Horton

Re: [WIP] Zipfian distribution in pgbench

Alik Khilazhev <a.khilazhev@postgrespro.ru>

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From: Alik Khilazhev <a.khilazhev@postgrespro.ru>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2017-07-17T10:34:15Z
Lists: pgsql-hackers 
Hello Fabien,

> On 14 Jul 2017, at 17:51, Fabien COELHO <coelho@cri.ensmp.fr> wrote:
> 
> Ok, so you did not get the large bias for i=3. Strange.

I got large bias for i=3 and theta > 1 even with a million outcomes, but for theta < 1 (I have tested on theta = 0.1 and 0.3) it showed quite good results.


I am attaching patch v3. Among other things I fixed small typo in description of random_exponential function in pgbench.sgml file.


—
Thanks and Regards,
Alik Khilazhev
Postgres Professional:
http://www.postgrespro.com <http://www.postgrespro.com/>
The Russian Postgres Company

Commits

  1. Add approximated Zipfian-distributed random generator to pgbench.