Scott Marcus
marcus at tsstech.com
Fri Jun 11 10:25:33 CDT 2004
<< Well, what *is* distinct about a screw from the same lot? Nothing, I was using the example given. What is distinct about 500 red Mustang convertibles coming off of Ford's assembly line? What is distinct about any part made on an assembly line(in the majority of cases)? Nothing, yet because a serial number is placed on it, someone decides that the serial number is a natural key. It isn't any more natural than an auto-number. In fact, I could rename the auto-number field to serial number and then the logic of that argument says that I now have a natural key. Since when would the name of an attribute define it as being a natural key? Scott Marcus TSS Technologies, Inc. marcus at tsstech.com (513) 772-7000 -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte Foust Sent: Friday, June 11, 2004 11:10 AM To: Access Developers discussion and problem solving Subject: RE: [AccessD] OT: The Great Primary Debate Well, what *is* distinct about a screw from the same lot? This is probably a poor example for this discussion because screws of the same size, etc., are interchangeable. There is no need to identify any particular screw from a batch of duplicate screws, so it has no unique key! Charlotte Foust -----Original Message----- From: Scott Marcus [mailto:marcus at tsstech.com] Sent: Friday, June 11, 2004 5:38 AM To: Access Developers discussion and problem solving Subject: RE: [AccessD] OT: The Great Primary Debate Stuart, It was just an example. I worked for GE Aircraft Engines for 2 years. I wrote systems that tracked those screws/nuts/bolts etc. They want to know everything about anything in an engine. They do not however track below a lot number on those common parts. You could find anything you needed to know about a 'lot' of screws but a particular screw from that lot was no different than any other screw in that lot. Scott Marcus TSS Technologies, Inc. marcus at tsstech.com (513) 772-7000 -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Stuart McLachlan Sent: Friday, June 11, 2004 9:27 AM To: Access Developers discussion and problem solving Subject: RE: [AccessD] OT: The Great Primary Debate On 11 Jun 2004 at 8:28, Scott Marcus wrote: > John, > > If you have a bin full of 20,000 screws (all the same, because that's > what I was saying) you would be an amazing person if I could pick up > anyone of them, show it to you, take it back, put it back in the bin, > mix the bin up, and you could find that same exact screw. > You've obviously never developed any systems for the aircraft industry. You need to track what supplier and manufacture batch any individual screw came from, what aircraft it ended up on and where. You just don't dump 20,000 screws in a bin. :-( -- Lexacorp Ltd http://www.lexacorp.com.pg Information Technology Consultancy, Software Development,System Support. -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com