> From: Richard Reina <gatorre...@gmail.com> > > I want to create a US geography database. So far I have categories such as > state nick names (some states have more than one), state mottos (text 25 to > 150 characters), state name origins (100-300 characters), state "trivial > facts", entry into union. My question is; would it be better to keep at > least some of this information in separate tables...
To me, the key question is cardinality. You gave a big clue with "some states have more than one." This "cardinality rule" clearly indicates you need a separate table for nick names. I'd look carefully at cardinality, and any field in which you can say, "some states may have more than one," put it in a separate table. (One exception to cardinality-driven table design would be if a field is a clearly defined, relatively unchanging set of constants. The classic example is when different states in a process need to be recorded -- "membership" might include the set "applied", "paid", "accepted", "withdrawn". You could have multiple states in a SET field, which would be much less cumbersome than having a fifth-normal-form join table.) ---------------- A low-energy policy allows for a wide choice of lifestyles and cultures. If, on the other hand, a society opts for high energy consumption, its social relations must be dictated by technocracy and will be equally degrading whether labeled capitalist or socialist. -- Ivan Illich :::: Jan Steinman, EcoReality Co-op :::: -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
