I could of course use rand(), the trouble with this approach is you end up with junk-looking data that is difficult to differentiate from real junk produced by buggy code.
For example, I would like my dummy suscribers' adresses to look like real-world adresses.
Furthermore I don't know how to query for a randomly generated value.
There may exist well-known solution to this problem but I'm quite new to the field of database development. So thanks for any clue...