Re: Join push-down support for foreign tables

2015-03-04 17:00 GMT+09:00 Etsuro Fujita <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp>:
> On 2015/03/03 21:34, Shigeru Hanada wrote:
>>
>> I rebased "join push-down" patch onto Kaigai-san's Custom/Foreign Join
>> v6 patch.
>
>
> Thanks for the work, Hanada-san and KaiGai-san!
>
> Maybe I'm missing something, but did we agree to take this approach, ie,
> "join push-down" on top of custom join? There is a comment ahout that [1].
> I just thought it'd be better to achieve a consensus before implementing the
> feature further.

As Kaigai-san says, foreign join push-down is beside custom scan, and
they are on the custom/foreign join api patch.

>
>> but still the patch
>> has an issue about joins underlying UPDATE or DELETE. Now I'm working
>> on fixing this issue.
>
>
> Is that something like "UPDATE foo ... FROM bar ..." where both foo and bar
> are remote? If so, I think it'd be better to push such an update down to
> the remote, as discussed in [2], and I'd like to work on that together!

A part of it, perhaps. But at the moment I see many issues to solve
around pushing down complex UPDATE/DELETE. So I once tightened the
restriction, that joins between foreign tables are pushed down only if
they are part of SELECT statement. Please see next v4 patch I'll post
soon.

>
> Sorry for having been late for the party.
>
> Best regards,
> Etsuro Fujita
>
> [1] http://www.postgresql.org/message-id/23343.1418658355@sss.pgh.pa.us
> [2] http://www.postgresql.org/message-id/31942.1410534785@sss.pgh.pa.us

--
Shigeru HANADA