Kevin Grittner, 15.03.2013 14:36:
> <soapbox-rant>
> I occasionally hear someone maintaining that having a meaningless
> sequential ID column as the primary key of each table is required
> by the relational model. At those moments I swear I can actually
> hear E.F. Codd turning in his grave. It was a requirement of old
> pre-relational databases from the 60's and 70's, and some equally
> primitive ORMs still like to have one, but a big point of
> relational databases is that you don't need to navigate artificial
> linkages between tables -- the relationship can generally be
> determined by the fact that they contain common data elements. If
> these are natural, meaningful values which are visible to the user
> it often allows complex queries to be much better optimized, since
> they aren't forced through a single navigational linkage.
> </soapbox-rant>
You might be interested in a discussion regarding this topic on comp.databases.theory:
https://groups.google.com/forum/?fromgroups=#!topic/comp.databases.theory/mqZZw3ojnjA
