Abstract: "It has been shown that the database schemata often experience considerable changes during the development and initial use phases of database systems for advanced applications, such as automated manufacturing and computer-aided design. An automated schema evolution system can significantly reduce the amount of work and potential errors related to schema changes. Although schema evolution for non-real-time databases was the subject of some previous research, its impact on real- time database systems remains unexplored. Since these advanced applications typically utilize object-oriented models to handle complex data types and there exists no agreed-upon real-time object model that can be used as foundation to define a schema evolution framework, we first design a conceptual real-time object-oriented data model, called ROMPP. It captures the key characteristics of real-time applications, namely, timing constraints and performance polymorphism. It uses specialization dimensions to model timing specifications and letter class hierarchies to capture performance polymorphism. We then re-evaluate previous (non-real- time) schema evolution support in the context of real-time databases, which results in several modifications to the semantics of schema changes and to the needs of schema change resolution rules and schema invariants. Furthermore, we expand the schema change framework with new constructs -- including new schema change operators, new resolution rules, and new invariants -- for handling additional features of the real-time object model."

The Ninth International Workshop on Foundations of Models and Languages for Data and Objects (FoMLaDO) took place in Dagstuhl Germany, Sept- ber 18{21, 2000. The topic of this workshop was Database schema Evolution and Meta-Modeling; this FoMLaDO Workshop was hence assigned the acronym DEMM 2000. These post-proceedings contain the revised versions of the accepted papers of the DEMM 2000 workshop. Twelve regular papers were accepted for inclusion in the proceedings. The papers address the following issues: { Consistency of evolving concurrent information systems { Adaptive speci cations of technical information systems { Change propagation in schema evolution of object-based systems { Evolving software of a schema evolution system { Logical characterization of schema evolution { Con?ict management in integrated databases { Evolving relation schemas { Conceptual descriptions of adaptive information systems { OQL-extensions for metadata access { Metamodeling of schema evolution { Metrics for conceptual schema evolution { Incremental datawarehouse construction In addition to the regular papers, there is an invited paper by Can Turk ̈ er on schema evolution in SQL99 and (object-)relational databases. Acknowledgements: We wish to thank the program committee members for their work on reviewing the submitted papers. We also wish to thank all a- hors for submitting papers to this workshop. Moreover, all participants of the workshop are thanked for contributing to lively discussions. Thanks also to Elke Rundensteiner, who delivered an invited talk on the SERF-project concerning ?exible database transformations.

Recently, a set of new software development techniques – termed Aspect-Oriented Software Development (AOSD) – has become available that aims to support modularisation of systemic properties (also referred to as crosscutting-concerns) and their subsequent composition with other parts of the system. Rashid focuses on the use of Aspect-Oriented Programming (AOP) techniques to modularise otherwise broadly scoped features in database systems like the transaction or the versioning model to improve their customisability, extensibility, and maintainability. His aim is to show how the use of AOP can transform the way we develop, use and maintain database systems. He also discusses how database systems can support AOP by providing means for storage and retrieval of aspects. Aspect-Oriented Databases Systems shows the possible synergy between AOSD and database systems and is of particular interest for researchers, graduate students and software developers in database systems and applications.