(re-adding hackers) On Fri, Feb 1, 2013 at 2:46 PM, Vlad Bailescu <v...@mojitosoftware.com> wrote: > > I'm pretty sure the io is from the autovacuum on master table because it's > last_autovacuum stats update almost every minute
That only proves that the master table is being vacuumed, but does not necessarily say that others are not. I would suggest turning auto vacuum logging on. > and iotop shows something > like: > > Total DISK READ: 5.80 M/s | Total DISK WRITE: 115.85 K/s > TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND > 7681 be/4 postgres 5.93 M/s 0.00 B/s 0.00 % 63.62 % postgres: > autovacuum worker process fleet Whats interesting is that there is a lot of reads happening, but very little writes. I can see a scenario when this can happen even with visibility maps because vacuum honors visibility map only if it can skip 32 blocks at stretch, but your other claim that this goes on for 90 seconds even though the table is just couple of MBs is hard to justify. How does the auto vacuum settings look like ? I wonder if you have scaled down naptime and threshold just too low. Thanks, Pavan -- Pavan Deolasee http://www.linkedin.com/in/pavandeolasee -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
