Re: planer picks a bad plan (seq-scan instead of index) - Mailing list pgsql-general

> Try putting your conditions as part of the join:
> SELECT * FROM shop.dvds
> LEFT JOIN
>   oldtables.movies
> ON
>   mov_id = dvd_mov_id
>   AND (
>     lower(mov_name) LIKE '%superman re%'
>     OR lower(dvd_name) like '%superman re%'
>     OR lower(dvd_edition) LIKE '%superman re%'
>   )
> LEFT JOIN shop.data_soundmedia ON sm_info_ean = dvd_ean
>


unfortunately its getting optimized into the same plan :-)


> I'd also be tempted to look at a tsearch2 setup for the word searches.


tsearch2 doesn't work that well for exact matches (including special chars).
but the culprit here isn't the '%...'%' seqscan, but rather the additional
joined table (where no lookup except for the join-column takes place) that
makes the query going from 200ms to 24sec.

regards,
thomas