Skip site navigation (1) Skip section navigation (2)

Re: [PATCHES] COPY FROM performance improvements

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: Mark Wong <markw(at)osdl(dot)org>
Cc: Luke Lonergan <llonergan(at)greenplum(dot)com>,Patrick Welche <prlw1(at)newn(dot)cam(dot)ac(dot)uk>,pgsql-performance(at)postgresql(dot)org, maryedie(at)osdl(dot)org
Subject: Re: [PATCHES] COPY FROM performance improvements
Date: 2005-07-28 23:57:24
Message-ID: 42E970E4.4010902@commandprompt.com (view raw or flat)
Thread:
Lists: pgsql-patchespgsql-performance
>>
>>>[root(at)pq-slave root]# /sbin/hdparm -tT /dev/sda
>>>
>>>/dev/sda:
>>>  Timing buffer-cache reads:   1816 MB in  2.00 seconds = 908.00 MB/sec
>>>  Timing buffered disk reads:   26 MB in  3.11 seconds =   8.36 MB/sec
>>>[root(at)pq-slave root]#
>>
>>Can you post the "time dd if=/dev/zero of=bigfile bs=8k count=500000"
>>results?  Also do the reverse (read the file) with "time dd if=bigfile
>>of=/dev/null bs=8k".

I didn't see this come across before... here ya go:

time dd if=/dev/zero of=bigfile bs=8k count=500000

500000+0 records in
500000+0 records out

real    1m52.738s
user    0m0.310s
sys     0m36.590s

time dd if=bigfile of=/dev/null bs=8k

time dd if=bigfile of=/dev/null bs=8k
500000+0 records in
500000+0 records out

real    4m38.742s
user    0m0.320s
sys     0m27.870s


FYI on your hardware raid comment... I easily get 50 megs a second on my 
3ware controllers and faster on my LSI SATA controllers.

Sincerely,

Joshua D. Drake




>
-- 
Your PostgreSQL solutions provider, Command Prompt, Inc.
24x7 support - 1.800.492.2240, programming, and consulting
Home of PostgreSQL Replicator, plPHP, plPerlNG and pgPHPToolkit
http://www.commandprompt.com / http://www.postgresql.org

In response to

Responses

pgsql-performance by date

Next:From: Matthew SchumacherDate: 2005-07-29 00:13:19
Subject: Re: Performance problems testing with Spamassassin 3.1.0
Previous:From: Mark WongDate: 2005-07-28 23:43:52
Subject: Re: [PATCHES] COPY FROM performance improvements

pgsql-patches by date

Next:From: Bruce MomjianDate: 2005-07-29 03:12:37
Subject: Re: ALTER OBJECT SET SCHEMA
Previous:From: Mark WongDate: 2005-07-28 23:43:52
Subject: Re: [PATCHES] COPY FROM performance improvements

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group