From: Gábriel Ákos <akos.gabriel@i-logic.hu>
To: pgsql-performance@postgresql.org
Subject: Re: count(*) performance
Date: Mon, 27 Mar 2006 20:04:46 +0200
Message-ID: <4428293E.9080300@i-logic.hu> (raw)
In-Reply-To: <C04D537E.2025E%llonergan@greenplum.com>
References: <C04D537E.2025E%llonergan@greenplum.com>
Luke Lonergan wrote:
> To test your disk speed, use the following commands and report the times
> here:
>
> time bash -c "dd if=/dev/zero of=bigfile bs=8k count=500000 && sync"
root@panther:/fast # time bash -c "dd if=/dev/zero of=bigfile bs=8k
count=500000 && sync"
500000+0 records in
500000+0 records out
4096000000 bytes transferred in 45.469404 seconds (90082553 bytes/sec)
real 0m56.880s
user 0m0.112s
sys 0m18.937s
> time dd if=bigfile of=/dev/null bs=8k
root@panther:/fast # time dd if=bigfile of=/dev/null bs=8k
500000+0 records in
500000+0 records out
4096000000 bytes transferred in 53.542147 seconds (76500481 bytes/sec)
real 0m53.544s
user 0m0.048s
sys 0m10.637s
I guess these values aren't that bad :)
--
Üdvözlettel,
Gábriel Ákos
-=E-Mail :akos.gabriel@i-logic.hu|Web: http://www.i-logic.hu=-
-=Tel/fax:+3612367353 |Mobil:+36209278894 =-
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To: pgsql-performance@postgresql.org
Cc: akos.gabriel@i-logic.hu
Subject: Re: count(*) performance
In-Reply-To: <4428293E.9080300@i-logic.hu>
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