Обсуждение: How to increase postgresql performance

Hi

I have an sql query which takes 20 seconds to be executed.

this sql query contain more than 870 id under the select where in () condition.

So , it is not a large row result but a big list of conditions to be crossed.

I'm using postgresql 8.4.

Thanks for help

On Tue, Feb 02, 2010 at 11:51:57AM +0100, fida aljounaidi wrote:
> Hi
>
> I have an sql query which takes 20 seconds to be executed.
>
> this sql query contain more than 870 id under the select where in ()
> condition.

Add a column to the table which denotes the characteristic that those
870 ids share, and select based on that?

>
> So , it is not a large row result but a big list of conditions to be
> crossed.
>
> I'm using postgresql 8.4.
>
> Thanks for help

And maybe make sure that the id column is indexed, and see what
EXPLAIN says. http://wiki.postgresql.org/wiki/Using_EXPLAIN

--
Ian.


On Tue, Feb 2, 2010 at 10:56 AM, Bret S. Lambert <bret.lambert@gmail.com> wrote:
> On Tue, Feb 02, 2010 at 11:51:57AM +0100, fida aljounaidi wrote:
>> Hi
>>
>> I have an sql query which takes 20 seconds to be executed.
>>
>> this sql query contain more than 870 id under the select where in ()
>> condition.
>
> Add a column to the table which denotes the characteristic that those
> 870 ids share, and select based on that?
>
>>
>> So , it is not a large row result but a big list of conditions to be
>> crossed.
>>
>> I'm using postgresql 8.4.
>>
>> Thanks for help
>
> --
> Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-admin
>

USE LEFT/JOIN instead of WHERE IN possibly would improve the performance..


On Tue, Feb 2, 2010 at 5:51 PM, fida aljounaidi
<fida.aljounaidi@gmail.com> wrote:
> Hi
>
> I have an sql query which takes 20 seconds to be executed.
>
> this sql query contain more than 870 id under the select where in ()
> condition.
>
> So , it is not a large row result but a big list of conditions to be
> crossed.
>
> I'm using postgresql 8.4.
>
> Thanks for help
>
>
>



--
Regards,
Kiswono P
GB

On Tue, Feb 2, 2010 at 3:51 AM, fida aljounaidi
<fida.aljounaidi@gmail.com> wrote:
> Hi
>
> I have an sql query which takes 20 seconds to be executed.
>
> this sql query contain more than 870 id under the select where in ()
> condition.
>
> So , it is not a large row result but a big list of conditions to be
> crossed.
>
> I'm using postgresql 8.4.

In addition to the things already posted, post your query and the
output of explain analyze yourquery to the list and let us have a
look.