Re: Random not so random
Bruno Wolff III <bruno@wolff.to>
From: Bruno Wolff III <bruno@wolff.to>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Arnau Rebassa <arebassa@hotmail.com>, pgsql-general@postgresql.org
Date: 2004-10-04T15:57:42Z
Lists: pgsql-general
On Mon, Oct 04, 2004 at 10:14:19 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote: > > It occurs to me that you might be seeing predictability as an indirect > result of something else you are doing that somehow tends to synchronize > the backend start times. Are you connecting from a cron script that > would tend to be launched at the same relative instant within a second? > > It might improve matters to make the code do something like > > srandom((unsigned int) (now.tv_sec ^ now.tv_usec)); Using /dev/urandom, where available, might be another option. However, some people may not want their entropy pool getting 4 bytes used up on every connection start up.