Re: postgres_fdw join pushdown (was Re: Custom/Foreign-Join-APIs)
| От | Ashutosh Bapat |
|---|---|
| Тема | Re: postgres_fdw join pushdown (was Re: Custom/Foreign-Join-APIs) |
| Дата | |
| Msg-id | CAFjFpRdPDif-+6XDU4ybgrfkNLH3f-eq4DXfNCsX7OD+ABy0oQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: postgres_fdw join pushdown (was Re: Custom/Foreign-Join-APIs) (Robert Haas <robertmhaas@gmail.com>) |
| Ответы |
Re: postgres_fdw join pushdown (was Re:
Custom/Foreign-Join-APIs)
Re: postgres_fdw join pushdown (was Re: Custom/Foreign-Join-APIs) |
| Список | pgsql-hackers |
On Thu, Dec 10, 2015 at 11:20 PM, Robert Haas <robertmhaas@gmail.com> wrote:
I am not saying that we do not need EvalPlanQual fix in 9.6. But it's not needed in the first cut. If we get the first cut in first couple of months of 2016, there's plenty of room for the fix to go in 9.6. It would be really bad situation if we could not get postgres_fdw join pushdown supported in 9.6 because EvalPlanQual hook could not be committed while the rest of the code is ready. EvalPlanQual fix in core was being discussed since April 2015. It took 8 months to get that fixed. Hopefully we won't need that long to implement the hook in postgres_fdw, but that number says something about the complexity of the feature.
-- On Tue, Dec 8, 2015 at 6:40 AM, Etsuro FujitaI 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.
<fujita.etsuro@lab.ntt.co.jp> wrote:
> IMO I want to see the EvalPlanQual fix in the first version for 9.6.
+1.
I am not saying that we do not need EvalPlanQual fix in 9.6. But it's not needed in the first cut. If we get the first cut in first couple of months of 2016, there's plenty of room for the fix to go in 9.6. It would be really bad situation if we could not get postgres_fdw join pushdown supported in 9.6 because EvalPlanQual hook could not be committed while the rest of the code is ready. EvalPlanQual fix in core was being discussed since April 2015. It took 8 months to get that fixed. Hopefully we won't need that long to implement the hook in postgres_fdw, but that number says something about the complexity of the feature.
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company
В списке pgsql-hackers по дате отправления: