System Variables for MariaDB Community Server 10.2
This page is part of MariaDB's Documentation.
The parent of this page is: Reference for MariaDB Community Server 10.2
Topics on this page:
Overview
MariaDB Community Server can be configured using system variables.
Reference material is available for MariaDB Community Server 10.2.
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_
$ 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 Community Server supports many system variables.
System Variables for MariaDB Community Server 10.2
Variable | Description |
|---|---|
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_ | |
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 | |
Encryption algorithm used to create new keys | |
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 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. | |
Mock AWS KMS calls (for testing). Must be enabled at compile-time. | |
AWS region name, e.g., us-east-1 . Default is SDK default, which is us-east-1. | |
Timeout in milliseconds for create HTTPS connection or execute AWS request. Specify 0 to use SDK default. | |
Set this variable to a data key ID to perform rotation of the key to the master key given in aws_ | |
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_ | |
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_ | |
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 | |
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 a core-file on crashes | |
Path to a cracklib dictionary | |
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) | |
Available in debug builds only (built with -SWITH_ | |
Disable system thread alarm calls. Disabling it may be useful in debugging or testing, never do it in production | |
Used in debugging to show the interface to the Debug Sync facility. MariaDB needs to be configured with -DENABLE_ | |
Master connection to use for all slave variables and slave commands | |
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 | |
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. | |
The number of errors that resulted from the last statement that generated messages | |
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 old behavior is deprecated. | |
The external user account used when logging in | |
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 | |
Proxy server host:port | |
Wait this many seconds before retrying a failed send | |
Timeout (in seconds) for the sending the report | |
Automatically calculated server unique id hash | |
Space separated URLs to send the feedback report to | |
User specified string that will be included in the feedback report | |
Encryption algorithm to use, aes_ | |
Key to encrypt / decrypt the keyfile | |
Path and name of the key file | |
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_ | |
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. | |
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. | |
Name of the service principal | |
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 | |
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. | |
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. | |
The list of global transaction IDs that were last replicated on the server, one for each replication domain | |
Enforce strict seq_ | |
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 | |
Synonym for the last_ | |
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. | |
Whether there is an active transaction | |
Command(s) that are executed for each new connection (unless the user has SUPER privilege) | |
Read SQL commands from this file at startup | |
Command(s) that are executed by a slave server each time the SQL thread starts | |
Replaced with innodb_ | |
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. | |
It is an alias for innodb_ | |
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 | |
Used in testing InnoDB Buffer Pool | |
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_ | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 reduce random access: OFF, ON, inserting, deleting, changing, or purging | |
Used in debugging builds for InnoDB | |
The algorithm InnoDB uses for page checksumming. Possible values are CRC32 (hardware accelerated if the CPU supports it) write crc32, allow any of the other checksums to match when reading; STRICT_ | |
DEPRECATED. Use innodb_ | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
Tell InnoDB to stop any writes to disk | |
Enable InnoDB doublewrite buffer (enabled by default). Disable with --skip-innodb-doublewrite. | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Speeds up the shutdown process of the InnoDB storage engine. Possible values are 0, 1 (faster) or 2 (fastest - crash-like). | |
Maximum number of seconds that semaphore times out in InnoDB | |
File format to use for new tables in .ibd files | |
Whether to perform system file format check | |
The highest file format in the tablespace | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
DEPRECATED. This setting has no effect. | |
Number of IOPs the server can do. Tunes the background IO rate | |
Limit to which innodb_ | |
No effect for this build | |
Support large index prefix length of REC_ | |
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 and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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. | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
The size of the buffer which InnoDB uses to write log to the log files on disk | |
Deprecated and translated to innodb_ | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Turn off a monitor counter | |
Turn on a monitor counter | |
Reset a monitor counter | |
Reset all values for a monitor counter | |
DEPRECATED. Number of multi-threaded flush threads | |
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) | |
Use backup-safe TRUNCATE TABLE and crash-safe RENAME (incompatible with older MariaDB 10.2; ON by default) | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Enable background redo log (ib_ | |
Background redo log scrubbing speed in bytes/sec | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 | |
Enable InnoDB support for the XA two-phase commit | |
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 | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
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 posix_ | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
DEPRECATED. Use multi-threaded flush. Default FALSE. | |
Use native AIO if supported on this platform | |
Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions | |
Deallocate (punch_ | |
InnoDB version | |
Number of background write I/O threads in InnoDB | |
The value to be used by the following INSERT or ALTER TABLE statement when inserting an AUTO_ | |
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 | |
The GTID of the last commit (if binlogging was enabled), or the empty string if none | |
The value to be returned from LAST_ | |
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 | |
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 | |
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 | |
Log only certain types of queries | |
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 | |
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_ | |
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_ | |
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 | |
Use old, non-optimized alter table | |
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 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 | |
Used in debugging builds PAM authentication plugin | |
Use mysql_ | |
Compare usernames case insensitively to work around pam_ | |
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 | |
The proxy user account name used when logging in | |
SET pseudo_ | |
This variable is for internal server use | |
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 | |
Used in debugging builds for tracking query response time execution times | |
Update of this variable flushes statistics and re-reads query_ | |
Select base of log for query_ | |
Enable or disable query response time statisics collecting | |
Sets the internal state of the RAND() generator for replication purposes | |
Sets the internal state of the RAND() generator for replication purposes | |
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 | |
DBOptions::access_ | |
DBOptions::advise_ | |
DBOptions::allow_ | |
DBOptions::allow_ | |
DBOptions::allow_ | |
Allow server still to start successfully even if RocksDB corruption is detected | |
Deleting rows by primary key lookup, without reading rows (Blind Deletes). Blind delete is disabled if the table has secondary key | |
block_ | |
BlockBasedTableOptions::block_ | |
BlockBasedTableOptions::block_ | |
BlockBasedTableOptions::block_ | |
Use bulk-load mode for inserts. This disables unique_ | |
Allow bulk loading of sk keys during bulk-load. Can be changed only when bulk load is disabled. | |
Allow unsorted input during bulk-load. Can be changed only when bulk load is disabled. | |
Max #records in a batch for bulk-load mode | |
DBOptions::bytes_ | |
Include RocksDB block cache content in core dump | |
Specify the size of block cache high-pri pool | |
BlockBasedTableOptions::cache_ | |
cache_ | |
How many percentages of rows to be checksummed | |
Enables collecting SST file properties on each flush | |
Commit rows implicitly every rocksdb_ | |
TransactionOptions::commit_ | |
Compact column family | |
DBOptions::compaction_ | |
RocksDB will trigger compaction for the file if it has more than this number sequential deletes per window | |
Counting SingleDelete as rocksdb_ | |
Minimum file size required for compaction_ | |
Size of the window for counting rocksdb_ | |
Checkpoint directory | |
DBOptions::create_ | |
DBOptions::create_ | |
RocksDB data directory | |
DBOptions::db_ | |
Enables deadlock detection | |
Number of transactions deadlock detection will traverse through before assuming deadlock | |
For debugging purposes only. Sleeping specified seconds for simulating long running compactions. | |
In case if cardinality is zero, overrides it with some value | |
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. | |
For debugging purposes only. Overrides the TTL read filtering time to time + debug_ | |
For debugging purposes only. Overrides the TTL of records to now() + debug_ | |
For debugging purposes only. Sets the snapshot during compaction to now() + debug_ | |
default cf options for RocksDB | |
DBOptions::delayed_ | |
Delete column family | |
DBOptions::delete_ | |
Enable two phase commit for MyRocks | |
Enables using SstFileWriter for bulk loading | |
Whether to enable optimization where we cache the read from a failed insertion attempt in INSERT ON DUPLICATE KEY UPDATE | |
DBOptions::enable_ | |
Enable expired TTL records to be dropped during compaction | |
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. | |
DBOptions::enable_ | |
DBOptions::error_ | |
Raise an error instead of warning if a sub-optimal collation is used | |
Sync on transaction commit. Similar to innodb_ | |
Force to always compute memtable stats | |
Time in usecs to cache memtable estimates | |
Acts similar to force_ | |
Forces memstore flush which may block all write requests so be careful | |
Used to override the result of records_ | |
Git revision of the RocksDB library used by MyRocks | |
BlockBasedTableOptions::hash_ | |
Ignore MyRocks' data directory errors. (CAUTION: Use only to start the server and perform repairs. Do NOT use for regular operation) | |
Enable ignoring unknown options passed to RocksDB | |
BlockBasedTableOptions::index_ | |
Filter level for info logs to be written mysqld error log. Valid values include 'debug_ | |
Timeout for experimental I/O watchdog | |
DBOptions::is_ | |
DBOptions::keep_ | |
Support large index prefix length of 3072 bytes. If off, the maximum index prefix length is 767. | |
Take and hold locks on rows that are scanned but not updated | |
Number of seconds to wait for lock | |
DBOptions::log_ | |
DBOptions::manifest_ | |
How many rocksdb threads to run for manual compactions | |
DBOptions::manual_ | |
Skipping holding any lock on row access. Not effective on slave. | |
DBOptions::max_ | |
Maximum number of recent deadlocks to store | |
DBOptions::max_ | |
DBOptions::max_ | |
Maximum number of pending + ongoing number of manual compactions | |
DBOptions::max_ | |
Maximum number of locks a transaction can have | |
DBOptions::max_ | |
DBOptions::max_ | |
Size to allocate for merge sort buffers written out to disk during inplace index creation | |
Size that we have to work with during combine (reading from disk) phase of external sort during fast index creation | |
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_ | |
DBOptions::new_ | |
BlockBasedTableOptions::no_ | |
option overrides per cf for RocksDB | |
DBOptions::paranoid_ | |
Disable all rocksdb background operations | |
Perf Context Level for rocksdb internal timer stat collection | |
Path for BlockBasedTableOptions::persistent_ | |
Size of cache in MB for BlockBasedTableOptions::persistent_ | |
pin_ | |
Logging queries that got snapshot conflict errors into *.err log | |
DBOptions::rate_ | |
Used to override the result of records_ | |
Remove mariabackup checkpoint | |
Reset the RocksDB internal statistics without restarting the DB | |
Whether to roll back the complete transaction or a single statement on lock wait timeout (a single statement by default) | |
Sets a number of seconds to wait between optimizer stats recomputation. Only changed indexes will be refreshed. | |
Wake up drop index thread | |
Simulated cache size for RocksDB | |
Skip using bloom filter for reads | |
Skip filling block cache on read requests | |
Skip unique constraint checking for the specified tables | |
DBOptions::sst_ | |
DBOptions::stats_ | |
Statistics Level for RocksDB. Default is 0 (kExceptHistogramOrTimers) | |
The number of indexes per second to recalculate statistics for. 0 to disable background recalculation. | |
Include checksums when writing index/table records | |
Enforce case sensitive collation for MyRocks indexes | |
List of tables (using regex) that are excluded from the case sensitive collation enforcement | |
Compression algorithms supported by RocksDB | |
DBOptions::table_ | |
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. | |
Directory for temporary files during DDL operations | |
Generate trace output in the log for each call to the SstFileWriter | |
DBOptions::two_ | |
Allowing statement based binary logging which may break consistency | |
Option updates per column family for RocksDB | |
DBOptions::use_ | |
Use ClockCache instead of default LRUCache for RocksDB | |
DBOptions::use_ | |
DBOptions::use_ | |
DBOptions::use_ | |
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 | |
Verify checksums when reading index/table records | |
DBOptions::wal_ | |
DBOptions::wal_ | |
DBOptions::wal_ | |
DBOptions::WAL_ | |
DBOptions::WAL_ | |
BlockBasedTableOptions::whole_ | |
Maximum size of write batch in bytes. 0 means no limit. | |
WriteOptions::disableWAL for RocksDB | |
WriteOptions::ignore_ | |
DBOptions::write_ | |
The size of the buffers used [NOT] IN evaluation via partial matching | |
Disallow authentication for accounts that have old (pre-4.1) passwords | |
Limit LOAD DATA, SELECT ... OUTFILE, and LOAD_ | |
Specifies the set of events to monitor. Can be CONNECT, QUERY, TABLE, QUERY_ | |
Comma separated list of users to exclude from auditing | |
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 | |
Comma separated list of users to monitor | |
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 | |
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. For compatibility with MySQL defaults this variable should be set to "autocommit, character_ | |
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 withthe same characteristics (isolation level, read only/read write,snapshot - but not any work done / data modified within the transaction). | |
Enables use of shared memory for Servers running on Microsoft Windows | |
Base name for shared memory usage by Server running on Microsoft Windows | |
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 | |
If set when a transaction is written to the binlog, parallel apply of that transaction will be avoided on a slave where slave_ | |
Changes are logged into the binary log with the @@skip_ | |
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 and LOGGING. 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. | |
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 or elapsed lock wait timeout, before giving up and stopping | |
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 | |
Mode of auto increment | |
Number of first read records when background search is used | |
Mode of background search | |
Number of second read records when background search is used | |
Temporary table's engine for BKA | |
Mode of BKA for Spider | |
The type of temporary table name for bka | |
Index block size | |
Bulk insert size | |
The mode of bulk updating and deleting | |
Bulk update size | |
Read casually if it is possible | |
Connection recycle mode | |
Strict connection recycle | |
Return same error code until interval passes if connection is failed | |
Use mutex at connecting | |
Connect retry count | |
Connect retry interval | |
Wait timeout of connecting to remote server | |
Mode of cardinality confirmation at background | |
Interval of cardinality confirmation.(second) | |
Mode of cardinality confirmation | |
Cardinality synchronization in partitioned table | |
Type of cardinality calculation | |
Weight coefficient to calculate effectiveness of index from cardinality of column | |
The type of delete_ | |
Execute "REPLACE" and "INSERT IGNORE" on remote server and avoid duplicate check on local server | |
Send 'ORDER BY' and 'LIMIT' to remote server directly | |
dry access | |
Read error mode if error | |
Write error mode if error | |
Number of first read records | |
Force prepare, commit, rollback mode | |
Log query to remote server in general log | |
Initial sql string alloc size | |
Internal limit | |
Internal offset | |
Execute optimize to remote server | |
Execute optimize to remote server with local | |
Manage SQL_ | |
Unlock tables for using connections in sql | |
Use inner xa transaction | |
The type of internal_ | |
Action of inner xa and snapshot both using | |
Remote server transmission when lock tables is executed at local | |
Exchange select lock to lock tables | |
Log sql at logging result errors | |
Log error from remote server in error log | |
Use low memory mode when SQL(SELECT) internally issued to a remote server is executed and get a result list | |
Max columns for order by | |
Sprit read mode for multi range | |
Wait timeout of receiving data from remote server | |
Wait timeout of sending data to remote server | |
Ping interval at transaction start | |
The retrieval result from a remote server is acquired by acquisition one by one | |
Number of records in a page when acquisition one by one | |
Read only | |
Set remote access charset at connecting for improvement performance of connection if you know | |
Set autocommit mode at connecting for improvement performance of connection if you know | |
Set remote database at connecting for improvement performance of connection if you know | |
Set SQL_ | |
Set remote time_ | |
Set transaction isolation level at connecting for improvement performance of connection if you know | |
Reset sql string alloc after execute | |
Permit one to link same server's table | |
Number of second read records | |
The mode of using columns at select clause | |
Lock for select with update | |
Use offset and limit parameter in SQL for split_ | |
The limit value for semi_ | |
Table lock during execute a sql | |
Use different connection if semi_ | |
Take a transaction during execute a sql | |
Transaction isolation level during execute a sql | |
Skip generating internal default condition | |
Number of rows at a select | |
Mode of table state confirmation at background | |
Interval of table state confirmation.(second) | |
Mode of table state confirmation | |
Table state synchronization in partitioned table | |
XA support | |
Sync autocommit | |
Sync time_ | |
Sync transaction isolation level | |
Return same error code until interval passes if table init is failed | |
The interval time between bulk insert and next bulk insert at coping | |
The number of rows inserted with bulk insert of one time at coping | |
Number of rows for bulk inserting | |
Table loop mode if the number of tables in table list are less than the number of result sets | |
Use real table for temporary table list | |
Mutex count of table lock for Spider UDFs | |
Mutex count of table mon for Spider UDFs | |
When start trx with snapshot, it send to all connections | |
Use start transaction with consistent snapshot | |
Use default database | |
Execute flush logs to remote server | |
Use handler for reading | |
Remote server transmission existence when UDF is used at condition and "engine_ | |
Execute optimize to remote server with local | |
Use table charset for remote access | |
The version of Spider | |
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. | |
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. | |
The number of cached table definitions | |
The number of cached open tables | |
Maximum number of table cache instances | |
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 | |
Minimum number of threads in the thread pool used on Microsoft Windows | |
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. | |
Set the time for this client | |
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 | |
Version of the used SSL library | |
The number of seconds the server waits for activity on a connection before closing it | |
The number of errors, warnings, and notes that resulted from the last statement that generated messages | |
To automatically control the assignment of autoincrement variables | |
Setting this variable is equivalent to setting wsrep_ | |
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. | |
Certify tables with no primary key | |
Address to initially connect to cluster | |
Name for the cluster | |
To convert locking sessions into transactions | |
home directory for wsrep provider | |
DBUG options to provider library | |
To enable debug level logging | |
To desynchronize the node from the cluster | |
Permit read operations when the node is in a non-operational component | |
Enable a workaround to handle the cases where inserting a DEFAULT value into an auto-increment column could fail with duplicate key error | |
binlog format to take effect over user's choice | |
When wsrep_ | |
Automatically update the (joiner) node's wsrep_ | |
To commit LOAD DATA transaction after every 10K rows inserted | |
To log multi-master conflicts | |
Max number of rows in write set | |
Max write set size (bytes) | |
mysql replication group commit | |
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. | |
Client connection address | |
Name of this node. This name can be used in wsrep_ | |
Command to execute upon changes in node state or cluster membership | |
To enable wsrep replication | |
Method for Online Schema Upgrade | |
Wsrep patch version, for example wsrep_ | |
Path to replication provider library | |
Semicolon (;) separated list of wsrep options (see wsrep_ | |
Recover database state after crash and exit | |
Reject queries from client connections | |
To enable myisam replication | |
Should MariaDB slave be restarted automatically, when node joins back to cluster | |
Number of autocommit retries the node attempts | |
Should slave thread do foreign key constraint checks | |
Number of threads used in applying write-sets from the cluster | |
Should slave thread do secondary index uniqueness checks | |
Authentication for SST connection | |
preferred donor node for the SST | |
Rejects blocking client sessions while node acts as a donor to a blocking SST operation | |
State snapshot transfer method | |
Address where node is waiting for SST contact | |
global transaction position to start from | |
Bitmask to configure synchronization waits for causality checks on the cluster |
The following System Variables are not present in MariaDB Community Server 10.2.43 but are present in one or more older 10.2 CS versions. Click on an item to see its details, including when it was removed.
Variable | Description |
|---|---|
DEPRECATED. This option may be removed in future releases, together with the option innodb_ | |
Background commit interval in seconds | |
Disable row lock when direct access InnoDB through InnoDB APIs | |
Enable binlog for applications direct access InnoDB through InnoDB APIs | |
Enable MDL for applications direct access InnoDB through InnoDB APIs | |
InnoDB API transaction isolation level | |
Use NUMA interleave memory policy to allocate InnoDB buffer pool | |
Simulate compression failures | |
DEPRECATED. This option may be removed in future releases, together with the InnoDB's internal memory allocator. Use OS memory allocator instead of InnoDB's internal memory allocator | |
turns on background syncs for RocksDB | |
DBOptions::base_ | |
DBOptions::concurrent_ | |
Forces memtable flush on ANALZYE table to get accurate cardinality | |
DBOptions::max_ | |
DBOptions::max_ | |
List of tables that will use read-free replication on the slave (i.e., not lookup a row during replication) | |
DBOptions::use_ | |
Auxiliary info | |
Allow only standards compiant CTE |
To see system variables supported in other versions, see "System Variables by MariaDB Server Version".