DBCC FREESYSTEMCACHE

Release all unused cache entries from all caches.

Syntax
      DBCC FREESYSTEMCACHE
        ('ALL' [ , pool_name ] ) 
           [WITH  [MARK_IN_USE_FOR_REMOVAL] , [NO_INFOMSGS]  ]

Key:
    ALL                     - All supported caches.

    MARK_IN_USE_FOR_REMOVAL - Free up currently used cache entries asap (asynchronous).
                              After the DBCC FREESYSTEMCACHE WITH MARK_IN_USE_FOR_REMOVAL runs,
                              new entries created in the cache aren't affected.

    NO_INFOMSGS             - Suppress all information messages.

    pool_name               - Specifies a resource governor pool cache.
                              Only entries associated with this pool are freed.

To list the available pool names, run: SQL SELECT name FROM sys.dm_resource_governor_resource_pools;

MARK_IN_USE_FOR_REMOVAL will not prevent new entries being created in the cache.
Requires ALTER SERVER STATE permission on the server.

Examples

Release unused cache entries from a Resource Governor pool cache:

-- Clean all the caches with entries specific to the
-- resource pool named "default".
DBCC FREESYSTEMCACHE ('ALL', [default]);

Release entries from their respective caches after they become unused:

DBCC FREESYSTEMCACHE ('ALL') WITH MARK_IN_USE_FOR_REMOVAL;

“It's hard to be funny when you have to be clean” ~ Mae West

Related commands

DBCC FREEPROCCACHE - Remove items from plan cache.
DBCC FREESESSIONCACHE - Flush the distributed query connection cache.