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Date: Sun, 23 Jul 2023 15:20:21 +0300
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Subject: Re: Making Vars outer-join aware
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To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Richard Guo
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From: "Anton A. Melnikov" <aamelnikov@inbox.ru>
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On 08.06.2023 19:58, Tom Lane wrote:
> I think the right thing here is not either of your patches, but
> to tweak adjust_relid_set() to not fail on negative oldrelid.
> I'll go make it so.

Thanks! This fully solves the problem with ChangeVarNodes() that i wrote above.


> Hmm.  That implies that you're changing plan data structures around after
> setrefs.c, which doesn't seem like a great design to me --- IMO that ought
> to happen in PlanCustomPath, which will still see the original varnos.

My further searchers led to the fact that it is possible to immediately set the
necessary varnos during custom_scan->scan.plan.targetlist creation and leave the
сustom_scan->custom_scan_tlist = NIL rather than changing them later using ChangeVarNodes().
This resulted in a noticeable code simplification.
Thanks a lot for pointing on it!

Sincerely yours,

-- 
Anton A. Melnikov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company