[HELP] buffers and query's

Hi
I want do something that can seem a little bit strange: I'm doing a project
and I don't want that the executing plan was known by the system.
I've got many different query's and some of them are nearly similar. I have
to know how many time it takes to postgresql to do my project.

I've been looking for something similar to: alter system flush shared_pool,
used in Oracle system, but i haven't found nothing.

Does anybody have any idea to do this?

I  think the thing could be reset shared buffers, but I don't know how to do
it


yours

Cris..