On Sun, Jul 29, 2007 at 01:44:23PM -0300, Bruno Rodrigues Siqueira wrote: > EXPLAIN > ANALYZE > select > to_char(data_encerramento,'mm/yyyy') as opcoes_mes, > to_char(data_encerramento,'yyyy-mm') as ordem from detalhamento_bas > where > > data_encerramento >= '01/12/2006' and > data_encerramento < '01/02/2007' > > GROUP BY opcoes_mes, ordem > ORDER BY ordem DESC > > **************************************************************************** > > QUERY PLAN > Sort (cost=219113.10..219113.10 rows=4 width=8) (actual > time=10079.212..10079.213 rows=2 loops=1) > Sort Key: to_char(data_encerramento, 'yyyy-mm'::text) > -> HashAggregate (cost=219113.09..219113.09 rows=4 width=8) (actual > time=10079.193..10079.195 rows=2 loops=1) > -> Seq Scan on detalhamento_bas (cost=0.00..217945.41 rows=2335358 > width=8) (actual time=0.041..8535.792 rows=2335819 loops=1) > Filter: ((data_encerramento >= '2006-12-01 > 00:00:00'::timestamp without time zone) AND (data_encerramento < '2007-02-01 > 00:00:00'::timestamp without time zone)) > Total runtime: 10079.256 ms > > Strange!!! Why does the index not works? It's unlikely that it's going to be faster to index scan 2.3M rows than to sequential scan them. Try setting enable_seqscan=false and see if it is or not. -- Decibel!, aka Jim Nasby decibel@xxxxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
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