Symptoms
Assume that you run some complex Data Analysis Expressions (DAX) queries in Microsoft SQL Server 2012 Analysis Services (SSAS 2012). When a scheduled data update starts while you run the queries, SSAS 2012 freezes.
Note This issue is resolved when you restart SSAS 2012.Cause
The issue occurs because all the threads in SSAS 2012 are building DAX Query Plan event text. Therefore, the time that is required to run the queries increases exponentially.
Resolution
Cumulative update information
Cumulative Update 7 for SQL Server 2012
The fix for this issue was first released in Cumulative Update 7. For more information about how to obtain this cumulative update package for SQL Server 2012, click the following article number to view the article in the Microsoft Knowledge Base:
2823247 Cumulative update package 7 for SQL Server 2012Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2012 fix release. We recommend that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2692828 The SQL Server 2012 builds that were released after SQL Server 2012 was released
Cumulative update 3 for SQL Server 2012 Service SP1
The fix for this issue was first released in Cumulative Update 3. For more information about how to obtain this cumulative update package for SQL Server 2012 SP1, click the following article number to view the article in the Microsoft Knowledge Base:
2812412 Cumulative update package 3 for SQL Server 2012 Service Pack 1Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2012 SP1 fix release. We recommend that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2772858 The SQL Server 2012 builds that were released after SQL Server 2012 Service Pack 1 was released
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.