SET GLOBAL
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Sets an engine variable globally.
SET GLOBAL can be used to set two types of variables listed below.
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Global: When you set a global variable, its value is effective for your current connection to the node and any subsequent connections, initiated by any user.
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Session that can also be set globally: When you set this type of variable globally, its value is NOT effective for your current connection to the node but is effective for any subsequent connections to the node, initiated by any user.
Most variables have global scope.session that can also be set globally
are indicated in the Description
column in the Sync Variables Lists and Non-Sync Variables List.
To set a sync variable, you can use SET CLUSTER instead of SET GLOBAL.
See the engine variables overview for more information on engine variables.
Syntax
SET GLOBAL variable_name = value
SET @@GLOBAL.variable_name = valueRemarks
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variable_is the name of a global engine variable.name -
The
@@global.syntax for engine variables is supported for compatibility with some other database systems.variable_ name This is similar to MySQL behavior. -
When you run SET GLOBAL to set a session variable globally, you need to additionally run FLUSH CONNECTION POOLS on every aggregator and restart the SQL session for the new session variable value to take effect.
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Refer to the Permission Matrix for the required permission.
Example
The following example sets a global variable and retrieves its value.
Set the variable:
SET GLOBAL connect_timeout = 15;
Retrieve its value:
SELECT @@connect_timeout;
Refer Assigning Expressions to Variables for more examples.
Related Topics
Last modified: March 21, 2024