Question

Assuming that I have the following T-SQL code:

SELECT * FROM Foo f
INNER JOIN Bar b ON b.BarId = f.BarId;
WHERE b.IsApproved = 1;

The following one also returns the same set of rows:

SELECT * FROM Foo f
INNER JOIN Bar b ON (b.IsApproved = 1) AND (b.BarId = f.BarId);

This might not be the best case sample here but is there any performance difference between these two?

Answer 1

No, the query optimizer is smart enough to choose the same execution plan for both examples.

You can use SHOWPLAN to check the execution plan.

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Nevertheless, you should put all join connection on the ON clause and all the restrictions on the WHERE clause.