Re: select few fields as a single field

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От Jochem van Dieten
Тема Re: select few fields as a single field
Дата
Msg-id 3C3D9067.6050504@oli.tudelft.nl
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Ответ на select few fields as a single field  (Roman Gavrilov <romio@il.aduva.com>)
Список pgsql-general
Roman Gavrilov wrote:

> Ok I think after all I will use view.
> However i'll have to join many tables in the view want it slow the
> performance dramatically ?
> I run explain on the view and got
> explain select event_id from get_event;
> NOTICE:  QUERY PLAN:
> Merge Join  (cost=376812.28..389383.78 rows=10000000 width=60)
> when the biggest table contains 40 records only
>
> when explain select event_id from intelligence;  :
> NOTICE:  QUERY PLAN:
> Seq Scan on intelligence  (cost=0.00..20.00 rows=1000 width=4)


How acurate are these numbers for the amount of returned rows? Could you
run a VACUUM ANALYZE and try again?

Jochem


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