Symptoms
In Microsoft SQL Server 2019, when you run a query such as SELECT MAX(LEN(MAPKEY)) FROM <TableName> OPTION(MAXDOP 1) in which the MAPKEY value is a computed column, the following assertion occurs:
Msg 3624, Level 20, State 1, Line <LineNumber>
A system assertion check has failed. Check the SQL Server error log for details. Typically, an assertion failure is caused by a software bug or data corruption. To check for database corruption, consider running DBCC CHECKDB. If you agree to send dumps to Microsoft during setup, a mini dump will be sent to Microsoft. An update might be available from Microsoft in the latest Service Pack or in a Hotfix from Technical Support.
Msg 596, Level 21, State 1, Line <LineNumber>
Cannot continue the execution because the session is in the kill state.
Msg 0, Level 20, State 0, Line <LineNumber>
A severe error occurred on the current command. The results, if any, should be discarded.
Note This problem occurs because the plan that's generated for the query contains a Compute Scalar operator that operates on computed, temporary lobs with batch mode.
Resolution
Cumulative update information
This problem is fixed in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for your version of SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.