pgsql-general-owner@xxxxxxxxxxxxxx wrote: > Did you analyse the table? Hi, Yes, I did. > Can you show us an explain analyse? Here is the explain with my initial index: create index long_transformation2_index on indexed_table (this_is_a_long_transformation(data2)); ------------------------------------- Seq Scan on indexed_table (cost=0.00..26791.00 rows=33333 width=12) (actual time=0.158..5379.933 rows=49740 loops=1) Filter: (data1 > this_is_a_long_transformation(data2)) Total runtime: 5606.855 ms ------------------------------------- > What I notice off-hand is that you don't appear to have an index on > data1, so Postgres doesn't know for which rows that is > > some_immutable_function(data2). I tried adding an index on data1: create index long_transformation1_index on indexed_table (data1); create index long_transformation2_index on indexed_table (this_is_a_long_transformation(data2)); But I still have an sequential scan: ------------------------------------- Seq Scan on indexed_table (cost=0.00..26791.00 rows=33333 width=12) (actual time=0.199..5284.322 rows=49739 loops=1) Filter: (data1 > this_is_a_long_transformation(data2)) Total runtime: 5513.676 ms ------------------------------------- ----------------------------------------------------------------------- Philippe Lang Web : www.attiksystem.ch Attik System Email : philippe.lang@xxxxxxxxxxxxxx rte de la Fonderie 2 Phone : +41 26 422 13 75 1700 Fribourg Mobile : +41 79 351 49 94 Switzerland Fax : +41 26 422 13 76 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
