Hi,

I need a Ref. num CHAR(16) out of which the first 3 Chars I am using to specify the type of the Process. The remaining I am using to have a Random number.

Somebody please specify what is the best logic I can follow as my system is going to face a big load. I want my Random number to be as best as possible.


Thanks in Advance.

Balisetty.

DB2 provides a function RAND() which generates a random number.
To convert that number into a char(13) string, you might use:

SUBSTR(CAST(RAND() AS CHAR(15) ),3,13)

Just try it:
SELECT SUBSTR(CAST(RAND() AS CHAR(15) ),3,13)
FROM SYSIBM.SYSDUMMY1

Thanks a lot.

Is there any alternate / better way of doing the same ?



Rgds,
Balisetty

What about using the microsecond part of the current time ???

Sathyaram

Do the random numbers have to all be different? Do they have to be unique?

A random number sequence should guarantee independence of its elements. Unicity is not a criterion: by coincidence two numbers might be identical, and the probability of this to occur should be exactly equal to 1/n, where n is the number of different random numbers that can be generated (in case of a uniformly distributed random number, which is most often what people want).
"Independence" means that e.g. the value of the second number is not influenced by the first one, i.e., that it has probability 1/n of being any of the n possibly outcomes, just like the first one had.