Re: Optimization for updating foreign tables in Postgres FDW

On Wed, Apr 13, 2016 at 11:24 AM, Etsuro Fujita
<fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> On 2016/04/13 3:14, Robert Haas wrote:
>>
>> I'm wondering why we are fixing this specific case and not any of the
>> other calls to PQexec() or PQexecParams() in postgres_fdw.c.
>>
>> I mean, many of those instances are cases where the query isn't likely
>> to run for very long, but certainly "FETCH %d FROM c%u" is in theory
>> just as bad as the new code introduced in 9.6. In practice, it
>> probably isn't, because we're probably only fetching 50 rows at a time
>> rather than potentially a lot more, but if we're fixing this code up
>> to be interrupt-safe, maybe we should fix it all at the same time.
>> Even for the short-running queries like CLOSE and DEALLOCATE, it seems
>> possible that there could be a network-related hang which you might
>> want to interrupt.
>
>
> Actually, I was wondering, too, but I didn't propose that because, as far as
> I know, there are no reports from the field. But I agree with you.

For something that is HEAD-only that's a great idea to put everything
into the same flag like that.
--
Michael