Re: Postgres with pthread

On 7 December 2017 at 01:17, Andres Freund <andres(at)anarazel(dot)de> wrote:

>
> > I think you've done us a very substantial service by pursuing
> > this far enough to get some quantifiable performance results.
> > But now that we have some results in hand, I think we're best
> > off sticking with the architecture we've got.
>
> I don't agree.
>
> I'd personally expect that an immediate conversion would result in very
> little speedup, a bunch of code deleted, a bunch of complexity
> added. And it'd still be massively worthwhile, to keep medium to long
> term complexity and feature viability in control.
>

Personally I think it's a pity we didn't land up here before the
foundations for parallel query went in - DSM, shm_mq, DSA, etc. I know the
EDB folks at least looked into it though, and presumably there were good
reasons to go in this direction. Maybe that was just "community will never
accept threaded conversion" at the time, though.

Now we have quite a lot of homebrew infrastructure to consider if we do a
conversion.

That said, it might in some ways make it easier. shm_mq, for example, would
likely convert to a threaded backend with minimal changes to callers, and
probably only limited changes to shm_mq its self. So maybe these
abstractions will prove to have been a win in some ways. Except DSA, and
even then it could serve as a transitional API...

--
Craig Ringer http://www.2ndQuadrant.com/
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