Re: GSoC idea - Simulated annealing to search for query plans

Thank you a lot for your feedback. I searched a lot about GEQO,
but I didn't find information about any earlier attempts.
I'm happy to know that this is important for Postgres.

I'm really interested in this project, so I just need to estimate if I can
handle it.
Now I will spend some time with SAIO and GEQO to find it out.

Best,
Grzegorz

2015-02-27 16:29 GMT+01:00 Jan Urbański <wulczer(at)wulczer(dot)org>:

>
> Josh Berkus writes:
>
> > On 02/26/2015 05:50 PM, Fabrízio de Royes Mello wrote:
> >>
> >> On Thu, Feb 26, 2015 at 10:27 PM, Andres Freund <andres(at)2ndquadrant(dot)com
> >> <mailto:andres(at)2ndquadrant(dot)com>> wrote:
> >>>
> >>> On 2015-02-26 20:23:33 -0500, Tom Lane wrote:
> >>> >
> >>> > I seem to recall somebody demo'ing a simulated-annealing GEQO
> >> replacement
> >>> > at PGCon a couple years back. It never got to the point of being a
> >>> > submitted patch though.
> >>>
> >>> Yea, it was Jan Urbański (CCed).
> >>>
> >>
> >> And the project link: https://github.com/wulczer/saio
> >
> > So what w'ere saying, Grzegorz, is that we would love to see someone
> > pick this up and get it to the point of making it a feature as a GSOC
> > project. I think if you can start from where Jan left off, you could
> > actually complete it.
>
> Sorry, late to the party.
>
> Yes, I wrote a GEQO replacement that used simulated annealing for my Master
> thesis. It got to a point where it was generating plans similar to what
> GEQO
> outputs for small queries and better plans for very large ones.
>
> The thesis itself is here: https://wulczer.org/saio.pdf and the linked
> GitHub
> repo contains source for the PGCon presentation, which gives a higher-level
> overview.
>
> The big problem turned out to be writing the step function that generates
> a new
> join order from a previous one. Look for the "Simulated Annealing
> challenges"
> and "Moves generator" chapters in my thesis, which are the only interesting
> ones :)
>
> If you'd like to pick up where I left, I'd be more than happy to help in
> any
> ways I can.
>
> Best,
> Jan
>