Erik Jones <erik@myemma.com> writes:
> Well, disk reads, cache hits, transactions commited, transactions
> rolled back, index size and usage, etc. are all able to be tracked vi
> the pg catalogue tables and views. But, I haven't seen anything that
> will give me numbers on actual disk writes done by the database.
One of the reasons you don't see that is that a large fraction of the
writes are triggered in background by the "bgwriter" process, which
operates at too low a level to participate in the stats collection
mechanism. I'm not sure what would be involved in refactoring things
sufficiently to make that workable, but it'd be nontrivial.
regards, tom lane