From: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>, Kuntal Ghosh <kuntalghosh(dot)2007(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: parallelize queries containing initplans |
Date: | 2017-10-05 17:16:17 |
Message-ID: | CAA4eK1KfqKrMjbsXpVmHT=FeQ=M8WmE6C1sV6b6aL3ZBie3gLQ@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Thu, Oct 5, 2017 at 6:08 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Thu, Oct 5, 2017 at 5:52 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> Now, unless, I am missing something here, it won't be possible to
>> detect params in such cases during forming of join rels and hence we
>> need the tests in generate_gather_paths. Let me know if I am missing
>> something in this context or if you have any better ideas to make it
>> work?
>
> Hmm, in a case like this, I think we shouldn't need to detect it. The
> Var is perfectly parallel-safe, the problem is that we can't use a
> not-safe plan for the inner rel. I wonder why that's happening
> here...
>
It is because the inner rel (Result Path) contains a reference to a
param which appears to be at the same query level. Basically due to
changes in max_parallel_hazard_walker().
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2017-10-05 17:25:48 | Re: Optimise default partition scanning while adding new partition |
Previous Message | Nico Williams | 2017-10-05 17:16:05 | Re: postgres_fdw super user checks |