> You are using prepared statements, this makes me think that this > regression might be due to support for parameter specific plans for > prepared statements. [1] Can you run the test on both versions without > prepared statements and see if the regressions remains. Without prepare statement, we got 48837.33 avg notpm with 9.1.6 and 43264.54 avg notpm with 9.2.1. notps over time shows the slowdown of 9.2.1 is evident during the entire course of the run. Their profiles are posted on http://pgsql.privatepaste.com/b770f72967 (9.1.6) and http://pgsql.privatepaste.com/6fa8b7f174 (9.2.1). Thanks, Dong -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance