On Tue, Mar 27, 2012 at 3:22 PM, Ants Aasma <a...@cybertec.at> wrote: > On Tue, Mar 27, 2012 at 9:58 PM, Robert Haas <robertmh...@gmail.com> wrote: >> I've committed the core of this. I left out the stats collector >> stuff, because it's still per-table and I think perhaps we should back >> off to just per-database. I changed it so that it does not conflate >> wait time with I/O time. Maybe there should be a separate method of >> measuring wait time, but I don't think it's a good idea for the >> per-backend stats to measure a different thing than what gets reported >> up to the stats collector - we should have ONE definition of each >> counter. I also tweaked the EXPLAIN output format a bit, and the >> docs. > > Thank you for working on this. > > Taking a fresh look at it, I agree with you that conflating waiting > for backend local IO, and IO performed by some other backend might > paint us into a corner. For most workloads the wait for IO performed > by others should be the minority anyway. > > I won't really miss the per table stats. But if the pg_stat_statements > normalisation patch gets commited, it would be really neat to also > have IO waits there. It would be much easier to quickly diagnose "what > is causing all this IO" issues.
So, the pg_stat_statements part of this is committed now. Do you want to prepare a revised patch to add per-database counters to the statistics collector? I think that might be a good idea... -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers