Re: Non-C locale and LIKE

From: Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp>
To: pgman(at)candle(dot)pha(dot)pa(dot)us
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Non-C locale and LIKE
Date: 2004-11-28 08:25:24
Message-ID: 20041128.172524.74751187.t-ishii@sra.co.jp
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

> I know we can't currently use an index with non-C locales and LIKE
> except when we create a sepcial type of index for LIKE indexing
> (text_pattern_ops).
>
> However, I am wondering if we should create a character lookup during
> initdb that has the characters ordered so we can do:
>
> col LIKE 'ha%' AND col >= "ha" and col <= "hb"
>
> Could we do this easily for single-character encodings? We could have:
>
> A 1
> B 2
> C 3
>
> and a non-C locale could be:
>
> A 1
> A` 2
> B 3
>
> We can't handle multi-byte encodings because the number of combinations
> is too large or not known.
>
> Also, we mention you should use the "C" locale to use normal indexes for
> LIKE but isn't it more correct to say the encoding has to be SQL_ASCII?

Why? "C" locale works well for multibyte encodings such as EUC-JP too.
--
Tatsuo Ishii

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Peter Eisentraut 2004-11-28 08:26:32 Re: Fix for NLS in pgport
Previous Message John Hansen 2004-11-28 06:34:02 Re: Non-C locale and LIKE