On Wed, Oct 23, 2013 at 8:52 PM, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > Hmm, now if we had portable atomic addition, so that we could spare the > spinlock ...
That certainly seems like an interesting possibility. I think that pg_stat_statements should be made to do this kind of thing by a third party tool that aggregates snapshots of deltas. Time-series data, including (approximate) *local* minima and maxima should be built from that. I think tools like KONDO-san's pg_statsinfo tool have an important role to play here. I would like to see it or a similar tool become a kind of defacto standard for consuming pg_stat_statements' output. At this point we are in general very much chasing diminishing returns by adding new things to the counters struct, particularly given that it's currently protected by a spinlock. And adding a histogram or min/max for something like execution time isn't an approach that can be made to work for every existing cost tracked by pg_stat_statements. So, taking all that into consideration, I'm afraid this patch gets a -1 from me. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
