X-Original-To: pgsql-benchmarks-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 6CF7A329E47; Fri, 8 Oct 2004 09:47:51 +0100 (BST) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 32175-09; Fri, 8 Oct 2004 08:47:44 +0000 (GMT) Received: from mailer.unicite.fr.netcentrex.net (unknown [62.161.167.249]) by svr1.postgresql.org (Postfix) with ESMTP id 777A7329E51; Fri, 8 Oct 2004 09:47:43 +0100 (BST) Received: from [192.168.101.228] ([192.168.101.228]) by mailer.unicite.fr.netcentrex.net with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2657.72) id 42CX03QZ; Fri, 8 Oct 2004 10:47:42 +0200 Message-ID: <4166542E.2020809@fr.netcentrex.net> Date: Fri, 08 Oct 2004 10:47:42 +0200 From: =?ISO-8859-1?Q?=22Alban_M=E9dici_=28NetCentrex=29=22?= User-Agent: Mozilla Thunderbird 0.8 (Windows/20040913) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Tom Lane Cc: pgsql-benchmarks@postgresql.org, pgsql-performance@postgresql.org Subject: Re: [PERFORM] stats on cursor and query execution troubleshooting References: <4163C5C3.3030304@fr.netcentrex.net> <25576.1097072199@sss.pgh.pa.us> In-Reply-To: <25576.1097072199@sss.pgh.pa.us> Content-Type: multipart/alternative; boundary="------------030409030803050401070308" X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.5 tagged_above=0.0 required=5.0 tests=HTML_20_30, HTML_MESSAGE X-Spam-Level: X-Archive-Number: 200410/3 X-Sequence-Number: 20 This is a multi-part message in MIME format. --------------030409030803050401070308 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Thanks for your repply, but I still don"t understand why the statistic=20 logs : ! 0/0 [0/0] filesystem blocks in/out it told me there is no hard disk access, I'm sure there is, I heard my=20 HDD, and see activity using gkrellm (even using my first query ; big=20 select *) ? 2004-10-08 10:40:05 DEBUG: query: select * from "LINE_Line"; 2004-10-08 10:40:53 DEBUG: QUERY STATISTICS ! system usage stats: ! 48.480196 elapsed 42.010000 user 0.700000 system sec ! [42.030000 user 0.720000 sys total] ! 0/0 [0/0] filesystem blocks in/out ! 6/23 [294/145] page faults/reclaims, 0 [0] swaps ! 0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent ! 0/0 [0/0] voluntary/involuntary context switches ! postgres usage stats: ! Shared blocks: 3902 read, 0 written, buffer hit=20 rate =3D 11.78% ! Local blocks: 0 read, 0 written, buffer hit=20 rate =3D 0.00% ! Direct blocks: 0 read, 0 written looking at the web some logs, I saw those fields filled (i/o filesystem) Does my postgresql.conf missing an option or is therer a known bug of my=20 postgresql server 7.2.4 ? thx regards Alban M=E9dici on 06/10/2004 16:16 Tom Lane said the following: >=3D?ISO-8859-1?Q?=3D22Alban_M=3DE9dici_=3D28NetCentrex=3D29=3D22?=3D writes: >=20=20 > >>I'm looking for the statistic of memory, CPU, filesystem access while= =3D20 >>executing some regular SQL query, and I want to compare them to >>same kind of results while executing a cursor function. >>=20=20=20=20 >> > >I think your second query is finding all the disk pages it needs in >kernel disk cache, because they were all read in by the first query. >This has little to do with cursor versus non cursor, and everything >to do with hitting recently-read data again. > > regards, tom lane > >=20=20 > --=20 Alban M=E9dici R&D software engineer ------------------------------ you can contact me @ : http://www.netcentrex.net ------------------------------ --------------030409030803050401070308 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Thanks for your repply, but I still don"t understand why the statistic logs :

!       0/0 [0/0] filesystem blocks in/out

it told me there is no hard disk access, I'm sure there is, I heard my HDD, and see activity using gkrellm (even using my first query ; big select *) ? 2004-10-08 10:40:05 DEBUG: query: select * from "LINE_Line"; 2004-10-08 10:40:53 DEBUG: QUERY STATISTICS ! system usage stats: ! 48.480196 elapsed 42.010000 user 0.700000 system sec ! [42.030000 user 0.720000 sys total] ! 0/0 [0/0] filesystem blocks in/out ! 6/23 [294/145] page faults/reclaims, 0 [0] swaps ! 0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent ! 0/0 [0/0] voluntary/involuntary context switches ! postgres usage stats: ! Shared blocks: 3902 read, 0 written, buffer hit rate = 11.78% ! Local blocks: 0 read, 0 written, buffer hit rate = 0.00% ! Direct blocks: 0 read, 0 written looking at the web some logs, I saw those fields filled (i/o filesystem) Does my postgresql.conf missing an option or is therer a known bug of my postgresql server 7.2.4 ? thx regards Alban Médicion 06/10/2004 16:16 Tom Lane said the following:

=?ISO-8859-1?Q?=22Alban_M=E9dici_=28NetCentrex=29=22?= <amedici@fr.netcentrex.net> writes:

I'm looking for the statistic of memory,  CPU,  filesystem access while=20
executing some regular SQL query,  and I want to compare them to
same kind of results while executing a cursor function.


I think your second query is finding all the disk pages it needs in
kernel disk cache, because they were all read in by the first query.
This has little to do with cursor versus non cursor, and everything
to do with hitting recently-read data again.

			regards, tom lane

-- 
Alban Médici
R&D software engineer
------------------------------
you can contact me @ :
http://www.netcentrex.net
------------------------------

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