KB4056955 - FIX: Queries that cast string or binary data to XML take a long time to compile in SQL Server 2016 and 2017

Applies To
SQL Server 2016 Service Pack 1 SQL Server 2016 Developer - duplicate (do not use) SQL Server 2016 Enterprise - duplicate (do not use) SQL Server 2016 Enterprise Core - duplicate (do not use) SQL Server 2016 Standard - duplicate (do not use) SQL Server 2017 on Windows (all editions) SQL Server 2017 on Linux (all editions)

Symptoms

Assume that you run a query that casts string or binary data to Extended Markup Language (XML) datatype in Microsoft SQL Server 2016 and 2017. You may notice that the compilation time taken by the query might be much longer when compared to the compilation time taken in the earlier versions of SQL Server.

Resolution

This issue is fixed in the following cumulative updates for SQL Server:

Cumulative Update 4 for SQL Server 2017

Cumulative Update 7 for SQL Server 2016 SP1

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:

Latest cumulative update for SQL Server 2017

Latest cumulative update for SQL Server 2016

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.