Slow SQL Server performance and a memory leak after you apply Cumulative Update 3 for SQL Server 2012 Service Pack 1 or in SQL Server 2014

Applies to: SQL Server 2012 EnterpriseSQL Server 2014 EnterpriseSQL Server 2014 Enterprise

Symptoms


After you apply Cumulative Update 3 for Microsoft SQL Server 2012 Service Pack 1 to an instance of SQL Server or in SQL Server 2014, SQL Server performance might be slow, and a memory leak might occur.

If you run the following query when this problem occurs, you see that the Mem in MB value and the row count value keep increasing for the MEMOBJ_COMPILE_ADHOC memory object:

select type, sum(pages_in_bytes)/1024.0/1024.00 'Mem in MB', count (*) 'row count' from sys.dm_os_memory_objects
where type like '%MEMOBJ_COMPILE_ADHOC%'
group by type

Notes
  • The DBCC FREEPROCCACHE command does not help reduce the Mem in MB value.
  • This problem only occurs when you run many sp_prepare procedures to prepare parameterized Transact-SQL statements.

Resolution


The issue was first fixed in the following cumulative update of SQL Server.

Cumulative Update 1 for SQL Server 2014

Cumulative Update 7 for SQL Server 2012 SP1

Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References


See the terminology that Microsoft uses to describe software updates.