Horton

Re: Asynchronous Append on postgres_fdw nodes.

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: pryzby@telsasoft.com
Cc: a.lepikhov@postgrespro.ru, etsuro.fujita@gmail.com, movead.li@highgo.ca, pgsql-hackers@lists.postgresql.org
Date: 2020-08-20T07:36:08Z
Lists: pgsql-hackers

Attachments

At Wed, 19 Aug 2020 23:25:36 -0500, Justin Pryzby <pryzby@telsasoft.com> wrote in 
> On Thu, Jul 02, 2020 at 11:14:48AM +0900, Kyotaro Horiguchi wrote:
> > As the result of a discussion with Fujita-san off-list, I'm going to
> > hold off development until he decides whether mine or Thomas' is
> > better.
> 
> The latest patch doesn't apply so I set as WoA.
> https://commitfest.postgresql.org/29/2491/

Thanks. This is rebased version.

At Fri, 14 Aug 2020 13:29:16 +1200, Thomas Munro <thomas.munro@gmail.com> wrote in 
> Either way, we definitely need patch 0001.  One comment:
> 
> -CreateWaitEventSet(MemoryContext context, int nevents)
> +CreateWaitEventSet(MemoryContext context, ResourceOwner res, int nevents)
> 
> I wonder if it's better to have it receive ResourceOwner like that, or
> to have it capture CurrentResourceOwner.  I think the latter is more
> common in existing code.

There's no existing WaitEventSets belonging to a resowner. So
unconditionally capturing CurrentResourceOwner doesn't work well. I
could pass a bool instead but that make things more complex.

Come to think of "complex", ExecAsync stuff in this patch might be
too-much for a short-term solution until executor overhaul, if it
comes shortly. (the patch of mine here as a whole is like that,
though..). The queueing stuff in postgres_fdw is, too.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Improve comments for trivial_subqueryscan().

  2. Disable asynchronous execution if using gating Result nodes.

  3. Allow asynchronous execution in more cases.

  4. Doc: Further update documentation for asynchronous execution.

  5. Fix rescanning of async-aware Append nodes.

  6. Doc: Update documentation for asynchronous execution.

  7. Fix EXPLAIN ANALYZE for async-capable nodes.

  8. Minor code cleanup in asynchronous execution support.

  9. Adjust input value to WaitEventSetWait() in ExecAppendAsyncEventWait().

  10. Add support for asynchronous execution.