Re: Improving GEQO - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Improving GEQO
Date
Msg-id 3323.1432762619@sss.pgh.pa.us
Whole thread Raw
In response to Improving GEQO  (boix <boix@uclv.cu>)
Responses Re: Improving GEQO  (boix <boix@uclv.cu>)
List pgsql-hackers
boix <boix@uclv.cu> writes:
> Hello, my partner and me are working with the goal of improve the GEQO's 
> performance, we tried with Ant Colony Optimization, but it does not 
> improve, actually we are trying with a new variant of Genetic Algorithm, 
> specifically Micro-GA. This algorithm finds a better solution than GEQO 
> in less time, however the total query execution time is higher. The 
> fitness is calculated by geqo_eval function. Does anybody know why this 
> happens?

Well, for one thing, you can't just do this:

+                    aux = aux1;

without totally confusing all your subsequent steps.

You'd want to copy the pointed-to data, likely, not the pointer.
        regards, tom lane



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