Re: [HACKERS] parallelize queries containing initplans

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От Tom Lane
Тема Re: [HACKERS] parallelize queries containing initplans
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Msg-id 19264.1510675214@sss.pgh.pa.us
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Ответ на Re: [HACKERS] parallelize queries containing initplans  (Robert Haas <robertmhaas@gmail.com>)
Ответы Re: [HACKERS] parallelize queries containing initplans  (Robert Haas <robertmhaas@gmail.com>)
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Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Nov 14, 2017 at 12:00 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> Am I missing something?  Do you have some test or shape of the plan in
>> mind which can cause a problem?

> The problem would happen if the plan for InitPlan $1 in the above
> example itself referenced a parameter from an upper query level, and
> the value of that parameter changed, and then this section of the plan
> tree was rescanned.  I'm not sure I can write a query like that
> off-hand, but I think it's possible to do so.

Yeah, I'm sure it is.  I have a vague recollection that there might be
existing regression test cases exercising such things, though I won't
swear to that.  The "orderstest" bit in subselect.sql looks like it
might be meant to do that...
        regards, tom lane


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