Bernhard Mitschang

Processing and transaction concepts for cooperation of engineering workstations and a database server

Abstract A DBMS kernel architecture is proposed for improved DB support of engineering applications running on a cluster of workstations. Using such an approach, part of the DBMS code—an application-specific layer—is allocated close to the corresponding application on a workstation while the kernel code is executed on a central server. Emperical performance results from DB-based engineering applications are reported to justify the chosen DBMS architecture. The paper focuses on design issues of the application layer including server coupling, processing model and application interface. Moreover, a transaction model for long-term database work in a coupled workstation-server environment is investigated in detail.

Grand tour of concepts for object-orientation from a database point of view

Abstract Over the last few years, object-orientation has gained more and more importance within several disciplines of computer science (e.g. programming languages, knowledge engineering, and database systems). Numerous papers have defined one or another of its underlying concepts (sometimes in quite different ways), and some systems have been developed following those heterogeneous definitions. Nevertheless, papers investigating the dependencies and degrees of freedom of these concepts are rarely found. For this reason, the goal of this paper is not to add yet another definition of object-oriented concepts, but to identify existing relationships among these basic concepts that allow one to cover and classify various conceivable combinations of these conceptual building blocks. Dependencies, orthogonalities, and relations among concepts like object identity, encapsulation, classification, generalization, inheritance, etc. are revealed, showing numerous ways to compose different shades of object-orientation. This leads to alternatives encountered when constructing object-oriented systems, which are illustrated by classifying some well-known systems and prototypes from different areas. However, it is not our purpose to analyze the relative importance of these concepts. Instead, we investigate the concepts from a neutral point of view, presenting (but not evaluating) several degrees of object-orientation.

SQL/XNF-Processing composite objects as abstractions over relational data

An extension to SQL, called the SQL extended normal form (XNF), is discussed. It enhances relational technology by a composite object facility, which comprises not only extraction of composite objects from existing databases but also efficient navigation and manipulation facilities provided by an appropriate application programming interface. The language itself allows sharing of the database among normal form SQL applications and composite object applications. It provides proper subsetting of the database and subsequent structuring, exploiting subobject sharing and recursion, all based on its powerful composite object constructor concept, which is closed under the language operations. XNF is integrated into the relational framework, thus benefiting from the available technology such as relational engine and query optimization.<<ETX>>

KRISYS: KBMS support for better CAD systems

The authors propose a knowledge-base management system based on the integration of database and artificial intelligence technology that provides adequate capabilities for the construction of advanced CAD systems. The approach is evaluated in view of other systems and its suitability is demonstrated by means of some examples from the area of architectural design. Throughout the authors refine their views of advanced CAD and define some inherent characteristics of better CAD.<<ETX>>

Integrated document management system

Abstract not available.

An approach to integrated office document processing and management

We propose an approach towards an integrated document processing and management system that has the intention to capture essentially freely structured documents, like those typically used in the office domain. The document analysis system ANASTASIL is capable to reveal the structure as well as the contents of complex paper documents. Moreover, it facilitates the handling of the containing information. Analyzed documents are stored in the management system KRISYS that is connected to several different subsequent services. The described system can be considered as an ideal extension of the human clerk, making his tasks in information processing easier. The symbolic representation of the analysis results allow an easy transformation in a given international standard, e.g., ODA/ODIF or SGML, and to interchange it via global network.

Flexible Entwurfsdatenverwaltung für CAD-Frameworks: Konzept, Realisierung und Bewertung

Eine der Hauptzielrichtungen von CAD-Frameworks ist die Integration von einzelnen, eigenstandigen CAD-Werkzeugen mittels einer zentralen Datenverwaltung. Wesentliche Aufgaben hierbei sind die Verwaltung aller entwurfsrelevanten Daten sowie die effiziente Bereitstellung werkzeugrelevanter Daten fur den werkzeugspezifischen Entwurfsschritt. Hierzu sind die vom jeweiligen Werkzeug zu bearbeitenden Entwurfsdaten bzw. Entwurfsobjekte zu selektieren und in der jeweils benotigten Form bereitzustellen. Nach Beendigung des Entwufsschrittes sind die geanderten Daten in den aktuellen Datenbestand zu integrieren. Um diese schwierige Aufgabe meistern zu konnen, ist es notig, die vorherrschenden Objekt- und Entwurfsstrukturen entsprechend zu berucksichtigen.

Information Structures and Database Support for Solid Modeling

The question we are going to investigate is how to map solid representations to DB structures and how to process this information efficiently. Starting from analytical representations based on analytical methods we discuss the use of constructive solid geometry and boundary representation models with various refinements. Furthermore, additional submodels (organizational, technological, physical) are considered in order to obtain an overall product model. This model representing all important aspects of a complex design object may serve to derive special object representations needed by existing engineering tools or by mathematical methods (e.g. finite elements).

DB-Schnittstellen für arbeitsplatzorientierte Ingenieuranwendungen

Die Schnittstellen gegenwartig verfugbarer Datenbanksysteme erweisen sich als ungeeignet fur den Bereich der lngenieuranwendungen. Dies gilt im besonderen, da bei Ingenieuranwendungen eine deutliche Arbeitsplatzorientierung vorherrscht und sie damit haufig auf einer speziellen Mehrrechnerarchitektur aufbauen. Ausgehend von einem Schichtenmodell fur sog. Non-Standard-Datenbanksysteme (NDBS) schlagen wir daher eine spezielle Systemarchitektur mit einer entsprechend ausgelegten Datenmodell- und Anwendungsmodellschnittstelle fur arbeitsplatzorientierte Ingenieuranwendungen vor.

Ein Ansatz zu graphischen Datenbanken und deren Verwendung in CAD-Systemen

Die zentrale Aufgabe eines CAD-Systems ist die adaquate Unterstutzung des Konstruktionsvorganges. Dazu mussen die Entwurfsobjekte sowohl graphisch reprasentiert als auch in einer sog. rechnerinternen Darstellung verwaltet werden. Heutzutage stehen fur diese Aufgaben GKS-orientierte Graphiksysteme sowie Datenbanksysteme mit hierarchischer, netzwerkartiger bzw. relationaler Schnittstelle zur Verfugung. Am Beispiel des KUNICAD-Systems (ein datenbankbasierter 3D-Bauteilmodellierer) werden die Schnittstellen zwischen Graphik-, Anwendungs- und Datenhaltungskomponente aufgezeigt und analysiert. Dabei wird die Wichtigkeit der Kopplung von Graphik- und Datenhaltungskomponente erkannt. Als unmittelbare Konsequenz daraus wird die Integration von Graphik- und DB-System zu einem Gesamtsystem, dem Graphischen Datenbanksystem, vorgeschlagen sowie dessen Architekturmerkmale und charakteristischen Eigenschaften vorgestellt.