Joe Tomcat <tomcat@mobile.mp> writes:
> I want postmaster to consume
> basically all available RAM,
This is generally considered a bad idea.
> so any query which is a read (not an
> updating query) shouldn't have to touch disk at all.
You do not need to mess with Postgres' settings to make that happen.
The kernel should buffer recently-accessed disk blocks in free RAM,
without you having to do anything special.
See the list archives for much more on the theory and practice of
buffer tuning.
regards, tom lane