Re: BUG #16583: merge join on tables with different DB collation behind postgres_fdw fails

Etsuro Fujita <etsuro(dot)fujita(at)gmail(dot)com> writes:
> On Thu, Jul 15, 2021 at 4:17 AM Ibrar Ahmed <ibrar(dot)ahmad(at)gmail(dot)com> wrote:
>> On Wed, Jul 14, 2021 at 1:41 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Seems to just need an update of the expected-file to account for test
>>> cases added recently. (I take no position on whether the new results
>>> are desirable; some of these might be breaking the intent of the case.
>>> But this should quiet the cfbot anyway.)

>> The test case was added by commit "Add support for asynchronous execution"
>> "27e1f14563cf982f1f4d71e21ef247866662a052" by Etsuro Fujita. He can comment
>> whether the new results are desirable or not.

> The new results aren't what I intended. I'll update the patch to
> avoid that by modifying the original test cases properly, if there are
> no objections.

Please follow up on that sometime? In the meantime, here is a rebase
over aa769f80e and 2dc53fe2a, to placate the cfbot.

The real reason that this hasn't gotten committed is that I remain
pretty uncomfortable about whether it's an acceptable solution to
the problem. Suddenly asking people to plaster COLLATE clauses
on all their textual remote columns seems like a big compatibility
gotcha. However, I lack any ideas about a less unpleasant solution.

regards, tom lane