Re: [HACKERS] Postgres 6.5 beta2 and beta3 problem

On Wed, 9 Jun 1999, Bruce Momjian wrote:

> Date: Wed, 9 Jun 1999 08:43:50 -0400 (EDT)
> From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
> To: Daniel Kalchev <daniel(at)digsys(dot)bg>
> Cc: Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp>, pgsql-hackers(at)postgreSQL(dot)org
> Subject: Re: [HACKERS] Postgres 6.5 beta2 and beta3 problem
>
> > Yes,
> >
> > I do build with --enable-locale, but I do not build with --enable-mb and do
> > not use client_encoding or server_encoding.
> >
> > The content of the keys is in cyrillic. I have LC_CTYPE=CP1251 in the
> > environment in both server and client, and this has worked for me in 6.4.2.
>
>
> This certainly explains it. With locale enabled, LIKE does not use
> indexes because we can't figure out how to do the indexing trick with
> non-ASCII character sets because we can't figure out the maximum
> character value for a particular encoding.

If so, why explain reports 'Index Scan ....' ?
apod=> \d
Database = apod
+------------------+----------------------------------+----------+
| Owner | Relation | Type |
+------------------+----------------------------------+----------+
| megera | idx_adate | index |
| megera | idx_atitle | index |
| megera | idx_url | index |
| megera | titles | table |
+------------------+----------------------------------+----------+

apod=> explain select atitle from titles where atitle like 'Sun%';
NOTICE: QUERY PLAN:

Index Scan using idx_atitle on titles (cost=33.28 rows=1 width=12)

Current cvs, --enable-locale --with-mb=KOI8

Regards,

Oleg
>
> We didn't do the check in 6.4.*, and LIKE was not returning the proper
> results for queries at those sites that used locale.
>
> --
> Bruce Momjian | http://www.op.net/~candle
> maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
> + If your life is a hard drive, | 830 Blythe Avenue
> + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
>

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83