Re: cache estimates, cache access cost

On Tue, May 17, 2011 at 6:11 PM, Cédric Villemain
<cedric.villemain.debian@gmail.com> wrote:
> The point is to get ratio in cache, not the distribution of the data
> in cache (pgfincore also allows you to see this information).
> I don't see how a stable (a server in production) system can have its
> ratio moving up and down so fast without known pattern.

Really?  It doesn't seem that hard to me.  For example, your nightly
reports might use a different set of tables than are active during the
day....

> PS: there is very good blocker for the pg_class changes : what happens
> in a standby ? Maybe it just opens the door on how to unlock that or
> find another option to get the information per table but distinct per
> server. (or we don't care, at least for a first implementation, like
> for other parameters)

That's a good point, too.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company