https://support.microsoft.com/en-us/help/4536648/cumulative-update-12-for-sql-server-2016-sp2

https://download.microsoft.com/download/6/0/6/606B3A2E-0EAE-4DCD-930D-178686370921/SQLServer2016-KB4536648-x64.exe

https://sqlserverupdates.com/news/announcing-sql-server-2016-sp2-cumulative-update-12/

Hundreds of thousands of years of humans roaming the earth.

Countless scientific discoveries. The wheel. The light bulb. Handerpants.

It’s all led up to this exact moment: SQL Server 2016 SP2 Cumulative Update 12. If, like me, you like SQL Server to keep running, then you’ll probably want to pay attention:

• SQL Server can shut down when you hit the max number of sessions
  
• SQL Server can shut down due to lock conflicts during error message processing
  
• “SQL Server crashes frequently” when you check a clustered columnstore index for corruption
  
• AGs may have “interruption” – I’m guessing that means the AG stops replicating, but it’s not clear from the KB article. This particular article wins this CU’s prize for The Vaguest And Most Dangerous Article. Congratulations!
  
• Stack dumps when transaction replication has a heavy workload on the publication database
  
• Stack dumps when you query persisted computed columns
  
• Stack dumps when you run a batch mode query with multiple joins (that’s columnstore indexes in 2016)
  
• Scalar functions run slower than they did on SQL Server 2008 R2
  
• Non-yielding scheduler when the primary AG replica runs low on memory
  
• AG may think there’s a missing log block when the database isn’t very active
  
• AG automatic seeding may fail
  
• AGs with persistent log buffers: “all of the secondaries in the AG become unavailable”
  
• Change tracking auto cleanup causes access violations and stack dumps
  
• Access violations when Extended Events tries to capture query text on busy servers
  
• Error when stored proc in database A pulls data from database B while being audited in database C
  
• Stack dumps when you alter database-scoped configurations
  
• Incorrect statistics histograms when they’re updated in parallel – which also means that after you apply this CU, you should probably update your statistics.
  

There’s also a new feature: the default system health Extended Events session can store way more data now, AND you can edit how much it holds!

Lots of good stuff in there. All of human evolution has been poised for this moment. Now is your time to shine: go get ’em.

Brent Ozar