Re: [PERFORM] pgbench to the MAXINT
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Smith <greg@2ndquadrant.com>
Cc: Stephen Frost <sfrost@snowman.net>, Euler Taveira de Oliveira <euler@timbira.com>, Pgsql Hackers <pgsql-hackers@postgresql.org>
Date: 2011-02-11T03:18:38Z
Lists: pgsql-hackers, pgsql-performance
Greg Smith <greg@2ndquadrant.com> writes: > Poking around a bit more, I just discovered another possible approach is > to use erand48 instead of rand in pgbench, which is either provided by > the OS or emulated in src/port/erand48.c That's way more resolution > than needed here, given that 2^48 pgbench accounts would be a scale of > 2.8M, which makes for a database of about 42 petabytes. I think that might be a good idea --- it'd reduce the cross-platform variability of the results quite a bit, I suspect. random() is not to be trusted everywhere, but I think erand48 is pretty much the same wherever it exists at all (and src/port/ provides it elsewhere). regards, tom lane