Re: Missed index opportunity for outer join?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Missed index opportunity for outer join?
Date: 2005-12-06 21:24:59
Message-ID: 16502.1133904299@sss.pgh.pa.us
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Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com> writes:
> Tom Lane wrote:
>> In this explanation, the reason for the change in plans over time could
>> be a change in the statistics for the other table. Is "facets" more
>> dynamic than "point_features"?

> Facets is a big table with rather odd distributions of values.
> Many of the values in the indexed columns show up only
> once, others show up hundreds-of-thousands of times. Perhaps
> an analyze ran and just randomly sampled differently creating
> different stats on that table?

If you have background tasks doing ANALYZEs then this explanation seems
plausible enough. I'm willing to accept it anyway ...

regards, tom lane

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