From:
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To:
Andrew Dunstan <andrew(at)dunslane(dot)net>
Cc:
ITAGAKI Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>,
"Patches (PostgreSQL)" <pgsql-patches(at)postgresql(dot)org>
Subject:
Re: [HACKERS] like/ilike improvements
Date:
2007-06-01 22:58:18
Message-ID:
25310.1180738698@sss.pgh.pa.us (view raw or flat )
Thread:
2007-05-22 15:58:33 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-22 16:12:51 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-22 16:30:37 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-22 16:51:51 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-22 17:01:14 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-22 17:40:36 from Andrew - Supernews <andrew+nonews(at)supernews(dot)com>
2007-05-22 19:04:32 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-22 22:37:24 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-23 14:34:06 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-23 14:41:09 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-23 14:52:44 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-23 16:00:54 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-23 16:07:10 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-24 00:36:17 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-24 00:36:17 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-24 17:17:47 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-24 18:02:35 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-24 23:32:19 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 01:26:19 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-25 01:56:58 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 02:03:42 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-25 03:20:51 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-25 03:34:13 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 05:20:16 from mark(at)mark(dot)mielke(dot)cc
2007-05-25 11:11:32 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 03:21:35 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 08:16:59 from "Zeugswetter Andreas ADI SD" <ZeugswetterA(at)spardat(dot)at>
2007-05-25 10:55:32 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-05-25 13:47:15 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-06-01 03:39:30 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-06-01 05:07:29 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>
2007-06-01 11:16:16 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-06-01 22:58:18 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-06-01 22:54:04 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-06-02 02:05:32 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-06-02 02:15:13 from Bruce Momjian <bruce(at)momjian(dot)us>
2007-05-25 13:42:18 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2007-05-23 05:55:04 from db(at)zigo(dot)dhs(dot)org
2007-05-22 18:44:25 from mark(at)mark(dot)mielke(dot)cc
2007-05-22 17:38:48 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-19 15:00:24 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-19 18:39:29 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-09-19 20:12:56 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-19 22:08:59 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-20 00:14:56 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-09-20 08:38:48 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-20 13:42:20 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-09-20 15:42:41 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-09-21 08:53:27 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-21 09:41:38 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>
2007-09-21 10:00:31 from Gregory Stark <stark(at)enterprisedb(dot)com>
2007-09-21 17:12:05 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-21 17:41:08 from Gregory Stark <stark(at)enterprisedb(dot)com>
2007-09-21 20:24:42 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2007-09-22 08:37:22 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
2007-09-22 11:20:24 from "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
Lists:
pgsql-hackers pgsql-patches
Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> ITAGAKI Takahiro wrote:
>> | SQL_ASCII | LATIN1 | UTF8 | EUC_JP
>> ---------+-----------+--------+-------+---------
>> HEAD | 8017 | 8029 | 16928 | 18213
>> Patched | 7899 | 7887 | 9985 | 10370 [ms]
>>
>> It improved the performance not only for UTF8, but also for other
>> multi-byte encodings and a bit for single-byte encodings.
> Interesting. I infer from these results that the biggest bang here comes
> from abandoning CHAREQ and doing all comparisons byte-wise.
It looks like CHAREQ and NextChar are both pretty expensive, no doubt
due to having to drill down through the MB encoding vectoring mechanism
to find out what to do.
A technique we might want to apply in future patches is to have an API
whereby we can get a direct function pointer to the appropriate mblen
or other encoding-dependent function, and then call directly to the
right place in the inner loops instead of having to go through the
intermediate vectoring function every time.
regards, tom lane
In response to
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