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
- 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.