Re: INDEX and JOINs - Mailing list pgsql-general

From Reg Me Please
Subject Re: INDEX and JOINs
Date
Msg-id 200710270837.59909.regmeplease@gmail.com
Whole thread Raw
In response to Re: INDEX and JOINs  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: INDEX and JOINs  (Andreas Kretschmer <akretschmer@spamfence.net>)
List pgsql-general
Il Friday 26 October 2007 15:18:04 Tom Lane ha scritto:
> Reg Me Please <regmeplease@gmail.com> writes:
> >>> (cost=3.95..382140.91 rows=274709 width=91) (actual
> >>> time=1.929..57713.305 rows=92 loops=1)
> >>> Hash Cond: (t_dati.camp_id = t_campi.camp_id)
>
> I think the reason it doesn't want to use an indexed join is the large
> estimate of the number of join result rows.  You need to try to get that
> number down to something nearer the reality.  Increasing the statistics
> target for the larger table might help.
>
>             regards, tom lane

How can I "Increasing the statistics target for the larger table"?
I'ìm sorry for asking, but I'm not that deep into RDBMS.

Thanks.


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