Re: [SQL] JOIN index/sequential select problem

On Wed, 12 May 1999, Tom Lane wrote:
> I'm guessing you might be compiling with LOCALE support turned on?

Unfortunately not.  I run ./configure --prefix=/home/postgres so that
wouldn't be the case.

> The parser's hack to make LIKE comparisons indexable is only half
> functional in that case, since you get the >= comparison but not the <=
> one.  Given the small size of your tables, the optimizer is probably
> estimating that an index scan isn't going to be selective enough to
> justify its extra cost.

Then postgres is not guessing right.  Even tho the table only has 
~200 rows, the query still takes forever to finish.  I have let it go for
a few minutes, and it still wasn't done..  I suppose that would be because
it's doing a seq scan on the inventorysuppliers table for EACH hit in the
av_parts table.  That's bound to be slow :)

> FWIW, I do get an index scan plan on an attempt to duplicate this
> case... but I'm not using LOCALE.

Weird.  I'll have to look at it more.

Thanks,
Ole Gjerde