Re: plan time of MASSIVE partitioning ...
Leonardo Francalanci <m_lists@yahoo.it>
From: Leonardo Francalanci <m_lists@yahoo.it>
To: Boszormenyi Zoltan <zb@cybertec.at>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers Hackers <pgsql-hackers@postgresql.org>
Date: 2010-10-29T08:48:59Z
Lists: pgsql-hackers
> On the other hand, if I use a similar test case to my original one
> (i.e. the tables are much wider) then the query planning takes
> 1.42 seconds in 9.1 with this patch instead of about 4.7 seconds
> as we observed it using PostgreSQL 9.0.0. The beginning of the gprof
> output now looks like this:
Hi,
I'm really interested in this patch.
I tried a simple test case:
create table t (a integer, b text);
DO $$DECLARE i int;
BEGIN
FOR i IN 0..9000 LOOP
EXECUTE 'create table t' || i || ' ( CHECK (a >' || i*10 || '
and a <= ' || (i+1)*10 || ' ) ) INHERITS (t)';
EXECUTE 'create index tidx' || i || ' ON t' || i || ' (a)';
END LOOP;
END$$;
explain select * from t where a > 1060 and a < 1090;
but I don't get any gain from the patch... explain time is still around 250 ms.
Tried with 9000 partitions, time is still 2 secs.
Maybe I've missed completely the patch purpose?
(I tried the test case at
http://archives.postgresql.org/message-id/4CBD9DDC.4040304@cybertec.at
and that, in fact, gets a boost with this patch).
Leonardo