Re: slow query performance - Mailing list pgsql-performance

From Anj Adu
Subject Re: slow query performance
Date
Msg-id AANLkTikuvlQCq2FUyOPYfmh_A2by39rMsIB3vDRCbaUk@mail.gmail.com
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In response to Re: slow query performance  (Anj Adu <fotographs@gmail.com>)
Responses Re: slow query performance
List pgsql-performance
I changed random_page_cost=4 (earlier 2) and the performance issue is gone

I am not clear why a page_cost of 2 on really fast disks would perform badly.

Thank you for all your help and time.

On Thu, Jun 10, 2010 at 8:32 AM, Anj Adu <fotographs@gmail.com> wrote:
> Attached
>
> Thank you
>
>
> On Thu, Jun 10, 2010 at 6:28 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Wed, Jun 9, 2010 at 11:17 PM, Anj Adu <fotographs@gmail.com> wrote:
>>> The plan is unaltered . There is a separate index on theDate as well
>>> as one on node_id
>>>
>>> I have not specifically disabled sequential scans.
>>
>> Please do "SHOW ALL" and attach the results as a text file.
>>
>>> This query performs much better on 8.1.9 on a similar sized
>>> table.(althought the random_page_cost=4 on 8.1.9 and 2 on 8.4.0 )
>>
>> Well that could certainly matter...
>>
>> --
>> Robert Haas
>> EnterpriseDB: http://www.enterprisedb.com
>> The Enterprise Postgres Company
>>
>

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