Re: Elocution - Mailing list pgsql-advocacy

From Justin Clift
Subject Re: Elocution
Date
Msg-id 3DF59006.8030302@postgresql.org
Whole thread Raw
In response to Re: Elocution  (Dennis Björklund <db@zigo.dhs.org>)
Responses Re: Elocution  (Joe Conway <mail@joeconway.com>)
List pgsql-advocacy
Joe Conway wrote:
> Justin Clift wrote:
>
>> The OSDB software (another Open Source database testing tool) has
>> added the
>> ability to generate large datasets in recent CVS, so that's another
>> avenue
>> for testing with as well.
>
>
> Just one note on this. If we ever get serious about using OSDB to
> compare Postgres with MySQL, it needs some hacking in order to get a
> fair comparison.
>
> The problem as I recall is that the two longest running tests (and
> therefore the ones with the largest impact on the overall result) are
> designed to fetch rows one-at-a-time. The Postgres version does this by
> using a CURSOR and FETCH 1, while the MySQL version has to fake it using
> the MySQL client library to buffer the rows. In other words, the MySQL
> version of this benchmark is uses a local library and cache, instead of
> making a round trip to the server for each row (something like 10000
> times)!
>
> To make the comparison fair, the Postgres version should FETCH the
> entire result once using libpq, and then dole out the rows one-at-a-time
> similar to the MySQL version.

Ok, that makes sense.  Andy (the author of OSDB) seems to be happy to
accept suggestions like this.  He has knocked back suggested
improvements (and patches) that he feels change the way OSDB runs in
relation to the AS3AP spec, but this sounds like it's would be far more
efficient and also not change the principle of things.

Would it be cool to forward this suggestion to Andy?

:-)

Regards and best wishes,

Justin Clift


> Joe
>
>


--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
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