System Variables for MariaDB Enterprise ColumnStore

Overview

MariaDB Enterprise ColumnStore can be configured using system variables.

Reference material is available for MariaDB Enterprise ColumnStore.

MariaDB Enterprise ColumnStore is included with MariaDB Enterprise Server.

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]
columnstore_import_for_batchinsert_delimiter=44

Read All Values from Configuration Files

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

$ my_print_defaults --mysqld

Set on the Command-Line

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

$ mariadbd --columnstore_import_for_batchinsert_delimiter=44 [OPTION ...]

Set the Global Value Dynamically

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

SET GLOBAL columnstore_import_for_batchinsert_delimiter=44;

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 columnstore_import_for_batchinsert_delimiter=44;

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 'columnstore_%';

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

SHOW GLOBAL VARIABLES
   WHERE Variable_name IN(
      'columnstore_import_for_batchinsert_delimiter',
      'columnstore_import_for_batchinsert_enclosed_by'
   );

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.columnstore_import_for_batchinsert_delimiter,
   @@session.columnstore_import_for_batchinsert_enclosed_by;

DETAILS

MariaDB Enterprise Server supports many system variables. When MariaDB Enterprise ColumnStore is deployed with MariaDB Enterprise Server, it adds several system variables of its own. The system variables implemented by Enterprise ColumnStore have the columnstore_ prefix. However, the behavior of Enterprise ColumnStore can also be affected by some standard system variables implemented by ES.