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@candle.pha.pa.us>
> To: Daniel Kalchev <daniel@digsys.bg>
> Cc: Hiroshi Inoue <Inoue@tpf.co.jp>, pgsql-hackers@postgreSQL.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@candle.pha.pa.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@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83