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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 *** Sent via Developersdex http://www.developersdex.com *** Don't just participate in USENET...get rewarded for it!
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