Re: Server instrumentation for 8.1

Andrew - Supernews wrote:
> On 2005-05-12, Andreas Pflug <pgadmin@pse-consulting.de> wrote:

> 
> relpages is updated from the value of RelationGetNumberOfBlocks(rel) which
> is definitive (it gets the value from smgr which gets it from the physical
> file sizes); the only inaccuracy is that it is correct only as of the time
> that the pg_class row was last updated (as done by any VACUUM, any ANALYZE,
> any CLUSTER or any CREATE INDEX on the table, at minimum).

"accurate unless vacuum not running".
... which renders it quite useless to find out about *real* disk usage. 
Interesting for the query planner, not for the admin to know when a 
vacuum full might be necessary.

Regards,
Andreas