| From: | Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: WIP: Upper planner pathification |
| Date: | 2016-03-09 12:05:03 |
| Message-ID: | CAPpHfdtV4B_cT9kz4X4rjwc3xw7MKyW2nME5cD5ifqzOvmmDaw@mail.gmail.com |
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| Lists: | pgsql-hackers |
Hi, Tom!
I have a question about Sort path. AFAICS this question wasn't mentioned in
the upthread discussion.
We're producing Sort plans in two ways: from explicit Sort paths, and from
other paths which implicitly assumes sorting (like MergeJoin path).
Would it be better to produce Sort plan only from explicit Sort path? Thus,
MergeJoin path would add explicit children Sort paths. That would be more
unified way.
I ask about this from point of view of my "Partial Sort" patch. The absence
of implicit sorts would help to make this patch more simple and clean.
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
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