IN vs. JOIN with large rowsets

Question

I\'m wanting to select rows in a table where the primary key is in another table. I\'m not sure if I should use a JOIN or the IN operator in SQL Server 2005. Is there any si

Answer 1

The IN is evaluated (and the select from b re-run) for each row in a, whereas the JOIN is optimized to use indices and other neat paging tricks...

In most cases, though, the optimizer would likely be able to construct a JOIN out of a correlated subquery and end up with the same execution plan anyway.

Edit: Kindly read the comments below for further... discussion about the validity of this answer, and the actual answer to the OP's question. =)