Re: pgbench - allow to specify scale as a size

From: Alvaro Hernandez <aht(at)ongres(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
Cc: PostgreSQL Developers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: pgbench - allow to specify scale as a size
Date: 2018-02-17 16:55:20
Message-ID: f8572028-4c08-1069-611f-b38367ff5911@ongres.com
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On 17/02/18 11:26, Tom Lane wrote:
> Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> writes:
>> Here is a attempt at extending --scale so that it can be given a size.
> I do not actually find this to be a good idea. It's going to be
> platform-dependent, or not very accurate, or both, and thereby
> contribute to confusion by making results less reproducible.
>
> Plus, what do we do if the backend changes table representation in
> some way that invalidates Kaarel's formula altogether? More confusion
> would be inevitable.

    Why not then insert a "few" rows, measure size, truncate the table,
compute the formula and then insert to the desired user requested size?
(or insert what should be the minimum, scale 1, measure, and extrapolate
what's missing). It doesn't sound too complicated to me, and targeting a
size is something that I believe it's quite good for user.

    Álvaro

--

Alvaro Hernandez

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