KB4040014 - FIX: Query that joins a view and contains UNION ALL slow in SQL Server 2016

Symptoms

Consider the following scenario:

• You create a view that uses a UNION ALL operation to combine the results that are retrieved from multiple tables.

• You execute a query in batch mode that joins the view with other tables.

In this scenario, the query might run slowly.

Resolution

This fix is included in Cumulative Update 5 for SQL Server 2016 Service Pack 1.

Note After you install this update, you must enable the Query Optimizer hotfix. For more information about Query Optimizer hotfixes and Trace flags, see the following:

SQL Server Query Optimizer hotfix TF 4199 servicing model

DBCC console commands and Trace flags

About SQL Server 2016 builds

Each new build for SQL Server 2016 contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build 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 Microsoft uses to describe software updates.