SQL Server 2019 Cumulative Update 6: Important Fixes with Limited Documentation

Microsoft has released the 6th cumulative update for SQL Server 2019, and it’s a significant update. However, like the previous update, Microsoft has decided not to document much of the included bug fixes, leaving users with “bug reference numbers” that correspond to internal documentation that’s not available to the public. This approach can be problematic for businesses that rely on SQL Server for their database management needs.

Despite the lack of documentation, the update includes several important bug fixes that address issues reported by users. These fixes include issues related to unexpected results for variables when using multiple variable assignments from select statements with scalar UDF inlining, high CPU consumption on Availability Group secondary databases, access violation exceptions when auditing commands that require password masking, and errors that occur in SCOM 2019 when upgrading from SQL Server 2016 or 2017 to SQL Server 2019 CU5 with UDF inlining on.

There have also been improvements made to XML validation in SSIS XML Tasks, allowing for validation of included schemas in XML tasks. Additionally, fixes have been made for an access violation error that occurs when plan cache involves sys.dm_hadr_ag_threads and sys.dm_hadr_db_threads DMVs and an issue with an orphaned spinlock due to access violation that results in repeatedly printed messages in the log.

While the lack of documentation is concerning, SQL Server users should still consider installing Cumulative Update 6 to benefit from the latest fixes and improvements. As always, it’s important to carefully review the release notes and any available KB articles (https://support.microsoft.com/en-us/topic/kb5005106-cumulative-update-6-for-sql-server-2019-6f5088d4-4f20-4e2a-a1c4-1fa66cb65a20) to understand the changes included in the update and determine the best course of action for your specific environment.

Overall, while the lack of documentation is frustrating, Cumulative Update 6 for SQL Server 2019 includes several important fixes and improvements that should not be ignored. With the community keeping an eye out for any issues, any potential problems should be identified quickly, ensuring a smooth update process.