| From: | Reg Me Please <regmeplease(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: INDEX and JOINs |
| Date: | 2007-10-27 06:37:59 |
| Message-ID: | 200710270837.59909.regmeplease@gmail.com |
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| Thread: | |
| Lists: | pgsql-general |
Il Friday 26 October 2007 15:18:04 Tom Lane ha scritto:
> Reg Me Please <regmeplease(at)gmail(dot)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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