The multi-lingual database system

In the past, the design and implementation of a database system has followed a rather conventional approach. First, a specific data model for the database system is chosen. Second, a corresponding model-based data language is then specified. The result of this traditional approach to the database-system development is a mono-lingual database system where the user sees and uses the database system with a specific data model and its model-based data language. The conventional practice for the database-system design and implementation mandates that a database system must be restricted tot a single data model and a specific model-based data language. This paper introduces a new and unconventional approach to the design and implementation of a database system, the multi-lingual database system (MLDS). The multi-lingual database system is a single database system that can execute many transactions written respectively in different data languages and support many databases structured correspondingly in various data models. For example, this multi-lingual database system can run DL/I transactions on IMS databases, CODASYL-DML transactions on network database, SQL transactions on relational databases and Daplex transactions on entity-relationship databases, where the system appears to the user like a heterogeneous collection of database systems. Thus, a multi-lingual database system allows the old transactions and existing databases to be migrated to the new environment, the experienced user to continue to utilize certain favorite features of existing data languages and data models, the new user to explore the strong features of the various data languages and data models, the hardware upgrade to be focused on a single system instead of a heterogeneous collection of database systems, and the database application to cover wider types of transactions and different modes of interactionssupported in part by the Foundation Research Program of the Naval Postgraduate School with funds provided by the Chief of Naval Researchhttp://archive.org/details/multilingualdata00demuN0001486WR4E001NAApproved for public release; distribution is unlimited

New Directions In Database-Systems Research and Development

Prepared for: Chief of Naval Research Arlington, VA 22217In this paper, three new directions in database-systems research and development are indicated. One new direction is the emergence of the multilingual database systems where a single database system can execute many transactions written respectively in different data languages and support many databases structured correspondingly in various data models. Thus, a multi-lingual database system allows the old transactions and existing databases to be migrated to the new system, the user to explore the strong features of the various data languages and data models in the same system, the hardware upgrade to be focused on a single system instead of a heterogeneous collection of database systems, and the database application to cover wider types of transactions and interaction in the same environment. One other new direction is the emphasis of the multi-backend database systems where the database system is configured with a number of microprocessor-based processing units and their disk subsystems. These processing units and disk subsystems are called database backends. The unique characteristics of the backends are that the number of the backends is variable, the system software in all of the backends is identical, and the multiplicity of the backends is proportional to the performance and capacity of the system. Thus, for the first time, a multi-backend database system enables the user to relate the amount of hardware used (i.e., the number of the backends) to the degree of performance gain and capacity growth of the system. The third new direction is the possibility of the multi-host database systems where a single database system can communicate with a variable number and heterogeneous collection of mainframes in several different data languages and allow the mainframes to share the common database store and access. This paper attempts to articulate the background, benefits, requirements and architectures of these new types of database system, namely, the multi-lingua the multi-backend, and the multi-host database systems.DoD STARS Program and from the Office of Naval Research.Approved for public release; distribution is unlimited

Database Systems - Present and Future

The database systems have nowadays an increasingly important role in the knowledge-based society, in which computers have penetrated all fields of activity and the Internet tends to develop worldwide. In the current informatics context, the development of the applications with databases is the work of the specialists. Using databases, reach a database from various applications, and also some of related concepts, have become accessible to all categories of IT users. This paper aims to summarize the curricular area regarding the fundamental database systems issues, which are necessary in order to train specialists in economic informatics higher education. The database systems integrate and interfere with several informatics technologies and therefore are more difficult to understand and use. Thus, students should know already a set of minimum, mandatory concepts and their practical implementation: computer systems, programming techniques, programming languages, data structures. The article also presents the actual trends in the evolution of the database systems, in the context of economic informatics.database systems - DBS, database management systems – DBMS, database – DB, programming languages, data models, database design, relational database, object-oriented systems, distributed systems, advanced database systems

View mappings for query languages

The problems of current use of query languages are looked at. One chief drawback is the undesirable requirement for end user familiarity with and knowledge of the underlying database structures, in order to retrieve data effectively. The approach adopted towards resolving this is by means of high-level view support, using unit view structures called perceived records. A prime concern of this thesis then, is the study of perceived record mappings from the database. A set of criteria for categorising and analysing the features of database mappings for end-user views is first developed. In addition, a classification of data structure transformations and data item transformations is also presented. The framework is general and is independent of a specific data model or database management system. Its usefulness is demonstrated by its application to the analysis of view transformations from recursive database structures to high-level, unit view structures. In addition, it serves as a basis for evaluating and comparing the mapping facilities in existing systems. Possible ways of specifying a suitable data model for the perceived record view concept are described. Following on, two general mapping techniques are discussed. This leads to a proposal for a mapping mechanism that supports the flexible derivation of complex perceived record views that can differ considerably from the source structures. The mechanism uses an intermediary canonical transform model. Description of how the transform model mechansim can be used in practical systems to derive perceived record views, is also presented. The feasibility of the ideas proposed are tested out by implementing an interactive software system for defining perceived record views. For this, a mapping definition language for perceived record derivation is first designed. The control system sets up the structures of the mapping definition language and prompts the End-User-Administrator to define and specify the mappings for a perceived record. Appraisals of both the proposed mapping mechanism and implementation are discussed. Examples of use of the interface system are included. The limitations of the implementation are pinpointed with suggestions for further improvements. Practical applications of the work and evaluation of the approach in the light of other existing approaches, are also discussed

Heuristic Optimization of Physical Data Bases: Using a Generic and Abstract Design Model

Designing efficient physical data bases is a complex activity, involving the consideration of a large number of factors. Mathematical programming-based optimization models for physical design make many simplifying assumptions; thus, their applicability is limited. In this article, we show that heuristic algorithms can be successfully used in the development of very good, physical data base designs. Two heuristic optimization algorithms are proposed in the contest of a genetic and abstract model for physical design. One algorithm is based on generic principles of heuristic optimization. The other is based on capturing and using problem-specific information in the heuristics. The goodness of the algorithms is demonstrated over a wide range of problems and factor values

An Interactive DSS Tool for Physical Database Design

The design of efficient physical databases is a complex activity involving the consideration of a large number of factors. Because of the complexity, mathematical programming approaches seeking to optimize the physical database have to make many simplifying assumptions; therefore, their applicability is limited. Further, the database designer may want to experiment with design preferences and features not considered by the mathematical optimization approaches. In order to effectively design the physical database, this article describes an interactive DSS tool, which aides the database designer in this task. The database design is accomplished in the context of a high-level abstract model which is capable of being implemented in a variety of DBMSs and file systems. Because of this generic nature of the abstract model, the utility of the DSS tool is enhanced. The interactive tool not only lets the designer experiment with his own designs, but also provides several heuristic optimization procedures to enable the generation of many good designs. The heuristic designs may be used for final physical database design as well as for further experimentation. The paper also includes examples of how the physical design selected using the abstract model and the interactive tool may be implemented on several DBMSs and file systems

A temporal and spatial locality theory for characterizing very large data bases

Bibliography: p. 22-23.Stuart E. Madnick, Allen Moulton

Binary Relation Database BIRD: Issues of Representation and Implementation

This thesis presents a study of two issues, integrity and homogeneity of information representation, within the area of databases. Treatments of these issues were studied within the standard and semantic database models, leading to the proposal of a new model, the Binary Relation Database, BIRD. The BIRD model uses the binary relationship as the basis for the representation of all database data and meta-data. The inadequacy of integrity definition faculties within current database technology areelaborated in this thesis and were taken into account in the BIRD system. The effects of inhomogeneity of database data and meta-data in current databases are described and the benefits of the homogeneity of information representation in BIRD demonstrated. BIRD was implemented as a prototype database system; using Modula-2, - the implementation and subsequent evaluation of the system are included in this thesis. A simple user menu driven user interface to BIRD was constructed, - the user may manipulate information at any conceptual level in the system in a homogeneous manner. The user is free to manipulate information from any conceptual level at anytime; - BIRD ensures that the database is returned to a consistent state before the next operation may take place. The new model proposed in this thesis fulfilled its objectives, - suggestions for further and implementation oriented work are presented at the end of the thesis

Decision Support Systems: Issues and Challenges; Proceedings of an International Task Force Meeting, June 23-25, 1980

This book reports on a three-day meeting on Decision Support Systems held at IIASA. IIASA's interest in sponsoring the meeting was spurred by several factors. First, the term DSS clearly is used in a wide range of contexts; we hoped to develop a deeper understanding of the term and the new field to which it refers. Second, we felt that ongoing work in the DSS field would be enhanced by interaction between professionals who had been working on such systems and people from fields that function as "resource disciplines" for DSS. Finally we wished to bring professionals from several nations together, from the east as well as the west, to share experiences and to assess the viability of the DSS concept in different cultures. The broad objectives set for this meeting were realized in a number of ways. Virtually all the participants testified that they had gained a deeper understanding of DSS, the role it can play in asssisting managers in organizations, and the need for further development in key areas