Re: fixing subplan/subquery confusion - Mailing list pgsql-hackers

From Tom Lane
Subject Re: fixing subplan/subquery confusion
Date
Msg-id 17721.1467082544@sss.pgh.pa.us
Whole thread Raw
In response to Re: fixing subplan/subquery confusion  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: fixing subplan/subquery confusion  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
Amit Kapila <amit.kapila16@gmail.com> writes:
> I had couple of questions [1] related to that patch.  See if you find
> those as relevant?

I do not think those cases are directly relevant: you're talking about
appendrels not single, unflattened RTE_SUBQUERY rels.

In the subquery case, my view of how it ought to work is that Paths coming
up from the subquery would be marked as not-parallel-safe if they contain
references to unsafe functions.  It might be that that doesn't happen for
free, but my guess is that it would already work that way given a change
similar to what I proposed.

In the appendrel case, I tend to agree that the easiest solution is to
scan all the children of the appendrel and just mark the whole thing as
not consider_parallel if any of them have unsafe functions.
        regards, tom lane



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