Symptoms
Assume that you run a query in Microsoft SQL Server 2014. The query contains table joins, and the related table has a Clustered Columnstore Index (CCI). In this situation, comparing to the earlier version of SQL Server, you may experience poor query performance because of missing CCI segment elimination.
Cause
This issue occurs because of a regression in SQL Server 2014. During a probe scan of a hash join, SQL Server does not use available information (bloom filter bitmap) to eliminate CCI segments.
Resolution
The issue was first fixed in the following cumulative update of SQL Server.
Cumulative Update 1 for SQL Server 2014 SP1 /en-us/help/3067839
Cumulative Update 8 for SQL Server 2014 /en-us/help/3067836
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:
Hotfix information
Hotfix for SQL Server 2014This hotfix is included in the following hotfix package:
KB 3058512: FIX: Unpivot Transformation task changes NULL to NULL or empty strings in SSIS 2014
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
