From: | Vivek Khera <khera(at)kcilink(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Random not so random |
Date: | 2004-10-05 21:28:44 |
Message-ID: | x7brfg6eib.fsf@yertle.int.kciLink.com |
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Lists: | pgsql-general |
>>>>> "DS" == D Stimits <stimits(at)comcast(dot)net> writes:
DS> If it uses the same seed from the connection, then all randoms within
DS> a connect that has not reconnected will use the same seed. Which means
DS> the same sequence will be generated each time, which is why it is
DS> pseudo-random and not random. For it to be random not just the first
DS> call of a new connection, but among all calls of new connection, it
DS> would have to seed it based on time at the moment of query and not at
DS> the moment of connect. A pseudo-random generator using the same seed
DS> will generate the same sequence.
You clearly demonstrate you do not understand the purpose of a seed in
a PRNG, nor how PRNG's in general work. You want to seed it once and
only once per process, not every time you issue a query. And nobody
said to use the same seed every time, either.
--
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Vivek Khera, Ph.D. Khera Communications, Inc.
Internet: khera(at)kciLink(dot)com Rockville, MD +1-301-869-4449 x806
AIM: vivekkhera Y!: vivek_khera http://www.khera.org/~vivek/
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