On 05.11.2012 16:32, Claudio Freire wrote:
On Sun, Nov 4, 2012 at 7:23 PM, Dong Ye<yed@xxxxxxxxxx> wrote:
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).
You know... it does look as if 9.2.1 is generating a lot more pressure
into the memory allocator (AllocSetAlloc notably higher).
Did you check the access plans of the queries? 9.2 planner might choose
a slightly worse plan. Or perhaps index-only scans are hurting
performance with the DBT-2 queries.
- Heikki
--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
