Re: like/ilike improvements

From: Andrew Dunstan <andrew(at)dunslane(dot)net>
To: Guillaume Smet <guillaume(dot)smet(at)gmail(dot)com>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: like/ilike improvements
Date: 2007-09-20 13:42:20
Message-ID: 46F278BC.1080508@dunslane.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-patches

Guillaume Smet wrote:

app_hls

> On 9/20/07, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
>
>> Can you retry both sets of tests but this time in C locale? The lower()
>> code works differently in C locale, and it might be that we need to look
>> at tweaking just one case.
>>
>
>

Please try the attached patch, which goes back to using a special case
for single-byte ILIKE. I want to make sure that at the very least we
don't cause a performance regression with the code done this release. I
can't see an obvious way around the problem for multi-byte case -
lower() then requires converting to and from wchar, and I don't see a
way of avoiding calling lower(). If this is a major blocker I would
suggest you look at an alternative to using ILIKE for your UTF8 data.

cheers

andrew

Attachment Content-Type Size
ilikefix.patch text/x-patch 4.7 KB

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2007-09-20 14:35:25 Re: Improving the Performance of Full Table Updates
Previous Message Martin Pihlak 2007-09-20 13:08:58 Re: stored procedure stats in collector

Browse pgsql-patches by date

  From Date Subject
Next Message Euler Taveira de Oliveira 2007-09-20 15:19:39 Re: Implementation of aggregate functions
Previous Message Hannes Eder 2007-09-20 12:06:08 minor compiler warning in backend/utils/adt/tsrank.c