Re: Problems with index-scan on regexp in 8.1

On Mon, Nov 07, 2005 at 07:50:20AM +0100, Lars Kanis wrote:
> We're using Postgres 8.0.2 on SuSE10.0 (64-Bit). Tests on 8.1 beta 4 have
> shown no problems but this one:
>
>   SELECT * FROM mitglieder WHERE lower(vorname::text)='lars'
>
> does a bitmap-index-scan like this:

Check your locales. For non-ASCII locales the normal shortcuts for
regex optimisation can't apply. Evidently your old installation uses a
different locale from your new one.

You should be able to make this work by declaring your index with
"text_pattern_ops", like so:

CREATE INDEX myindex ON mytable(mycolumn text_pattern_ops);

Hope this helps,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.