SQL 2016 – It Just Runs Faster: DBCC Scales 7x Better

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Many of you have experienced (MULTI_OBJECT_SCANNER* based) waits while running DBCC CHECKS*(checkdb, checktable, …)


Internally DBCC CHECK* uses a page scanning coordinator design (MultiObjectScanner.)  SQL Server 2016 changes the internal design to (CheckScanner), applying no lock semantics and a design similar to those used with In-Memory Optimized (Hekaton) objects, allowing DBCC operations to scale far better than previous releases.


MultiObjectScanner = Older design CheckScanner = New design

Note:  In addition to the no lock semantics the CheckScanner leverages advanced read-ahead capabilities.   The same read-ahead advancements are included in parallel scans of a heap.


‘It Just Runs