System Variables for MariaDB Enterprise Server

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;

System Variables by MariaDB Server Version

Choose a version of MariaDB Enterprise Server to see the system variables supported by that version:

Summary of System Variables