A time framework for temporal databases

摘要

There are two different strategies for incorporating a temporal dimension into the relational models in the literature. One is the first-normal-form (1NF) model; and the other is the non-first-normal-form (N1NF) model. Both of them are required to support an ability of handling data with temporal element (or temporal set, or gap-interval). In order to support these temporal operations for temporal databases, some basic concepts and a calculus form between temporal elements are established.