Continuing my series of articles on latches, this time I’m going to discuss the DBCC_OBJECT_METADATA latch and show how it can be a major bottleneck for consistency checks prior to SQL Server 2016 under certain circumstances. The issue affects DBCC CHECKDB, DBCC CHECKTABLE, and DBCC CHECKFILEGROUP, but for clarity I’ll just reference DBCC CHECKDB for the rest of this post.
You might wonder why I’m writing about an issue that affects older versions, but there are still a huge number of SQL Server 2014 and older instances out there, so it’s a valid topic for my series.
Read on to understand what
DBCC_OBJECT_METADATA does and how it can become a bottleneck on those older versions of SQL Server.