| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Mike Mascari <mascarm(at)mascari(dot)com> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Slow execution time when querying view with WHERE clause |
| Date: | 2004-11-23 17:54:05 |
| Message-ID: | 28237.1101232445@sss.pgh.pa.us |
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| Lists: | pgsql-performance |
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?
Are you sure you ANALYZEd this table recently?
regards, tom lane
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