http://sqlinthewild.co.za/index.php/2010/02/18/not-exists-vs-not-in/
http://sqlinthewild.co.za/index.php/2010/03/23/left-outer-join-vs-not-exists/
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability