This week, Microsoft released two pretty big updates.
SQL Server 2016 SP2 CU7 has a ton of fixes including:
- Filtered index corruption
- Access violations in sys.dm_exec_query_statistics_xml, sys.dm_hadr_availability_replica_states, sys.availability_replicas, sys.dm_db_xtp_hash_index_stats, sys.fn_dump_dblog, sys.dm_db_xtp_checkpoint_files (translation: if you monitor your servers, you should probably apply this CU to avoid problems caused by the monitoring tool’s queries)
- AG failover fails
- Incorrect query results on columnstore indexes, and also this
SQL Server 2017 CU 15 has even MORE fixes, and you owe it to yourself to read the full list.
There are some CUs you might be tempted to skip because they don’t affect you. I don’t think this week’s releases fall into that category – there are a wide, wide range of features affected by this week’s patches.
Update May 28: CU15 introduced a bug in Availability Groups. Queries of sys.fn_hadr_backup_is_preferred_replica will fail, which can cause your backups not to work. The workaround is to do your backups with another method (like manually calling the backup commands rather than using maintenance plans or Ola Hallengren’s scripts), or avoid CU15.