
16.1 Overview
When the ancient Greek philosopher Heraclitus said that “everything is in a state of
flux,” he was not thinking of data models, but he might as well have been. No matter
how good the initial data model and the resulting physical schema, it is almost
inevitable you will need to make at least some changes during the life of the database.
Good initial modeling will minimize the overall need for changes, and lessen the
severity of those changes, but you should still expect to make changes along the way.
Changes to data structures are disruptive, and can have a far reaching impact on
existing applications, and the members of a software development ...