On 27 November 2017 at 16:35, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I wrote:
>> Dean Rasheed <dean.a.rasheed@gmail.com> writes:
>>> A separate point -- it might be marginally more efficient to have the
>>> work of rewriteTargetListUD() done after expand_targetlist() to avoid
>>> the possible renumbering of the resjunk entries.
>
>> Hm. It wouldn't save a lot, but yeah, doing it in this order seems
>> a bit silly when you put it like that.
>
> On looking closer, the reason it's like that in Fujita-san's patch
> is to minimize the API churn seen by FDW AddForeignUpdateTargets
> functions, specifically whether they see a tlist that's before or
> after what expand_targetlist() does. I'm doubtful that the
> potential savings is worth taking risks there. In particular,
> it seems like a good thing that expand_targetlist() verifies the
> correct tlist ordering *after* the FDW function has acted.
> So now my inclination is to leave this alone.
>
Ah yes, that seems like a worthwhile check to keep. Never mind then.
Regards,
Dean
