Re: Improving GEQO

From: boix <boix(at)uclv(dot)cu>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Improving GEQO
Date: 2015-05-28 14:40:32
Message-ID: 556728E0.5020202@uclv.cu
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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(at)uclv(dot)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

Attachment Content-Type Size
microg.patch text/x-patch 13.3 KB

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