6 research outputs found
Pattern Reification as the Basis for Description-Driven Systems
One of the main factors driving object-oriented software development for
information systems is the requirement for systems to be tolerant to change. To
address this issue in designing systems, this paper proposes a pattern-based,
object-oriented, description-driven system (DDS) architecture as an extension
to the standard UML four-layer meta-model. A DDS architecture is proposed in
which aspects of both static and dynamic systems behavior can be captured via
descriptive models and meta-models. The proposed architecture embodies four
main elements - firstly, the adoption of a multi-layered meta-modeling
architecture and reflective meta-level architecture, secondly the
identification of four data modeling relationships that can be made explicit
such that they can be modified dynamically, thirdly the identification of five
design patterns which have emerged from practice and have proved essential in
providing reusable building blocks for data management, and fourthly the
encoding of the structural properties of the five design patterns by means of
one fundamental pattern, the Graph pattern. A practical example of this
philosophy, the CRISTAL project, is used to demonstrate the use of
description-driven data objects to handle system evolution.Comment: 20 pages, 10 figure
The Reification of Patterns in the Design of Description-Driven Systems
To address the issues of reusability and evolvability in designing self-
describing systems, this paper proposes a pattern-based, object-oriented,
description-driven system architecture. The proposed architecture embodies four
pillars - first, the adoption of a multi-layered meta-modeling architecture and
reflective meta-level architecture, second, the identification of four data
modeling relationships that must be made explicit such that they can be
examined and modified dynamically, third, the identification of five design
patterns which have emerged from practice and have proved essential in
providing reusable building blocks for data management, and fourth, the
encoding of the structural properties of the five design patterns by means of
one pattern, the Graph pattern. The CRISTAL research project served as the
basis onto which the pattern-based meta-object approach has been applied. The
proposed architecture allows the realization of reusability and adaptability,
and is fundamental in the specification of self-describing data management
components.Comment: 10 pages 11 figure
Object Serialization and Deserialization Using XML
Interoperability of potentially heterogeneous databases has been an ongoing
research issue for a number of years in the database community. With the trend
towards globalization of data location and data access and the consequent
requirement for the coexistence of new data stores with legacy systems, the
cooperation and data interchange between data repositories has become
increasingly important. The emergence of the eXtensible Markup Language (XML)
as a database independent representation for data offers a suitable mechanism
for transporting data between repositories. This paper describes a research
activity within a group at CERN (called CMS) towards identifying and
implementing database serialization and deserialization methods that can be
used to replicate or migrate objects across the network between CERN and
worldwide centres using XML to serialize the contents of multiple objects
resident in object-oriented databases.Comment: 14 pages 7 figure