System Variables for MariaDB Enterprise ColumnStore 1.4
This page is part of MariaDB's Documentation.
The parent of this page is: Reference for MariaDB Enterprise ColumnStore 1.4
Topics on this page:
Overview
MariaDB Enterprise ColumnStore 1.4 can be configured using system variables.
Reference material is available for MariaDB Enterprise ColumnStore 1.4.
MariaDB Enterprise ColumnStore 1.4 is included with 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]
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_
$ 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 10.4 supports many system variables. When MariaDB Enterprise ColumnStore 1.4 is deployed with MariaDB Enterprise Server 10.4, it adds several system variables of its own. The system variables implemented by Enterprise ColumnStore 1.4 have the columnstore_
prefix. However, the behavior of Enterprise ColumnStore 1.4 can also be affected by some standard system variables implemented by ES 10.4.
System Variables for MariaDB Enterprise ColumnStore 1.4
Variable | Description |
---|
The following System Variables are not present in MariaDB Enterprise ColumnStore 1.4.4 but are present in one or more older 1.4 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 |
To see system variables supported in other versions, see "System Variables by MariaDB Enterprise ColumnStore Version".
System Variables for MariaDB Enterprise Server 10.4
Since MariaDB Enterprise ColumnStore 1.4 integrates with MariaDB Enterprise Server 10.4, some of the System Variables for MariaDB Enterprise Server 10.4 also apply to MariaDB Enterprise ColumnStore 1.4.