Symptoms
Assume that you use SQL Server 2019 with PolyBase feature installed. You may notice that a PolyBase query (against external tables) may hang in the situation where the Data Management software (DMS) service is in the process of restarting when the query is issued.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative update for SQL Server:
About
cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Workaround
To work around the issue, you can restart SQL Server on Big Data Cluster (BDC). On Windows system, you can just restart the PolyBase services.
References
Learn about the terminology that Microsoft uses to describe software updates.
