Re: zero performance on query

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От Steinar H. Gunderson
Тема Re: zero performance on query
Дата
Msg-id 20051026103051.GB1742@uio.no
обсуждение исходный текст
Ответ на zero performance on query  (Sidar López Cruz <sidarlopez@hotmail.com>)
Список pgsql-performance
On Tue, Oct 25, 2005 at 10:26:43PM -0600, Sidar López Cruz wrote:
> look at this:
> select count(*) from fotos where archivo not in (select archivo from
> archivos)
> Aggregate  (cost=4899037992.36..4899037992.37 rows=1 width=0)
> ->  Seq Scan on fotos  (cost=22598.78..4899037338.07 rows=261716 width=0)
>       Filter: (NOT (subplan))
>       SubPlan
>         ->  Materialize  (cost=22598.78..39304.22 rows=805344 width=58)
>               ->  Seq Scan on archivos  (cost=0.00..13141.44 rows=805344
> width=58)

Now, this is interesting; it seems to trigger exactly the same oddity as my
query did (at least one of them; the materialized sequential scan).

/* Steinar */
--
Homepage: http://www.sesse.net/

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