Re: random() in multi-threaded pgbench

I wrote:
> Takahiro Itagaki <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp> writes:
>> http://www.kernel.org/doc/man-pages/online/pages/man3/random_r.3.html

> It only says that you need those if you want an *independent* random
> sequence for each thread. pgbench never had that before and I doubt
> we need it now. In any case, the same page also says these are a
> glibc-ism not a standard API, so we can't really rely on them.

... although if anyone was sufficiently excited about this, we could
make use of erand48() without adding any new platform dependency,
since GEQO is already relying on that. I think there's not much
point though. We'd just be moving the nearest point of failure to
the seeding algorithm --- careless seeding could still result in
duplicate sequences for different threads.

regards, tom lane