Re: Slow execution time when querying view with WHERE clause

--- Mike Mascari <mascarm(at)mascari(dot)com> escribió:
> Tom Lane wrote:
> > Mike Mascari <mascarm(at)mascari(dot)com> writes:
> >
> >>When I query the view with a simple filter, I get:
> >
> >
> >>explain analyze select * from p_areas where
> deactive is null;
> >
> >
> > The problem seems to be here:
> >
> >
> >> -> Seq Scan on _areas a (cost=0.00..2.48
> rows=1 width=163) (actual time=0.037..0.804 rows=48
> loops=1)
> >> Filter: (deactive IS NULL)
> >
> >
> > Why is it so completely off about the selectivity
> of the IS NULL clause?

null values are not indexable, is that your question?
If it is your question then create a partial index
with where deactive is null.

regards,
Jaime Casanova

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