Udo W. Lipeck – författare

Database modelling is concerned with the design of reliable and efficient database systems. Three different approaches to modelling can be identified: structure-oriented, process-oriented, and behaviour-oriented. Database literature has traditionally focused on structure-oriented approaches, but it is now widely recognised that problems can be solved more effectively by integrating all three. As a result, modelling database dynamics is now considered to be as important as modelling static database structures. This volume contains selected papers from the Fourth International Workshop on Foundations of Models and Languages for Data and Objects, held in Volkse, Germany, 19-22 October, 1992. This series of international workshops was initiated by the Working Group on Foundations of Information Systems, part of the German Association for Informatics. It provides an international forum for the discussion of current research into database theory and its application to database technology. The theme of this particular workshop was modelling the dynamic behaviour of database systems in formal frameworks. As object-oriented principles are being widely used in current research work, particular emphasis was also given to object dynamics. Among the topics covered in this volume are: specifying the dynamics of complex objects databases; updates in a rule-based language for objects; an order-sorted approach to active objects; non-deterministic aspects of database transformations involving object creation; monitoring temporal permissions using partially evaluated transition graphs; a formalisation of logic databases and integrity constraints; a comparison of approaches for modelling dynamics of databases. Modelling Database Dynamics provides a comprehensive overview of current research into the modelling and use of database dynamics. It will provide invaluable reading for researchers, postgraduate students, and anyone interested in the theoretical foundations of computer science.

Database modelling is concerned with the design of reliable and efficient database systems. Three different approaches to modelling can be identified: structure-oriented, process-oriented, and behaviour-oriented. Database literature has traditionally focused on structure-oriented approaches, but it is now widely recognised that problems can be solved more effectively by integrating all three. As a result, modelling database dynamics is now considered to be as important as modelling static database structures. This volume contains selected papers from the Fourth International Workshop on Foundations of Models and Languages for Data and Objects, held in Volkse, Germany, 19-22 October, 1992. This series of international workshops was initiated by the Working Group on Foundations of Information Systems, part of the German Association for Informatics. It provides an international forum for the discussion of current research into database theory and its application to database technology. The theme of this particular workshop was modelling the dynamic behaviour of database systems in formal frameworks. As object-oriented principles are being widely used in current research work, particular emphasis was also given to object dynamics. Among the topics covered in this volume are: specifying the dynamics of complex objects databases; updates in a rule-based language for objects; an order-sorted approach to active objects; non-deterministic aspects of database transformations involving object creation; monitoring temporal permissions using partially evaluated transition graphs; a formalisation of logic databases and integrity constraints; a comparison of approaches for modelling dynamics of databases. Modelling Database Dynamics provides a comprehensive overview of current research into the modelling and use of database dynamics. It will provide invaluable reading for researchers, postgraduate students, and anyone interested in the theoretical foundations of computer science.

Aufgabe des Datenbank-Entwurfs ist es, nicht nur die statische Struktur, sondern auch das dynamische Verhalten eines Datenbanksystems zu spezifizieren. Um festzulegen, welche Folgen von Datenbankzuständen zulässig sind, gibt man dynamische Integritätsbedingungen an. Komplementär dazu bestimmen Transaktionen als Grundbausteine von Anwendungsprogrammen die ausführbaren Zustandsfolgen. Diese Monographie stellt zwei Ansätze zur Überwachung der dynamischen Integrität von Datenbanken vor. Es werden theoretische und algorithmische Grundlagen sowie die beim Datenbank-Entwurf erforderlichen Vorbereitungen behandelt. Die Verfahren werden anhand eines durchlaufenden Standardbeispiels demonstriert. Spezifiziert werden Integritätsbedingungen durch Formeln einer temporalen Logik und Transaktionen durch Vor-/Nachbedingungen; die Semantik dieser Kalküle wird im Buch eingeführt. Aus temporalen Formeln lassen sich Transitionsgraphen konstruieren, deren Pfade den zulässigen Zustandsfolgen entsprechen. Daher dienen die Graphen einerseits als Ablaufsteuerung eines universellen Monitors, der die Analyse von Zustandsfolgen auf zustandslokale Prüfungen zurückführt. Andererseits kann man anhand der Graphen Integritätsbedingungen systematisch in Vor-/Nachbedingungen von Transaktionen transformieren, so daß jede ausführbare Zustandsfolge zulässig wird. Das letztere Vorgehen bereitet eine effiziente transaktionsangepaßte Überwachung vor und führt zu einer Spezifikation von Datenbankverhalten durch schrittweise Verfeinerung.