Why "EXISTS" is more efficient than "IN" in SQL Server 2000 / 2005 !!

Posted on 2007-07-21
Medium Priority
Last Modified: 2010-03-20

Can you please explain me why "EXISTS" is more efficient than "IN" in SQL Server 2000 / 2005 ? Please explain me in simple terms with simple examples.

Appreciate your time and patience !!

Question by:kishore_peddi
1 Comment
LVL 143

Accepted Solution

Guy Hengel [angelIII / a3] earned 2000 total points
ID: 19541871
EXISTS can (and will) stop the subselect on the first match, while IN has to get the complete list of the subselect first, and then do the match.

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