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Filtered index on primary key.
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De
08/10/1999 13:01:54
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00274111
Message ID:
00274336
Vues:
53
>
>A primary key is an internal relational database issue and has nothing to do with how the user refers to the record. E.F. Codd said "Intelligent keys aren't!". He meant that a primary key that carries other meaning within the entity is a bad idea. Why, because if the primary key means somehting to the user then the user will eventually want to change it and that causes maintenance overhead as the child tables are brought into compliance.
>


Jim, I agree with you on this, but you have piqued my interest on exactly how PKs are defined. I guess it's time to go through the boxes in the basement and find my college text that Codd wrote.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer
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