Re: simple update queries take a long time - postgres 8.3.1 - Mailing list pgsql-general

From mark
Subject Re: simple update queries take a long time - postgres 8.3.1
Date
Msg-id 82fa9e310803311303t1af4091anc87aabad2cc1d6a5@mail.gmail.com
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In response to Re: simple update queries take a long time - postgres 8.3.1  (Raymond O'Donnell <rod@iol.ie>)
List pgsql-general
On Mon, Mar 31, 2008 at 12:59 PM, Raymond O'Donnell <rod@iol.ie> wrote:
On 31/03/2008 20:51, mark wrote:

> can you explain what the numbers mean in the EXPLAIN ANALYZE?
> (cost=0.00..8.46 rows=1 width=1073)  (actual time=0.094..0.161 rows=1
> loops=1)

It's worth reading through the docs at that reference in my previous
email - it's well explained there.

As I understand it, "cost" signifies the planner's estimate of how long
the query will take, in terms of disk page fetches. The "actual time" is
in milliseconds.
 
this is my RAID and HD configuration.. is this a good enough configuration? is this slowing down my queries?
 
Raid Controller: 3Ware 9650SE-4LPML, 4x CHs Multi-Lane, LP PCI-e(4x) SATA2 Raid Controller, 256MB
HDD: 4x 500GB/7200 RPM, U300, SATA2 Drive, 16M (RAID 10)

the IO wait is most of the times 10-30%

top - 13:02:35 up 33 days,  4:05,  3 users,  load average: 2.65, 2.82, 2.61
Tasks: 1040 total,   1 running, 1039 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.7%us,  0.6%sy,  0.0%ni, 85.3%id, 13.2%wa,  0.0%hi,  0.0%si,  0.0%st

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