Time and Time Again: Managing Time in Relational Databases, Part 21 – Enforcement Time Options for Temporal RI:
At the conclusion of our previous article, we said that there are two options for enforcing temporal integrity constraints on a database. One is to enforce the constraints at the time of update so as to prevent violations from being persisted in the database. The other is to let violations occur, but to filter them out at retrieval time. This would be done by means of views against which all normal queries would be written.