Re: [WIP] Zipfian distribution in pgbench
Alik Khilazhev <a.khilazhev@postgrespro.ru>
From: Alik Khilazhev <a.khilazhev@postgrespro.ru>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2017-07-17T11:18:46Z
Lists: pgsql-hackers
Attachments
- syntheticdatagen.pdf (application/pdf)
- (unnamed) (text/plain)
> On 17 Jul 2017, at 13:51, Fabien COELHO <coelho@cri.ensmp.fr> wrote: > > > Is this bias expected from the drawing method, say because it is approximated and the approximation is weak at some points, or is there an issue with its implementation, says some shift which gets smoothed down for higher indexes? > I have checked paper where such implementation was proposed and there theta allowed only on range between 0 and 1. It seems like it is not guaranteed that it should work well when theta is more than 1. I am attaching paper, see page 23.
Commits
-
Add approximated Zipfian-distributed random generator to pgbench.
- 1fcd0adeb38d 11.0 landed