Should dates for a temporal database stored in one or 2 tables ? If one doesn't this violate normalisation ?
PERSON1 DATE11 DATE21 INFO11 INFO21 DEPRECATED
PERSON2 DATE21 DATE22 INFO21 INFO22 CURRENT
PERSON1 DATE31 DATE32 INFO31 INFO32 CURRENT
DATE1 and DATE2 Columns indicate that INFO1 and INFO2 are true for the period between DATE1 and DATE2. If DATE < TODAY, the facts are deprecated and shouldn't show any more in the user interface but they shouldn't be deleted for historical purpose. For example INFO11 and INFO21 are now deprecated.
Should I split this table ? Should I store the state (deprecated or current) in the table ?
To clarify the question further more, Deprecated is the term used by the Business, if you prefer "not current", the problem is not semantic, it's not about sql queries either, I just want to know which design violates or best suits Normalisation rules (I know normalisation is not always the way to go, that is not my question either).