Temporal Databases

There are many applications that need temporal aspects in many domains.

Usually they are used for:

  • versioning
  • specifying some periods of time
  • etc


Time and Facts

Valid time of a fact:

  • when the fact is (was, will be) true in the modeled reality
  • independent of the transaction time
  • can be past, present, future
  • (link to Slowly Changing Dimensions)?

Transaction time of a fact:

  • when the fact was recorded in a database


Temporal ER Diagrams

Conceptual Modeling of Temporal aspects:


Querying

How to query a temporal database?


Sources