From: | "Daniel Cristian Cruz" <danielcristian(at)gmail(dot)com> |
---|---|
To: | "Drew Wilson" <drewmwilson(at)gmail(dot)com> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Many to many join seems slow? |
Date: | 2007-05-15 16:00:29 |
Message-ID: | 48d0cacb0705150900o29f11b42t5dc5634be50e496a@mail.gmail.com |
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Lists: | pgsql-performance |
2007/5/15, Drew Wilson <drewmwilson(at)gmail(dot)com>:
> =# explain SELECT s.source_id, s.value AS sourceValue, t.value AS
> translationValue
> FROM
> source s,
> translation_pair tp,
> translation t,
> language l
> WHERE
> s.source_id = tp.source_id
> AND tp.translation_id = t.translation_id
> AND t.language_id = l.language_id
> AND l.name = 'French' ;
>
> QUERY PLAN
> ------------------------------------------------------------------------
> -----------------------------------------------------
> Merge Join (cost=524224.49..732216.29 rows=92447 width=97)
This way you get all word matches for the French language. Shouldn't
it be all matches for a specific word (s.value = 'word' in WHERE)?
--
Daniel Cristian Cruz
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