mcsSetConfig for MariaDB Enterprise ColumnStore

Overview

MariaDB Enterprise ColumnStore includes the mcsSetConfig utility, which sets configuration parameters in Columnstore.xml.

Reference material is available for MariaDB Enterprise ColumnStore.

MariaDB Enterprise ColumnStore is included with MariaDB Enterprise Server.

USAGE

The syntax for the mcsSetConfig utility is:

$ mcsSetConfig [OPTION ...] SECTION PARAMETER VALUE

The supported sections and parameters are shown in Columnstore.xml, which is located in /etc/columnstore/ by default.

With multi-node MariaDB Enterprise ColumnStore, the mcsSetConfig utility should be executed on the primary server.

Note

Please do not change ColumnStore configuration parameters in Columnstore.xml unless you have been directed to make the change by MariaDB Engineering or the documentation. Incorrect settings can render your system unusable. If you have any questions about ColumnStore configuration, please contact MariaDB Support.

DETAILS

The mcsSetConfig utility sets configuration parameters in Columnstore.xml, which is located in /etc/columnstore/ by default.

When most configuration parameters in Columnstore.xml are changed, ColumnStore must be restarted for the changes to take effect.

mcsGetConfig is a related utility that gets configuration parameters from Columnstore.xml.

EXAMPLES

Set Mandatory Utility User Account

To set the configuration parameters for the mandatory utility user account in Columnstore.xml:

$ sudo mcsSetConfig CrossEngineSupport Host 127.0.0.1
$ sudo mcsSetConfig CrossEngineSupport Port 3306
$ sudo mcsSetConfig CrossEngineSupport User cross_engine
$ sudo mcsSetConfig CrossEngineSupport Password cross_engine_passwd

When these configuration parameters are updated in Columnstore.xml, ColumnStore must be restarted for the changes to take effect.

Set Memory Limit for Joins

To set the memory limit for joins in Columnstore.xml:

$ mcsSetConfig HashJoin PmMaxMemorySmallSide 1GB

When this configuration parameter is updated in Columnstore.xml, ColumnStore must be restarted for the changes to take effect.

This configuration parameter can be changed for a specific session without restarting ColumnStore by calling the mcssetparms() function:

SELECT mcssetparms("pmmaxmemorysmallside", "1000000");

Set Disk-Based Join Configuration

To set the configuration parameters for disk-based joins in Columnstore.xml:

$ mcsSetConfig HashJoin AllowDiskBasedJoin Y
$ mcsSetConfig HashJoin TempFileCompression Y
$ mcsSetConfig HashJoin TempFilePath /mariadb/tmp

When these configuration parameters are updated in Columnstore.xml, ColumnStore must be restarted for the changes to take effect.

Post-Change Restart

When most configuration parameters in Columnstore.xml are changed, ColumnStore must be restarted for the changes to take effect.

For single-node ColumnStore, restart ColumnStore's systemd service:

$ sudo systemctl restart mariadb-columnstore

For multi-node ColumnStore, restart the ColumnStore cluster using the mcs utility:

$ mcs cluster restart