On Tue, Dec 11, 2012 at 2:50 AM, Patryk Sidzina <patryk.sidz...@gmail.com> wrote:
> The differences come up when you change the "INSERT" to "EXECUTE 'INSERT'" ( > and i checked this time on 3 machines, one of which was Windows): > > CREATE TEMP TABLE test_table_md_speed(id serial primary key, n integer); > > CREATE OR REPLACE FUNCTION test_db_speed(cnt integer) > RETURNS text > LANGUAGE plpgsql > AS $function$ > DECLARE > time_start timestamp; > time_stop timestamp; > time_total interval; > BEGIN > time_start := cast(timeofday() AS TIMESTAMP); > FOR i IN 1..cnt LOOP > EXECUTE 'INSERT INTO test_table_md_speed(n) VALUES (' || i > || ')'; > END LOOP; > > time_stop := cast(timeofday() AS TIMESTAMP); > time_total := time_stop-time_start; > > RETURN extract (milliseconds from time_total); > END; > $function$; > > SELECT test_db_speed(100000); The culprit is the commit below. I don't know exactly why this slows down your case. A preliminary oprofile analysis suggests that it most of the slowdown is that it calls AllocSetAlloc more often. I suspect that this slow-down will be considered acceptable trade-off for getting good parameterized plans. commit e6faf910d75027bdce7cd0f2033db4e912592bcc Author: Tom Lane <t...@sss.pgh.pa.us> Date: Fri Sep 16 00:42:53 2011 -0400 Redesign the plancache mechanism for more flexibility and efficiency. Cheers, Jeff -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance