This may be the typical situation within your database environment where the you might have killed a SPID (Process) that has been running for long time, without knowing the ROLLBACK operations for such processes. Say if you are executing a stored procedure which is built with a transactional based statements, by default the relational engine has the ability to control transactions mainly when you have specified a transaction starts and ends. In addition to that it must also be able to correctly handle...(
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Read the complete post at http://sqlserver-qa.net/blogs/perftune/archive/2008/05/06/4120.aspx