PEMBUATAN APLIKASI UNTUK MENDESAIN BASIS DATA BERDASARKAN SEMANTIC OBJECT MODEL

Penelitian yang dilakukan bertujuan untuk membuat aplikasi yang dapat digunakan untuk mendesain model data dengan pendekatan Semantic Object Model (SOM). Aplikasi tersebut juga dilengkapi dengan fasilitas untuk mentransformasikan SOM ke dalam Basis Data Oracle. Pembuatan aplikasi mengikuti Metode Software Developement Life cycle (SDLC). Berdasarkan hasil pengujian, Aplikasi SOM dapat digunakan untuk mendesain Model Data SOM dan mentransformasikan model data tersebut ke dalam basis data Oracl

DIVERSITY WITH COOPERATION IN DATABASE SCHEMATA: SEMANTIC RELATIVISM

Diversity is an asset, as long as it allows cooperation. In the case of information systems and databases, the data model used is a help or a hindrance for this cooperation of diverse views; this is characterized by the semantic relativism of the model. We first analyze diversity within an information system, where cooperation is made possible by the use of external schemata; semantic relativism of the model of the database schema is the key f,ictor. Then we discuss diversity between different information systenis, where they cooperate through interoperability, by schema integration into federated schemata; semantic relativism of the canonical data model is shown to be determinant

A COMPARISON OF THE DATA AGGREGATION APPROACH WITH THE LOGICAL RELATIONAL DESIGN METHODOLOGY

A laboratory study comparing relational representations developed using the Data Aggregation approach with the Logical Relational Design Methodology (LRDM) was conducted to investigate whether non-expert users could better comprehend and apply either methodology. While no significant differences between user performance were noted, the study did find that subjects following the LRDM produced quality Entity-Relationship (ER) representations, but there was a marked deterioration of the translation to the relational form. The Data Aggregation solutions were generally poor in quality. The study concludes that while non-expert designers can produce acceptable data abstractions using a conceptual modeling methodology (e.g., ER diagrams), problems may arise during conversion to normalized relations (e.g., relational representations)

HOOD : a Higher-Order Object-Oriented Database model and its implementation

Bibliography: pages 133-140.There is no accepted standard for the object-oriented database paradigm at present, which has led to different definitions of features and conformance requirements. HOOD is a Higher-Order Object-Oriented Database system which defines a meta-data model for specifying the requirements of an Object-Oriented Database, which provides uniformity and extensibility. From this specification and by making use of a comprehensive structure system, an exemplar or implementation model is defined. Among the constructs provided by the model are types, instances, objects, values, methods, base types, generic types and metatypes. The mechanisms of instantiation and subtyping allow for relationships between these constructs. Extensibility is provided in the model for types, base types, structures and methods. Uniformity is achieved by defining all constructs as instances and through the use of messages for all operations. There is only one form of object construct which provides persistence and identities. The complex values and extensibility of the model allow it to adapt in order to model the real world instead of adapting the real world to fit the model. We have implemented a subset of the structures and values defined in the model, provided persistence and identities for object, and included the various constructs mentioned above. The method language allows for the specification of methods, the passing of messages, and the use of complex values. The compiler performs type checking and resolution and generates instructions for an abstract machine which manipulates the database