Microsoft SQL Server DBCC DBCC maintenance commands
Example
DBCC commands enable user to maintain space in database, clean caches, shrink databases and tables.
Examples are:
DBCC DROPCLEANBUFFERS
Removes all clean buffers from the buffer pool, and columnstore objects from the columnstore object pool.
DBCC FREEPROCCACHE
-- or
DBCC FREEPROCCACHE (0x060006001ECA270EC0215D05000000000000000000000000);
Removes all SQL query in plan cache. Every new plan will be recompiled: You can specify plan handle, query handle to clean plans for the specific query plan or SQL statement.
DBCC FREESYSTEMCACHE ('ALL', myresourcepool);
-- or
DBCC FREESYSTEMCACHE;
Cleans all cached entries created by system. It can clean entries o=in all or some specified resource pool (myresourcepool in the example above)
DBCC FLUSHAUTHCACHE
Empties the database authentication cache containing information about logins and firewall rules.
DBCC SHRINKDATABASE (MyDB [, 10]);
Shrinks database MyDB to 10%. Second parameter is optional. You can use database id instead of name.
DBCC SHRINKFILE (DataFile1, 7);
Shrinks data file named DataFile1 in the current database. Target size is 7 MB (tis parameter is optional).
DBCC CLEANTABLE (AdventureWorks2012,'Production.Document', 0)
Reclaims a space from specified table
