Due to the 3D architecture of the database, the use of protocols, the business rules and the time model, RIHAD allows the management of longitudinal information through a simple unit that we call longitudinal datum, in the same way that relational databases manage information through a datum.
This is a structure defined by a set of data associated with the same process executed on the same object, that are collected and recorded over time.
Longitudinal information consists on a set of longitudinal data connected through the objects, the protocols executed or only the data.
These concepts are the basis of a database model that we call longitudinal data model. RIHAD presents an implementation of this model using a relational database manager that distributes the data over the 3D architecture, providing longitudinal knowledge at the level of the metadada of the dictionary of a database manager.
RIHAD includes techniques to ensure efficiency in longitudinal information retrieval although the storage system is not properly longitudinal.