Entity Framework 4.2 exec sp_executesql does not use indexes (parameter sniffing)

Question

I\'m encountering some major performance problems with simple SQL queries generated by the Entity Framework (4.2) running against SQL Server 2008 R2. In some situations (but

Answer 1

At this point I would recommend:

---

Set the optimize for ad hoc workloads setting to true.

EXEC sp_configure 'show advanced', 1;
GO
RECONFIGURE WITH OVERRIDE;
GO
EXEC sp_configure 'optimize for ad hoc', 1;
GO
RECONFIGURE WITH OVERRIDE
GO
EXEC sp_configure 'show advanced', 0;
GO
RECONFIGURE WITH OVERRIDE;
GO

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If after some time this setting doesn't seem to have helped, only then would I try the additional support of the trace flag. These are usually reserved as a last resort. Set the trace flag using the command line via SQL Server Configuration Manager, as opposed to in a query window and using the global flag. See http://msdn.microsoft.com/en-us/library/ms187329.aspx