Re: parallelize queries containing subplans
Dilip Kumar <dilipbalaut@gmail.com>
From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-01-12T06:41:39Z
Lists: pgsql-hackers
On Thu, Jan 12, 2017 at 9:22 AM, Amit Kapila <amit.kapila16@gmail.com> wrote: > Valid point, but I think we can avoid that by returning false after > foreach(..) loop. I think one improvement could be that instead of > manually checking the parallel safety of each subplan, we can > recursively call max_parallel_hazard_walker for each subplan. I agree that this way we can avoid the problem what I mentioned. > > >> But, more than that it will be cleaner to not >> handle AlternativeSubPlan here unless there is some strong reason? >> > > Yeah, the reason is to avoid unnecessary recursion. Also, in all > other places in the code, we do handle both of them separately, refer > cost_qual_eval_walker for somewhat similar usage. ok. -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
Commits
-
Allow parallel workers to execute subplans.
- 5e6d8d2bbbca 10.0 landed