Re: like and optimization

On Sun, 21 Jan 2001 00:25:17 +0000 (UTC), Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>Juriy Goloveshkin <juriy(at)avias(dot)com> writes:
>> Hello, I didn't know pgsql-sources close,
>> so I wrote this code just as example of idea.
>> Can somebody review and make patch for pgsql?
>
>AFAICT this only deals with the issue of single-byte characters that
>sort in an order different from their numeric order. The existing
>make_greater_string() code already deals with that case. Where it
>falls down is cases where sorting is context-dependent (multi-pass
>sort rules, digraphs, things like that). But I don't see anything
>here that would make such cases work.
>
>If you're trying to tell us that the 7.0.* code works correctly for
>KOI8-R locale, we'd be glad to re-enable LIKE optimization for that
>locale ...

Hello,

I have no knowledge of postgres internals at all (yet !), and I'm not
quite sure what this thread is exactly about.

But if anybody thinks that selects with LIKE on indexed columns with
single-byte non-ASCII characters are working OK: they are not !! See my
posting and following thread "7.0.3 reproduceable serious select error"
from a couple of days ago.

I made a reproduceable example of things going wrong with a "en_US"
locale which is the widely-used (single-byte) ISO-8859-1 Latin 1 charset.

Please excuse me if this has nothing to do with what you are talking
about. I'm just very eager to get rid of this (for our application)
extremely nasty bug !

friendly greetings,
Rob van Nieuwkerk