And a real world example of a table without a natural key.

Call data delivered by a telecom switch

It gave us calling no, called no, start of call, end of call and a load
of other inconsequential data.

Depending on the switch of the company calling it presented the exchange
number not the extention so could validly get identical records so added
an identity.

Ok - so the daata presented wasn't good and we eventually got it changed
to include a sequence no so that we had a natural key (together with the
file createion date/time) but for a long time there was no choice.

Nigel Rivett
www.nigelrivett.net

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