Asynchronous data retrieval from an object-oriented database

We present an object-oriented semantic database model which, similar to other object-oriented systems, combines the virtues of four concepts: the functional data model, a property inheritance hierarchy, abstract data types and message-driven computation. The main emphasis is on the last of these four concepts. We describe generic procedures that permit queries to be processed in a purely message-driven manner. A database is represented as a network of nodes and directed arcs, in which each node is a logical processing element, capable of communicating with other nodes by exchanging messages. This eliminates the need for shared memory and for centralized control during query processing. Hence, the model is suitable for implementation on a multiprocessor computer architecture, consisting of large numbers of loosely coupled processing elements

A general framework for positioning, evaluating and selecting the new generation of development tools.

This paper focuses on the evaluation and positioning of a new generation of development tools containing subtools (report generators, browsers, debuggers, GUI-builders, ...) and programming languages that are designed to work together and have a common graphical user interface and are therefore called environments. Several trends in IT have led to a pluriform range of developments tools that can be classified in numerous categories. Examples are: object-oriented tools, GUI-tools, upper- and lower CASE-tools, client/server tools and 4GL environments. This classification does not sufficiently cover the tools subject in this paper for the simple reason that only one criterion is used to distinguish them. Modern visual development environments often fit in several categories because to a certain extent, several criteria can be applied to evaluate them. In this study, we will offer a broad classification scheme with which tools can be positioned and which can be refined through further research.

Compensation methods to support cooperative applications: A case study in automated verification of schema requirements for an advanced transaction model

Compensation plays an important role in advanced transaction models, cooperative work and workflow systems. A schema designer is typically required to supply for each transaction another transaction to semantically undo the effects of . Little attention has been paid to the verification of the desirable properties of such operations, however. This paper demonstrates the use of a higher-order logic theorem prover for verifying that compensating transactions return a database to its original state. It is shown how an OODB schema is translated to the language of the theorem prover so that proofs can be performed on the compensating transactions

Encapsulation and information hiding as the keys to maintainable and reusable hypermedia applications.

This paper presents a solution to the maintenance problem in hypermedia by applying object-oriented techniques to both the hypermedia data model and the hypermedia system's actual implementation. First, the primary concepts of the 'MESH' (Maintainable, End user friendly, Structured Hypermedia) approach are discussed briefly. These consist of a conceptual data model, a navigation paradigm and an implementation framework. Thereafter, it is shown how the object-oriented concepts of encapsulation and information hiding result in a hypermedia system consisting of self-contained, independently coded nodes. Intra node maintenance is separated entirely from inter node maintenance: the hyperbase's link structure can be updated without affecting node content, whereas an individual node's multimedia content can be reorganized without necessitating updates to links or link anchors.Applications; Information; Data; Model; Structure;

Comparison of RDBMS, OODBMS and ORDBMS

The presentation of the similarities and differences between relational modeling of data and the object oriented modeling of data is of great importance both for data base designers and for users. By being well acquainted with the relational model and by noting the similarities and differences between the two approaches to data modeling, designers will be able to turn into account and to make use of the already acquired experience as an important basis for understanding and learning the methodology of designing object oriented databases. At the time if designers know the similarities and differences between these two approaches they have the possibility to convert a relational model into an object oriented model and inverselyRDBMS, OODBMS and ORDBMS comparatively

Facets and Typed Relations as Tools for Reasoning Processes in Information Retrieval

Faceted arrangement of entities and typed relations for representing different associations between the entities are established tools in knowledge representation. In this paper, a proposal is being discussed combining both tools to draw inferences along relational paths. This approach may yield new benefit for information retrieval processes, especially when modeled for heterogeneous environments in the Semantic Web. Faceted arrangement can be used as a se-lection tool for the semantic knowledge modeled within the knowledge repre-sentation. Typed relations between the entities of different facets can be used as restrictions for selecting them across the facets