On Sun, Aug 28, 2011 at 5:54 AM, Greg Smith <greg@2ndquadrant.com> wrote:
> Updated patch cleans up two diff mistakes made when backing out the progress
> report feature. The tip-off I screwed up should have been the absurdly high
> write rate shown. The usleep was accidentally deleted, so it was running
> without cost limits even applying. Here's a good one instead:
>
> LOG: automatic vacuum of table "pgbench.public.pgbench_accounts": index
> scans: 1
> pages: 0 removed, 163935 remain
> tuples: 2000000 removed, 2928356 remain
> buffer usage: 117393 hits, 123351 misses, 102684 dirtied, 2.168 MiB/s
> write rate
> system usage: CPU 2.54s/6.27u sec elapsed 369.99 sec
I postulate that this change isn't needed until you get to the part
where we do some kind of intermediate progress reporting:
! if (Log_autovacuum_min_duration > 0 || VacuumCostActive)
Instead of doing this only when vacuum costing is active, could we
drive it off of the pgBufferUsage stuff (maybe with a few tweaks...)
and do it unconditionally?
To me it seems like it would better to say "write rate xyz MB/s"
rather than "xyz MB/s write rate", but maybe I'm in the minority on
that one.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company