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* waiting for harddisk
@ 2008-03-24 13:05 petchimuthu lingam <spmlingam@gmail.com>
0 siblings, 2 replies; 3+ messages in thread
From: petchimuthu lingam @ 2008-03-24 13:05 UTC (permalink / raw)
To: pgsql-performance
i am using postgresql 8.1.8,
Following configurations:
shared_buffers = 5000
work_mem = 65536
maintenance_work_mem = 65536
effective_cache_size = 16000
random_page_cost = 0.1
The cpu is waiting percentage goes upto 50%, and query result comes later,
i am using normal select query ( select * from table_name ).
table has more then 6 million records.
--
With Best Regards,
Petchimuthulingam S
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: waiting for harddisk
@ 2008-03-24 13:20 PFC <lists@peufeu.com>
parent: petchimuthu lingam <spmlingam@gmail.com>
1 sibling, 0 replies; 3+ messages in thread
From: PFC @ 2008-03-24 13:20 UTC (permalink / raw)
To: petchimuthu lingam <spmlingam@gmail.com>; pgsql-performance
> i am using postgresql 8.1.8,
>
> Following configurations:
> shared_buffers = 5000
> work_mem = 65536
> maintenance_work_mem = 65536
> effective_cache_size = 16000
> random_page_cost = 0.1
>
> The cpu is waiting percentage goes upto 50%, and query result comes
> later,
>
> i am using normal select query ( select * from table_name ).
>
> table has more then 6 million records.
When you mean SELECT *, are you selecting the WHOLE 6 million records ?
Without WHERE ? Or just a few rows ?
Please post EXPLAIN ANALYZE of your query.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: waiting for harddisk
@ 2008-03-25 01:13 Scott Marlowe <scott.marlowe@gmail.com>
parent: petchimuthu lingam <spmlingam@gmail.com>
1 sibling, 0 replies; 3+ messages in thread
From: Scott Marlowe @ 2008-03-25 01:13 UTC (permalink / raw)
To: petchimuthu lingam <spmlingam@gmail.com>; +Cc: pgsql-performance
On Mon, Mar 24, 2008 at 7:05 AM, petchimuthu lingam <spmlingam@gmail.com> wrote:
> i am using postgresql 8.1.8,
>
> Following configurations:
> shared_buffers = 5000
> work_mem = 65536
> maintenance_work_mem = 65536
> effective_cache_size = 16000
> random_page_cost = 0.1
That number, 0.1 is not logical. anything below 1.0 is generally a
bad idea, and means that you've got some other setting wrong.
> The cpu is waiting percentage goes upto 50%, and query result comes later,
>
> i am using normal select query ( select * from table_name ).
>
> table has more then 6 million records.
You need faster disks if you want sequential scans to go faster. Look
into a decent RAID controller (Areca, Escalade (forgot what they're
called now) or LSI) with battery backed cache. Run RAID-10 on it with
as many drives as you can afford to throw at the problem.
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2008-03-25 01:13 UTC | newest]
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2008-03-24 13:05 waiting for harddisk petchimuthu lingam <spmlingam@gmail.com>
2008-03-24 13:20 ` PFC <lists@peufeu.com>
2008-03-25 01:13 ` Scott Marlowe <scott.marlowe@gmail.com>
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