How to increase postgresql performance

[fida aljounaidi <fida.aljounaidi@xxxxxxxxx>]

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