Re: [HACKERS] Postgres 6.5 beta2 and beta3 problem

On Wed, 9 Jun 1999, Daniel Kalchev wrote:

> Date: Wed, 09 Jun 1999 16:15:58 +0300
> From: Daniel Kalchev <daniel(at)digsys(dot)bg>
> To: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
> Cc: pgsql-hackers(at)postgreSQL(dot)org
> Subject: Re: [HACKERS] Postgres 6.5 beta2 and beta3 problem
>
> Bruce,
>
> This is extremely bad news, because if will make PostgreSQL 6.5 unusable for
> most of my applications. Perhaps something can be done to resolve this
> situation?
>
> I understand the problem for 16-bit characters support, but for most of the
> encodings that support only 8 bit characters it should be safe to assume the
> maximum character value is 255.
>
> Anyway, making this check compile-time defined would certainly fix things
> here, because in my case the cyrillic letters order match that of the binary
> encoding (that is, the first alphabet letter is before the second etc).
>
> Perhaps the locale data can be used to gather this information?

It's certainly there ! locale data contains all information about
specific character set and encoding. Is it possible to use it to create
indices ? It should be slower but benefits of using indices will cover
expenses for non-US people. I didn't notice such behaivour in Informix
and Oracle. Fixing this would be a good point in respect of popularity
of Postgres. Are there any chance to place it in TODO for 6.6 ?
At least explain should reflect such fact !

Regards,

Oleg

>
> I will do some testing without using locale to see what happens.
>
> Regards,
> Daniel
>
> >>>Bruce Momjian said:
> > > Yes,
> > >
> > > I do build with --enable-locale, but I do not build with --enable-mb and d
> o
> > > 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.
> >
> > 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