Re: qsort again (was Re: [PERFORM] Strange Create Index

From: Martijn van Oosterhout <kleptog(at)svana(dot)org>
To: Jens-Wolfhard Schicke <j(dot)schicke(at)asco(dot)de>
Cc: Dann Corbit <DCorbit(at)connx(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: qsort again (was Re: [PERFORM] Strange Create Index
Date: 2006-02-17 09:17:49
Message-ID: 20060217091749.GA9254@svana.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-performance

On Fri, Feb 17, 2006 at 09:18:39AM +0100, Jens-Wolfhard Schicke wrote:
> What I think as the biggest problem is the digit representation necessary
> for Radix-Sort in cases of locales which sort without looking at spaces. I
> assume that would be hard to implement. The same goes for the proposed
> mapping of string values onto 4/8-byte values.

Actually, this is easy. The standard C library provides strxfrm() and
other locale toolkits like ICU provide ucol_getSortKey(). Windows
provides LCMapString(). Just pass each string through this and take the
first four bytes of the result to form your integer key.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Ragnar 2006-02-17 09:24:21 Re: [HACKERS] qsort again (was Re: Strange Create
Previous Message Christian Bird 2006-02-17 08:26:03 who is pgsql in cvs

Browse pgsql-performance by date

  From Date Subject
Next Message Ragnar 2006-02-17 09:24:21 Re: [HACKERS] qsort again (was Re: Strange Create
Previous Message Jens-Wolfhard Schicke 2006-02-17 08:18:39 Re: qsort again (was Re: [PERFORM] Strange Create Index