Re: Enough RAM for entire Database.. cost aside, is this

Greetings!

On Fri, 2 Jul 2004, Mike Rylander wrote:

> I find that experience does not bear this out. There is a saying a coworker
> of mine has about apps that try to solve problems, in this case caching,
> that are well understood and generally handled well at other levels of the
> "software stack"... he calls them "too smart by half" :)

But on the other hand, general algorithms which are designed to work under
a wide variety of circumstances may fail in specific cases. I am thinking
of VACUUM which would kill most caching algorithms simply because we
cannot tell the O/S "by the by, this set of pages will not be used again,
and therefore it would be fine to use almost none of the general cache to
store this". All algorithms have assumptions of value distribution and
usages. Caches depend on locality of reference, and we do not have an easy
way to say when this is broken.

Regards!
Ed