Re: How can I make PosgreSQL use an Index ?

Rhaoni Chiu Pereira <rhaoni@sistemica.info> writes:
>   When I run a explain analyze with this where clause:
>    ... gsames00.ano_mes = to_char(ftnfco00.data_emissao,'YYYYMM') AND ...
> ...
>  ->  Seq Scan on gsames00  (cost=100000000.00..100000006.72 rows=372 width=10)
> (actual time=0.01..0.96 rows=372 loops=19923)
> ...

If you're not going to show us the whole query and the whole EXPLAIN
output, you're going to get equally incomplete answers.  I will say
though that forcing an index instead of a seqscan on a 372-row table
isn't likely to be a magic bullet.  You probably need a better join
plan.

Please post fuller details on pgsql-performance.  You might save some
time by reading the posting tips first ...
http://techdocs.postgresql.org/guides/SlowQueryPostingGuidelines

            regards, tom lane