Re: [PGSQL v8.2.5] Similar queries behave differently

"Reg Me Please" <regmeplease@gmail.com> writes:

>                ->  Seq Scan on tt_elem  (cost=0.00..29.40 rows=1940 width=8)
>                                         (actual time=0.012..0.013 rows=1 loops=1)

The discrepancy etween the estimated rows and actual rows makes me think
you've not analyzed this table in a long time. It's probably best to analyze
the whole database to have a consistent set of statistics and to catch any
other old table stats.

There could be other misestimations based due to Postgres limitations but
first fix the out of date stats and re-post both plans.

--
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com