Re: GEQO: ERX

Hi

Tobias Zahn escreveu:
> Hello Adriano,
> thank you very much for posting your patch. I think it will help to make
> further work easier, too. I hope you don't mind when I ask you some
> questions.
> 
> When you said that this new approach is worse or equal than GEQO, did
> you refer to performance or to the quality of results?

Not exactly this approach, but the implemented (and not configured) 
algorithm was worse than GEQO in a little test made. I just used a 
sequence of 8 executions of a query with 18 relations for each 
algorithm. The costs generated by GEQO was little better than 2PO, in 
average and standard deviation. But 8 executions and 1 query don't prove 
anything. I want to make some further tests, but this little difference 
seems good for me.

> Why do you think that compressed annealing might be the better approach?

I don't think if compressed annealing is better or not. I don't read 
about it yet.

However, an optimizer can be better in a context but worse in another.

Regards,
Adriano