Re: parallelize queries containing subplans
Amit Kapila <amit.kapila16@gmail.com>
From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-01-16T15:43:15Z
Lists: pgsql-hackers
Attachments
- pq_pushdown_subplan_v3.patch (application/octet-stream) patch v3
- (unnamed) (text/plain)
On Thu, Jan 12, 2017 at 7:56 PM, Amit Kapila <amit.kapila16@gmail.com> wrote: > On Thu, Jan 12, 2017 at 8:51 AM, Robert Haas <robertmhaas@gmail.com> wrote: >> On Wed, Jan 11, 2017 at 9:58 PM, Amit Kapila <amit.kapila16@gmail.com> wrote: >>> The other alternative is to remember this information in SubPlan. We >>> can retrieve parallel_safe information from best_path and can use it >>> while generating SubPlan. The main reason for storing it in the plan >>> was to avoid explicitly passing parallel_safe information while >>> generating SubPlan as plan was already available at that time. >>> However, it seems there are only two places in code (refer >>> build_subplan) where this information needs to be propagated. Let me >>> know if you prefer to remember the parallel_safe information in >>> SubPlan instead of in Plan or if you have something else in mind? >> >> I think we should try doing it in the SubPlan, at least, and see if >> that comes out more elegant than what you have at the moment. >> > > Okay, done that way. I have fixed the review comments raised by Dilip > as well and added the test case in attached patch. > After commit-ab1f0c8, this patch needs a rebase. Attached find rebased version of the patch. Thanks to Kuntal for informing me offlist that this patch needs rebase. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
Commits
-
Allow parallel workers to execute subplans.
- 5e6d8d2bbbca 10.0 landed