Questions about data that is organized into types and subtypes.
Subtypes, often called subclasses, come up often in the course of processing data. Subtypes also come up often when managing data that is to be processed or to be retained in a database.
Object oriented processing environments accommodate subtypes fairly well. The inheritance mechanism is central to object oriented systems, and provides a natural way of managing subtypes. Relational systems are less well adapted to managing subtypes. Programmers, DBAs, and database builders often have to implement the infrastructure themselves.
Many of the people who ask about subtypes are experienced programmers who are proficient in OOP. They are often new to the kind of data management that DBAs do.
This tag is for questions about how to handle subtypes in a database environment. The questions might relate to subtype data definition, to updating subtype data, or to constructing queries involving subtype data.