A discussion and extension of "A Transparent Schema-Evolution System Based on Object-Oriented View Technology" by Young-Gook Ra and Elke A. Rundensteiner

In the article, Ra and Rundensteiner discuss a system which is the solution to the problem of updating a multi-user database for a particular user. When the user makes an update of his personal view, then there is a possibility that other users of the database cannot run their own applications due to this update. This problem can be solved when a particular user updates his own view first and then integrate this view with the total global schema of the database. This system is called schema evolution using view facilities. In order to make changes to his personal view, the person uses object algebra. Object algebra uses a kind of hierarchical structure with a basic element called class (object), together with methods, attributes and inheritance possibilities. Algorithms which are described in the article are using this object algebra. In the extension of this article I will describe these algorithms along with some complexity-analysis. Furthermore I will make a comparison with PSM and ..