On 2013-09-11 11:35:45 -0700, Josh Berkus wrote: > All, > > We've confirmed that this issue is caused by having long-running idle > transactions on the server. When we disabled their queueing system > (which prodiced hour-long idle txns), the progressive slowness went away. > > Why that should affect 9.X far more strongly than 8.4, I'm not sure > about. Does that mean that 8.4 was unsafe, or that this is something > which *could* be fixed in later versions? The explanation is in http://archives.postgresql.org/message-id/20130910132133.GJ1024477%40alap2.anarazel.de The referenced commit introduced a planner feature. Funnily you seem to have been the trigger for it's introduction ;) > I'm also confused as to why this would affect BIND time rather than > EXECUTE time. Because we're doing the histogram checks during planning and not during execution. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance