DBCC Commands to Manage Cache in SQL Server

In SQL Server, there are several DBCC commands that can be used to manage the SQL Server buffer cache, plan cache, and other system caches. Here are some examples of commonly used DBCC commands:

DBCC FREEPROCCACHE: This command clears the plan cache, which is a portion of memory that stores execution plans for SQL Server queries. To clear the cache, simply execute the following command in a SQL Server query window:

DBCC FREEPROCCACHE;

DBCC FREESYSTEMCACHE: This command clears the specified system cache, such as the buffer cache, the procedure cache, or the service broker cache. To clear the buffer cache, for example, execute the following command:

DBCC FREESYSTEMCACHE('ALL');

This command clears all caches. You can also specify a specific cache to clear, such as the buffer cache or the procedure cache, by replacing 'ALL' with the appropriate cache name.

DBCC FREESESSIONCACHE: This command clears the cached cursors and temporary tables for a specific session. To clear the cache for the current session, execute the following command:

DBCC FREESESSIONCACHE;

DBCC DROPCLEANBUFFERS: This command clears the buffer cache for all databases on the SQL Server instance. This can be useful for testing purposes, but should not be used in a production environment. To clear the buffer cache, execute the following command:

DBCC DROPCLEANBUFFERS;

Note - These commands should be used with caution, as they can have a significant impact on SQL Server performance. It is recommended to only use them when necessary and to monitor performance after executing them.