Horton

Re: ParallelFinish-hook of FDW/CSP (Re: Steps inside ExecEndGather)

Claudio Freire <klaussfreire@gmail.com>

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From: Claudio Freire <klaussfreire@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Kohei KaiGai <kaigai@kaigai.gr.jp>, Kouhei Kaigai <kaigai@ak.jp.nec.com>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-02-24T16:40:49Z
Lists: pgsql-hackers 
On Fri, Feb 24, 2017 at 1:24 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Fri, Feb 24, 2017 at 7:29 PM, Kohei KaiGai <kaigai@kaigai.gr.jp> wrote:
>> This attached patch re-designed the previous v2 according to Robert's comment.
>> All I had to do is putting entrypoint for ForeignScan/CustomScan at
>> ExecShutdownNode,
>> because it is already modified to call child node first, earlier than
>> ExecShutdownGather
>> which releases DSM segment.
>
> Aside from the documentation, which needs some work, this looks fine
> to me on a quick read.

LGTM too.

You may want to clarify in the docs when the hook is called in
relation to other hooks too.

Commits

  1. Allow custom and foreign scans to have shutdown callbacks.

  2. Shut down Gather's children before shutting down Gather itself.