[thelist] MySQL optimization
Steve Lewis
nepolon at worlddomination.net
Tue Sep 27 13:37:46 CDT 2005
Anthony Ettinger wrote:
>>Query:
>> select DISTINCT sectionid
>> from SectionMembers LEFT JOIN Sections ON
>> Sections.id=SectionMembers.sectionid
>> where Sections.instid = '%bindVal01%'
>>
>
> Have you defined indexes for the fields you're joining
> on?
Long answer: instid and sectionid are foreign keys, id is a primary key.
Short answer: Yes, all three are indexed.
Note:
It looks to me like I don't want a left join, I want an inner join - an
inner join should prune the result tree further before the where clause
is applied. That still doesn't remove my distinct clause, however. I'm
still looking for another optimization.
--
SteveL
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