Re: Slow execution time when querying view with WHERE clause - Mailing list pgsql-performance

From Tom Lane
Subject Re: Slow execution time when querying view with WHERE clause
Date
Msg-id 28237.1101232445@sss.pgh.pa.us
Whole thread Raw
In response to Slow execution time when querying view with WHERE clause  (Mike Mascari <mascarm@mascari.com>)
Responses Re: Slow execution time when querying view with WHERE clause  (Mike Mascari <mascarm@mascari.com>)
List pgsql-performance
Mike Mascari <mascarm@mascari.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?
Are you sure you ANALYZEd this table recently?

            regards, tom lane

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