| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>, Kuntal Ghosh <kuntalghosh(dot)2007(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: [HACKERS] parallelize queries containing initplans |
| Date: | 2017-11-14 16:00:14 |
| Message-ID: | 19264.1510675214@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Tue, Nov 14, 2017 at 12:00 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)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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