Rhaoni, First off, thanks for posting such complete info.
> ... gsames00.ano_mes = to_char(ftnfco00.data_emissao,'YYYYMM') AND ... > > ftnfco00.data_emissao is a timestamp. When I run the explain analyze it says: > > ... > -> Seq Scan on gsames00 (cost=100000000.00..100000006.72 rows=372 width=10) > (actual time=0.01..0.96 rows=372 loops=19923) > ... Your problem is that you're comparing against a calculated expression based on ftnfco00, which is being filtered in about 18 other ways. As a result, the planner doesn't know what to estimate (see the cost estimate of 100000000, which is a "blind guess" values) and goes for a seq scan. Can I ask you to try this workaround, to create an expressional index on ftnfco00 (assuming that data_emmisao is of type DATE) create function date_to_yyyymm( date ) returns text as 'select to_char($1, ''YYYYMM''); ' language sql immutable strict; create index idx_data_yyyymm on ftnfco00(date_to_yyyymm(data_emmisao)); -- -Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
