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From:Michael Widenius Date:November 3 2001 3:11am
Subject:Re: Possible bug in self-join order optimization
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Hi!

>>>>> "Eric" == Eric  <ej@stripped> writes:

Eric> They are basically doing this one type of query...with some
Eric> modifications on the WHERE clauses for each of the joins.  i.e. some
Eric> queries do ranges on the nvalue, some do constant matches.

Eric> The WHERE clauses for each of the joins is different, but it involves
Eric> the same keys and most often is of the type:  type=constant, nvalue <
Eric> x, nvalue > y.  The problem is actually quite specific in that MySQL
Eric> doesn't estimate the number of rows coming from the join based on the
Eric> range, only based on the constant, which is what I want to improve
Eric> upon.

Eric> Assuming you agree with my statements here, I will begin investigating
Eric> the necessary coding as there seems to have been enough verification
Eric> that what I think needs to be coded actually is necessary.  I will
Eric> send along questions as I have them.

This is fine.  Just send any questions to internals@stripped
and we will do our best to answer them!

Regards,
Monty
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