Re: Random not so random

"D. Stimits" <stimits@comcast.net> writes:
> Tom Lane wrote:
>> Hmm.  postmaster.c does this during startup of each backend process:
>> 
>> gettimeofday(&now, &tz);
>> srandom((unsigned int) now.tv_usec);

> If it uses the same seed from the connection, then all randoms within a 
> connect that has not reconnected will use the same seed. Which means the 
> same sequence will be generated each time, which is why it is 
> pseudo-random and not random. For it to be random not just the first 
> call of a new connection, but among all calls of new connection, it 
> would have to seed it based on time at the moment of query and not at 
> the moment of connect. A pseudo-random generator using the same seed 
> will generate the same sequence.

Did you read what I said?  Or experiment?

			regards, tom lane