Re: SDP query optimizer

On 2013-03-22 20:35:43 -0300, Adriano Lange wrote:
> Hi all,
>
> I have developed a new query optimizer for PostgreSQL and I would like to
> share it with the community. The optimizer's name is Sampling and Dynamic
> Programming (SDP). I put it into a plugin developed some years ago, named
> LJQO:
>
> https://github.com/alange0001/ljqo.git
>
> This plugin was configured to compile only against PostgreSQL 9.2. However,
> I guess it may be easily adjusted for other versions of PostgreSQL.
>
> I would be glad for any feedback about SDP or even about LJQO.
>
> I have some numbers about the SDP in comparison with GEQO. If interested,
> see a diff between the two ".out2" files attached. The schema and query are
> from a previous email posted by Andres Freund in this list.

I just want to mention that unless you skew the statistics for the individual
tables from their empty/default state this mostly measures a pretty degenerate
case where optima are very rare and not very differentiated. Thats a useful
thing to test, but not to have as the target to optimize for.
So it might be interesting to run that thing with some table
stats/contents stats set up.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services