SQL Server - DBCC Commands

Command Name	Description
DBCC Cachestats	displays information about the objects currently in the buffer cache, such as hit rates, compiled objects and plans, etc.
DBCC DROPCLEANBUFFERS	Used to remove the clean buffers from the buffer cache, but it will not clear the dirty pages that are occupied in the memory
DBCC Errorlog	Used to recycle the errorlog file. Sp_cycle_errorlog also serves the same work
DBCC FlushProcINDB (@DBID)	Used to clear out the stored procedure cache for a specific database on a SQL Server, not the entire SQL Server
DBCC PROCCACHE	Displays information about how the stored procedure cache is being used
DBCC FREEPROCCACHE	Used to clear out the stored procedure cache for all SQL Server databases
DBCC MEMORYSTATUS	Complete information about the SQL Server Memory Cache
DBCC OPENTRAN	Shows the open transaction information
DBCC PINTABLE (@db_id,@tbl_id)	table associated with this database will be PINNED in the physical RAM to increase the performance by decreasing the disk I/O. This should be done by thorough command on the memory concept
DBCC UNPINTABLE (@db_id,@tbl_id)	Table associated with this database will be UNPINNED in the physical RAM to give room to other resources for using the RAM. This should be done by thorough command on the memory concept
DBCC SHOWCONTIG (@Table_id, @IndexID)	to find the fragmentation level of the table
DBCC SHOW_STATISTICS (@table_name, @index_name)	Selectivity of the index used.
DBCC SQLPERF(Logspace)	Gives the LOG FILE information likes usage, %occupied
DBCC SQLPERF(WAITSTATS)	WAITSTATS information will be provided
DBCC SQLPERF(IOSTATS)	Provides read write outstanding information
DBCC SQLPERF(RASTATS)	Provides read ahead outstanding information
DBCC SQLPERF(THREADS)	Provides threads information, mem usage and CPU usage
DBCC UPDATEUSAGE('database_name')	Updates the space usage information of the objects after the any heavy operations like reorg/rebuild index has happened