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SQL Head Block not being released

Posted on 2010-08-13
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Last Modified: 2012-05-10
Experts,

First let me apologize if this has been asked before.

We have a database we are experiencing some major locking issues with.  We noticed some long wait times and a large number of waiting tasks.  Upon following the session IDs all the way back to the head blocking session ID that session ID is still marked as the head block, but has no SQL Command associated with it.  The only thing associated with the session is "SET TRANSACTION ISOLATION LEVEL READ COMMITTED"

Our web application is Cold Fusion Based hitting a SQL Server 2008 Server.

Please let me know where to look and what to look for.

Thanks in advance.
Chad
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Question by:cpence
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dwkor earned 500 total points
ID: 33434924
In 99% of the cases concurrency and blocking issues related with non-optimized queries. Take a look at the sql statements system is executing and see is plans are not optimal (table/index scans instead of seek).

As the temporary solution you can enable read committed snapshot mode on the database (http://technet.microsoft.com/en-us/library/bb522682.aspx). In this mode writers do not block readers. It introduces extra load to tempdb so check that it's on the fast drive
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