Re: Optimizing Node Files Support - Mailing list pgsql-hackers

From John Naylor
Subject Re: Optimizing Node Files Support
Date
Msg-id CAFBsxsE+cuaUGTJfDGLK8tx+a5DKyk-9+PA7qnb2OgUBYORZtQ@mail.gmail.com
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In response to Optimizing Node Files Support  (Ranier Vilela <ranier.vf@gmail.com>)
Responses Re: Optimizing Node Files Support  (Ranier Vilela <ranier.vf@gmail.com>)
List pgsql-hackers

On Thu, Dec 1, 2022 at 8:02 PM Ranier Vilela <ranier.vf@gmail.com> wrote:
>
> Hi,
>
> I believe that has room for improving generation node files.
>
> The patch attached reduced the size of generated files by 27 kbytes.
> From 891 kbytes to 864 kbytes.
>
> About the patch:
> 1. Avoid useless attribution when from->field is NULL, once that
> the new node is palloc0.
>
> 2. Avoid useless declaration variable Size, when it is unnecessary.

Not useless -- it prevents a multiple evaluation hazard, which this patch introduces.

> 3. Optimize comparison functions like memcmp and strcmp, using
>  a short-cut comparison of the first element.

Not sure if the juice is worth the squeeze. Profiling would tell.

> 4. Switch several copy attributions like COPY_SCALAR_FIELD or COPY_LOCATION_FIELD
> by one memcpy call.

My first thought is, it would cause code churn.

> 5. Avoid useless attribution, ignoring the result of pg_strtok when it is unnecessary.

Looks worse.

--
John Naylor
EDB: http://www.enterprisedb.com

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