Re: optimisation of outer join

On Thu, 09 Aug 2001, Stephan Szabo wrote:

> > depos=# explain select cdtitles.title, cdtitles.artist, song,
> > fk_products_id, p.title, p.artist from cdsongs, cdtitles left join
> > products p on (cdtitles.fk_products_id = p.id) where cdtitles.cdid =
> > cdsongs.cdid and song like 'mushroom festi%';
> > NOTICE:  QUERY PLAN:
>
> You're forcng the cdtitles cross products join first I believe here.
> I think you may want to force the other join first, so maybe...
>
> explain select s.title, s.artist, song, fk_products_id, p.title, p.artist
> from (cdsongs inner join cdtitles on (cdtitles.cdid=cdsongs.cdid)) s
>  left join products p on (s.fk_products_id = p.id) where song like
>  'mushroom festi%';

Fantastic, that works great ! Thanks :-)

 Nick

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