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Re: Performance impact of filtering in ON vs WHERE clause
Posted by: Sebastien Caisse
Date: May 02, 2006 01:06PM

I don't see you're point about using "USING". It just determines which columns are used for the reference. In fact your statement is wrong in MySQL 5.01 and above (and this according to the SQL:2003 standard). It's all written in the link you've provided yourself.

Though indeed the quoted material you have mentioned does state what you mention and does SEAM to imply it too. However it does NOT mention in any way that this is how the join optimization work.

The first example posted in this thread is a very valid optimization path (well at elast programmatically) and the question asked is still left unanswered.



Edited 1 time(s). Last edit at 05/02/2006 01:08PM by Sebastien Caisse.

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