Clearing cache and buffer

clear_memory_cache.sql

-- releases all unused cache entries from all caches
DBCC FREESYSTEMCACHE('All') WITH NO_INFOMSGS;

-- flushes the distributed query connection cache used by distributed queries against an instance
DBCC FREESESSIONCACHE WITH NO_INFOMSGS;         

-- manually removes a single plan or all plans from the cache
DBCC FREEPROCCACHE WITH NO_INFOMSGS;

-- clear the data buffer
DBCC DROPCLEANBUFFERS WITH NO_INFOMSGS;

-- resets the wait statistics data that your SQL Server has collected since it was last restarted
DBCC SQLPERF('sys.dm_os_wait_stats' , CLEAR)