| From: | Ben <bench(at)silentmedia(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: full outer join performance |
| Date: | 2005-09-13 18:56:28 |
| Message-ID: | 432720DC.8030102@silentmedia.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
I see. I think I'm going to restructure my logic so I won't have to use
the outer join after all, but thanks for the pointers anyway.
Tom Lane wrote:
>Ben <bench(at)silentmedia(dot)com> writes:
>
>
>>Hrm, as I understand that page, there's not much that can be done about
>>the join order for outer joins. At least, not when there's on 3 tables
>>and 1 outer join involved. Am I missing something?
>>
>>
>
>Without knowing what you want the query to do, it's difficult to say if
>it's OK to rearrange the join order.
>
>Frequently it's OK to rearrange the join order even without risking any
>change in the query results, but PG doesn't currently have any smarts
>about that, so you have to do it manually by changing the query.
>
> regards, tom lane
>
>
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