Re: postgres_fdw join pushdown (was Re: Custom/Foreign-Join-APIs)

On Thu, Dec 10, 2015 at 11:20 PM, Robert Haas <robertmhaas@gmail.com> wrote:

On Tue, Dec 8, 2015 at 6:40 AM, Etsuro Fujita
<fujita.etsuro@lab.ntt.co.jp> wrote:
> IMO I want to see the EvalPlanQual fix in the first version for 9.6.

+1.

I think there is still a lot functionality that is offered without EvalPlanQual fix. As long as we do not push joins when there are RowMarks involved, implementation of that hook is not required. We won't be able to push down joins for DMLs and when there are FOR SHARE/UPDATE clauses in the query. And there are huge number of queries, which will be benefitted by the push down even without that support. There's nothing in this patch, which comes in way of implementing the EvalPlanQual fix. It can be easily added after committing the first version. On the other hand, getting minimal (it's not really minimal, it's much more than that) support for postgres_fdw support committed opens up possibility to work on multiple items (as listed in my mail) in parallel.