Re: Optimization for updating foreign tables in Postgres FDW

On 13 May 2015 at 04:10, Etsuro Fujita <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> On 2015/05/13 0:55, Stephen Frost wrote:
>>
>> Etsuro,
>>
>> * Etsuro Fujita (fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp) wrote:
>>>
>>> Here is an updated version. In this version, the bug has been
>>> fixed, but any regression tests for that hasn't been added, because
>>> I'm not sure that the above way is a good idea and don't have any
>>> other ideas.
>>>
>>> The EXPLAIN output has also been improved as discussed in [1].
>>
>>
>> While the EXPLAIN output changed, the structure hasn't really changed
>> from what was discussed previously and there's not been any real
>> involvment from the core code in what's happening here.
>>
>> Clearly, the documentation around how to use the FDW API hasn't changed
>> at all and there's been no additions to it for handling bulk work.
>> Everything here continues to be done inside of postgres_fdw, which
>> essentially ignores the prescribed "Update/Delete one tuple" interface
>> for ExecForeignUpdate/ExecForeignDelete.
>>
>> I've spent the better part of the past two days trying to reason my way
>> around that while reviewing this patch and I haven't come out the other
>> side any happier with this approach than I was back in
>> 20140911153049(dot)GC16422(at)tamriel(dot)snowman(dot)net(dot)
>>
>> There are other things that don't look right to me, such as what's going
>> on at the bottom of push_update_down(), but I don't think there's much
>> point going into it until we figure out what the core FDW API here
>> should look like. It might not be all that far from what we have now,
>> but I don't think we can just ignore the existing, documented, API.
>
>
> OK, I'll try to introduce the core FDW API for this (and make changes to the
> core code) to address your previous comments.
>
> Thanks for taking the time to review the patch!

Fujita-san,

I'm a bit behind in reading up on this, so maybe it's been covered
since, but is there a discussion of this API on another thread, or a
newer patch available?

Thanks

Thom