>Sergey,
>
>>It doesn't apply to EXISTS subqueries because SQL Server doesn't retrieve any data for them.
>
>That is not our experience based on examining the I/Os that occur. I'll see if I can come up with some examples against northwind later tonight.

Hi David,

It turned out that I was wrong. See EXISTS Subqueries: SELECT 1 vs. SELECT *
Quote: "The QP will take and expand all *'s early in the pipeline and bind them to objects (in this case, the list of columns). It will then remove unneeded columns due to the nature of the query."
Recomendation: Use something like "SELECT 1 ..."