DBCC FREEPROCCACHE (Transact-SQL)
Removes all elements from the procedure cache.
Transact-SQL Syntax Conventions
Use DBCC FREEPROCCACHE to clear the procedure cache. Freeing the procedure cache causes, for example, an ad hoc SQL statement to be recompiled instead of reused from the cache. This can cause a sudden, temporary decrease in query performance. In SQL Server 2005 Service Pack 2, for each cleared cachstore in the plan cache, the SQL Server error log will contain the following informational message: "SQL Server has encountered %d occurrence(s) of cachestore flush for the '%s' cachestore (part of plan cache) due to 'DBCC FREEPROCCACHE' or 'DBCC FREESYSTEMCACHE' operations." This message is logged every five minutes as long as the cache is flushed within that time interval.