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.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 3170043 - Last Review: Jul 11, 2016 - Revision: 1
Microsoft SQL Server 2014 Service Pack 1