Symptoms
Assume that you run a query that contains anti-join clauses on a complex join predicate, such as conjunction of inequalities. If you run this query in SQL Server 2014 Service Pack 1 (SP1) with a 4199 trace flag enabled, you experience poor performance because of a sub-optimal query plan.
Resolution
This issue is fixed in the following service pack for SQL Server:
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. Our recommendation is to apply the latest service pack and the latest cumulative update for that service pack. You do not have to install a previous service pack before you install the latest service pack. Use Table 1 in the following article for finding more information about the latest service pack and latest cumulative update.
How to determine the version, edition, and update level of SQL Server and its components
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.
