Re: Improving GEQO - Mailing list pgsql-hackers

From boix
Subject Re: Improving GEQO
Date
Msg-id 556728E0.5020202@uclv.cu
Whole thread Raw
In response to Re: Improving GEQO  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
We follow your advice, our goal is improve the quality of the solution and we made it, however the total query execution time is higher.
Regards.

On 05/27/2015 04:36 PM, Tom Lane wrote:
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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