| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Amit Kapila <amit(dot)kapila(at)huawei(dot)com> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Improving our clauseless-join heuristics |
| Date: | 2012-04-18 05:06:29 |
| Message-ID: | 20977.1334725589@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Amit Kapila <amit(dot)kapila(at)huawei(dot)com> writes:
>> I might still be misunderstanding, but I think what you are suggesting
>> is that in the loop in make_rels_by_clause_joins, if we find that the
>> old_rel doesn't have a join clause/restriction with the current
>> other_rel, we check to see whether other_rel has any join clauses at
>> all, and force the join to occur anyway if it doesn't.
> It is on similar lines, but the only difference is that it will try to join
> old_rel with other_rel list incase
> old_rel is not able to join with any of other_rel in the list with proper
> join clause between them.
I'm afraid I'm still not following you very well. Perhaps you could
submit a proposed patch?
regards, tom lane
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