New SQL Server 2019 CU9, 2016 SP2 CU 16

Late last year, Microsoft announced that they were going to hold off on patches for a while due to the pandemic and the holidays.

Incorrect results bugs:

• Incorrect query results from the CONCAT function
• Incorrect results from in-memory optimized tables with clustered columnstore indexes (this one’s only got 2016 in the KB, not 2019 – it’s not clear whether 2019 was unaffected, or just not patched)
• Incorrect results on linked server queries with aggregates or joins on a remote table with a filtered index
• Incorrect results for inserting data into memory-optimized tables and UDFs
• More fixes for inlined scalar functions – out of memory errors, access violations, and non-yielding scheduler errors. They didn’t add any new situations where they stop the function from inlining, though, so that’s good.
• Incorrect data mask applied for queries with UDFs
• Incorrect results between in-memory optimized tables and disk-based tables – no notes on this one, so guessing it’s super-rare or super-embarrassing or both

Other bugs:

• If you have columnstore trace flags 876, 11064, and 11068 turned on, you may end up with single-row rowgroups
• MERGE statement fails (OMG, they’re finally fixing bugs in the MERGE statement)
• Rollback never finishes if there’s an XE session present for sql_transaction events
• Severe spinlock contention – this one was also reported in 2019 CU8, so apparently more work has been done
• Improves Query Store scalability for ad-hoc workloads
• Memory leak when auditing is turned on

There are also a LOT of fixes for Availability Groups and external queries, like Big Data Clusters and querying Oracle.

Go get ’em! Here’s 2016 SP2 CU16 and 2019 CU9. It’s been 5 months since 2017 was updated, too, so I wouldn’t be surprised to see 2017 CU23 drop sometime soon.