there is more than this number of failed connect attempts due to invalid password, user will be blocked from further connections until | |
Maximum number of prepared statements in the server | |
Maximum number of iterations when executing recursive queries | |
relay log will be rotated automatically when the size exceeds this value. If 0 at startup, it's set to max_ | |
The maximum size of the container of a rowid filter | |
Limit assumed max number of seeks when looking up rows based on a key | |
Amount of memory a single user session is allowed to allocate. This limits the value of the session variable MEM_ | |
The number of bytes to use when sorting BLOB or TEXT values (only the first max_ | |
Maximum stored procedure recursion depth | |
A query that has taken more than max_ | |
Unused, will be removed | |
The maximum number of active connections for a single user (0 = no limit) | |
After this many write locks, allow some read locks to run in between | |
Unused | |
Unused | |
Don't write queries to slow log that examine fewer rows than that | |
Size of buffer to use when using MRR with range access | |
Ignored. Use mrr_ | |
Block size to be used for MyISAM index pages | |
Default pointer size to be used for MyISAM tables | |
Don't use the fast sort index method to created index if the temporary file would get bigger than this | |
Restricts the total memory used for memory mapping of MySQL tables | |
Specifies how corrupted tables should be automatically repaired | |
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 | |
The buffer that is allocated when sorting the index when doing a REPAIR or when creating indexes with CREATE INDEX or ALTER TABLE | |
Specifies how MyISAM index statistics collection code should treat NULLs. Possible values of name are NULLS_ | |
Use memory mapping for reading and writing MyISAM tables | |
Use MySQL-5.6 (instead of MariaDB-5.3) format for TIME, DATETIME, TIMESTAMP columns | |
Buffer length for TCP/IP and socket communication | |
Number of seconds to wait for more data from a connection before aborting the read | |
If a read on a communication port is interrupted, retry this many times before giving up | |
Number of seconds to wait for a block to be written to a connection before aborting the write | |
Use compatible behavior from previous MariaDB version. See also --old-mode | |
Alias for alter_ | |
Used to emulate old behavior from earlier MariaDB or MySQL versions | |
Use old password encryption method (needed for 4.0 and older clients) | |
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_ | |
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 | |
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. | |
Controls number of record samples to check condition selectivity | |
Fine-tune the optimizer behavior | |
Controls tracing of the Optimizer: optimizer_ | |
Maximum allowed size of an optimizer trace | |
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 | |
Password history retention period in days (0 means unlimited) | |
Enable the performance schema | |
Maximum number of instrumented user@host accounts. Use 0 to disable, -1 for automated sizing. | |
Size of the statement digest. Use 0 to disable, -1 for automated sizing. | |
Number of rows in EVENTS_ | |
Number of rows per thread in EVENTS_ | |
Number of rows in EVENTS_ | |
Number of rows per thread in EVENTS_ | |
Number of rows in EVENTS_ | |
Number of rows per thread in EVENTS_ | |
Maximum number of instrumented hosts. Use 0 to disable, -1 for automated sizing. | |
Maximum number of condition instruments | |
Maximum number of instrumented condition objects. Use 0 to disable, -1 for automated sizing. | |
Maximum length considered for digest text, when stored in performance_ | |
Maximum number of file instruments | |
Maximum number of opened instrumented files | |
Maximum number of instrumented files. Use 0 to disable, -1 for automated sizing. | |
Maximum number of mutex instruments | |
Maximum number of instrumented MUTEX objects. Use 0 to disable, -1 for automated sizing. | |
Maximum number of rwlock instruments | |
Maximum number of instrumented RWLOCK objects. Use 0 to disable, -1 for automated sizing. | |
Maximum number of socket instruments | |
Maximum number of opened instrumented sockets. Use 0 to disable, -1 for automated sizing. | |
Maximum number of stage instruments | |
Maximum number of statement instruments | |
Maximum number of opened instrumented tables. Use 0 to disable, -1 for automated sizing. | |
Maximum number of instrumented tables. Use 0 to disable, -1 for automated sizing. | |
Maximum number of thread instruments | |
Maximum number of instrumented threads. Use 0 to disable, -1 for automated sizing. | |
Size of session attribute string buffer per thread. Use 0 to disable, -1 for automated sizing. | |
Maximum number of rows in SETUP_ | |
Maximum number of rows in SETUP_ | |
Maximum number of instrumented users. Use 0 to disable, -1 for automated sizing. | |
Pid file used by safe_ | |
Directory for plugins | |
The lowest desirable plugin maturity. Plugins less mature than that will not be installed or loaded | |
Port number to use for connection or 0 to default to, my.cnf, $MYSQL_ | |
The size of the buffer that is allocated when preloading indexes | |
If set to 1 (0 is default), statement profiling will be enabled. See SHOW PROFILES and SHOW PROFILE. | |
Number of statements about which profiling information is maintained. If set to 0, no profiles are stored. See SHOW PROFILES. | |
Seconds between sending progress reports to the client for time-consuming statements. Set to 0 to disable progress reporting. | |
The version of the client/server protocol used by the MariaDB server | |
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). | |
Allocation block size for query parsing and execution | |
Don't cache results that are bigger than this | |
The minimum size for blocks allocated by the query cache | |
The memory allocated to store results from old queries | |
Strip all comments from a query before storing it in the query cache | |
OFF = Don't cache or retrieve results. ON = Cache all results except SELECT SQL_ | |
Invalidate queries in query cache on LOCK for write | |
Persistent buffer for query parsing and execution | |
Allocation block size for storing ranges during optimization | |
Maximum speed(KB/s) to read binlog from master (0 = no limit) | |
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 | |
Make all non-temporary tables read-only, with the exception for replication (slave) threads and users with the SUPER privilege | |
When reading rows in sorted order after a sort, the rows are read through this buffer to avoid a disk seeks | |
The location and name to use for relay logs | |
The full path of the relay log file names, excluding the extension | |
The location and name to use for the file that keeps a list of the last relay logs | |
The location and name of the file that remembers where the SQL replication thread is in the relay logs | |
if disabled - do not purge relay logs. if enabled - purge them as soon as they are no more needed. | |
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 | |
Maximum space to use for all relay logs | |
Tells the slave to write annotate rows events received from the master to its own binary log. Ignored if log_ | |
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. | |
Tells the slave to restrict replication to tables in the comma-separated list | |
Whether the slave should replicate events that were created with @@skip_ | |
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. | |
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 | |
Tells the slave thread to restrict replication to statements where any of the updated tables match the specified database and table name patterns | |
Tells the slave thread to not replicate to the tables that match the given wildcard pattern | |
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 | |
The account password of the slave to be reported to the master during slave registration | |
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 | |
The account user name of the slave to be reported to the master during slave registration | |
When this option is enabled, connections attempted using insecure transport will be rejected. Secure transports are SSL/TLS, Unix sockets or named pipes. | |
Ignore MyRocks' data directory errors. (CAUTION: Use only to start the server and perform repairs. Do NOT use for regular operation) | |
The size of the buffers used [NOT] IN evaluation via partial matching | |
Enable semi-synchronous replication master (disabled by default) | |
The timeout value (in ms) for semi-synchronous replication in the master | |
The tracing level for semi-sync replication | |
Wait until timeout when no semi-synchronous replication slave available (enabled by default) | |
Should transaction wait for semi-sync ack after having synced binlog, or after having committed in storage engine | |
Only write master info file when ack is needed | |
Enable semi-synchronous replication slave (disabled by default) | |
Timeout for the mysql connection used to kill the slave io_ | |
The tracing level for semi-sync replication | |
Disallow authentication for accounts that have old (pre-4.1) passwords | |
Limit LOAD DATA, SELECT ... OUTFILE, and LOAD_ | |
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 | |
Path to the log file | |
Force log rotation now | |
Maximum size of the log to start the rotation | |
Number of rotations before log is removed | |
Do not load the plugin if filter definitions are invalid | |
Turn on/off the logging | |
Auditing mode | |
Desired output type. Possible values - 'syslog', 'file' or 'null' as no output. | |
Limit on the length of the query string in a record | |
Reload filter definitions from tables | |
The 'facility' parameter of the SYSLOG record. The default is LOG_ | |
The SYSLOG identifier - the beginning of each SYSLOG record | |
The <info> string to be added to the SYSLOG record | |
The 'priority' parameter of the SYSLOG record. The default is LOG_ | |
Uniquely identifies the server instance in the community of replication partners | |
Track changes to the default schema | |
Track changes to the session state | |
Track changes in registered system variables | |
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). | |
when ON, SHUTDOWN command runs with implicit WAIT FOR ALL SLAVES option | |
Minimal required number of digits | |
Minimal required number of letters of the same letter case.This limit is applied separately to upper-case and lower-case letters | |
Minimal required password length | |
Minimal required number of other (not letters or digits) characters | |
Don't use system (external) locking | |
Don't resolve hostnames. All hostnames are IP's or 'localhost'. | |
Don't allow connection with TCP/IP | |
Don't allow 'SHOW DATABASE' commands | |
Use compression on master/slave protocol | |
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. | |
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_ | |
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. | |
The location where the slave should put its temporary files when replicating a LOAD DATA INFILE command | |
The maximum packet length to sent successfully from the master to slave | |
Number of seconds to wait for more data from any master/slave connection before aborting the read | |
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. | |
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. | |
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 | |
Alias for slave_ | |
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. | |
Tells the slave thread to continue replication when a query event returns an error from the provided list | |
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 | |
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_ | |
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 | |
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_ | |
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. | |
If creating the thread takes longer than this value (in seconds), the Slow_ | |
Log slow queries to a table or log file. Defaults logging to a file 'hostname'-slow.log or a table mysql.slow_ | |
Log slow queries to given log file. Defaults logging to 'hostname'-slow.log. Must be enabled to activate other slow log options | |
Socket file to use for connection | |
Each thread that needs to do a sort allocates a buffer of this size | |
Buffer size | |
Pushdown aggregation functions if possible | |
If set to 1, the query SELECT * FROM table_ | |
If set to 0, MariaDB will not perform large SELECTs. See max_ | |
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. | |
If set to 1 adds an implicate IF EXISTS to ALTER, RENAME and DROP of TABLES, VIEWS, FUNCTIONS and PACKAGES | |
Controls if the client's queries are logged to the binary log for replication. | |
Controls if the client's queries are left out of the general query log. | |
Overrides the default behavior of the server in several contexts | |
If set to 1, the default, warning_ | |
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. | |
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. | |
The maximum number of rows to return from SELECT statements | |
Skip the next N events from the master log | |
If set to 1, single-row INSERTs will produce a string containing warning information if a warning occurs | |
CA file in PEM format (check OpenSSL docs, implies --ssl) | |
CA directory (check OpenSSL docs, implies --ssl) | |
X509 cert in PEM format (implies --ssl) | |
SSL cipher to use (implies --ssl) | |
CRL file in PEM format (check OpenSSL docs, implies --ssl) | |
CRL directory (check OpenSSL docs, implies --ssl) | |
X509 key in PEM format (implies --ssl) | |
Allow only CTEs compliant to SQL standard | |
Alias for @@default_ | |
The soft upper limit for number of cached stored routines for one connection | |
When password validation plugins are enabled, reject passwords that cannot be validated (passwords specified as a hash) | |
Synchronously flush binary log to disk after every #th event. Use 0 (default) to disable synchronous flushing | |
Sync .frm files to disk on creation | |
Synchronously flush master info to disk after every #th event. Use 0 to disable synchronous flushing | |
Synchronously flush relay log to disk after every #th event. Use 0 to disable synchronous flushing | |
Synchronously flush relay log info to disk after every #th transaction. Use 0 to disable synchronous flushing | |
Sets the server's system time zone. | |
Versioning ALTER TABLE mode. ERROR: Fail ALTER with error; KEEP: Keep historical system rows and subject them to ALTER | |
Default value for the FOR SYSTEM_ | |
The number of cached table definitions | |
The number of cached open tables | |
Maximum number of table cache instances | |
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 | |
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 | |
Timeout, in seconds, with no activity until the first TCP keep-alive packet is sent.If set to 0, system dependent default is used | |
Set option TCP_ | |
Controls how many threads are cached for use by new client connections. Threads are freed after 5 minutes of idle time. | |
Permits the application to give the threads system a hint for the desired number of threads that should be run at the same time.This variable has no effect, and is deprecated. It will be removed in a future release. | |
Define threads usage for handling queries | |
Timeout in seconds for an idle thread in the thread pool.Worker thread will be shut down after timeout | |
Maximum allowed number of worker threads in the thread pool | |
How many additional active worker threads in a group are allowed | |
The number of milliseconds before a dequeued low-priority statement is moved to the high-priority queue | |
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. | |
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). | |
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 | |
The stack size for each thread | |
The TIME format (ignored) | |
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. | |
Specify whether to time mutexes. Deprecated, has no effect. | |
TLS protocol version for secure connections | |
Max size for data for an internal temporary on-disk MyISAM or Aria table | |
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_ | |
Alias for tmp_ | |
Path for temporary files. Several paths may be specified, separated by a colon (:), in this case they are used in a round-robin fashion | |
Allocation block size for transactions to be stored in binary log | |
Persistent buffer for transactions to be stored in binary log | |
Sets the default transaction isolation level. | |
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. | |
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. | |
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) | |
Specifies how to use system statistics tables | |
Enables statistics gathering for USER_ | |
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. | |
Value of the COMPILATION_ | |
The machine type or architecture MariaDB was built on, for example i686 | |
Operating system that MariaDB was built on, for example debian-linux-gnu | |
Version of the used malloc library | |
Source control revision id for MariaDB source code | |
Version of the used SSL library | |
The number of seconds the server waits for activity on a connection before closing it |
The following System Variables are not present in MariaDB Enterprise Server 10.4.31-21 but are present in one or more older 10.4 ES versions. Click on an item to see its details, including when it was removed.
Variable | Description |
|---|---|
Controls compression algorithm for create tables. Possible values are: NO_ | |
The default decimal precision for calculated column sub-operations | |
Enable/Disable the MCS derived_ | |
The maximum size in MB of each 'small side' table in memory | |
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) | |
The maximum amount of disk space in MB to use per query for storing 'small side' tables for a disk-based join. (0 = unlimited) | |
Enable/disable for ColumnStore to replace DECIMAL with DOUBLE in arithmetic operation | |
Enable/Disable the MCS group_ | |
ASCII value of the delimiter used by LDI and INSERT..SELECT | |
ASCII value of the quote symbol used by batch data ingestion | |
Enable/disable the ColumnStore local PM query only feature | |
Number of parallel threads used by ORDER BY. (default to 16) | |
Always use the first table in the from clause as the large side table for joins | |
Allow this MariaDB server to apply replication changes to ColumnStore | |
Enables the ColumnStore select handler, which allows ColumnStore to plan its own queries | |
Max number of blocks in a dictionary file to be scanned for filtering | |
The minimum width of a string column to be stored in a string table | |
Per user Memory limit(MB). Switch to disk-based JOIN when limit is reached | |
Enable/disable the MCS decimal scale to be used internally | |
LOAD DATA INFILE and INSERT..SELECT will use cpimport internally | |
Always display/process varbinary columns as if they have been hexified | |
Tell InnoDB to stop any writes to disk |
To see system variables supported in other versions, see "System Variables by MariaDB Server Version".