An Introduction to Database Systems

This textbook introduces the basic concepts of database systems. These concepts are presented through numerous examples in modeling and design. The material in this book is geared to an introductory course in database systems offered at the junior or senior level of Computer Science. It could also be used in a first year graduate course in database systems, focusing on a selection of the advanced topics in the latter chapters

A machine independent implementation of a data storage description language.

This thesis presents the methods, results and conclusions of a design and implementation of a Data Storage Description Language (DSDL). The DSDL chosen was the CODASYL Network DSDL. The design supports storage independent manipulation, for access and reorganisation of partitioned schema records, sets and indexes. The production of a Table Generator to compile the DSDL provided the basic structure and mechanisms of a run-time system for the support of dynamic incremental reorganisation. The project developed storage constructs and techniques for a machine independent Data Storage Description Language and evaluated these ideas through an implementation.The particular objectives of the project included the evaluation of the efficiency of the techniques regarding the criteria of the storage space of tables and records, time for processing, and ease of reorganisation. By developing a run-time system to control dynamic reorganisation of a database given a new version of the storage schema for the same database

Information technology and distance learning aspects of materials databases

Distance learning is a flourishing area, with the number of programs, provided via remote delivery, increasing daily. At the same time, however, progress in the field of accessibility and support for learners, who want to pursue education and training in the area of materials science and engineering, has not always kept pace. An individual interested in taking a materials course, or in simply finding out what is available, may find himself/herself forced to locate and then plough through many unwieldy online course listings. This may discourage many learners from pursuing the distance learning option. In recent years, more and more distance learning databases have been developed and made available on the World Wide Web. These distance-learning databases are aimed to offer an information pool on many courses and programs that are available online and to cater for users' specific needs of locating information. This need is equally applicable to the area of materials science and engineering. The purpose of this current research has been to explore Information and Technology aspects of materials databases and closely study distance learning aspects. [Continues.

A comparative study of structured and un-structured remote data access in distributed computing systems

Recently, the use of distributed computing systems has been growing rapidly due to the result of cheap and advanced microelectronic technology. In addition to the decrease in hardware costs, the tremendous development in machine to machine communication interfaces, especially in local area networking, also favours the use of distributed systems. Distributed systems often require remote access to data stored at different sites. Generally, two models of access to remote data storage exist: the un structured and structured models. In the former, data is simply stored as row of bytes, whereas in the latter, data is stored along with the associated access codes. The objective of this thesis is to compare these two models and hence determines the tradeoffs of each model. First of all, an extended review of the field of distributed data access is provided which addressing key issues such as the basic design principles of distributed computing systems, the notions of abstract data types, data inheritance, data type system and data persistence. Secondly, a distributed system is implemented using the persistent programming language PS-algol and the high level language C in conjunction with the remote procedure call facilities available in Unix(^1) 4.2 BSD operating system. This distributed system makes extensive use of Unix's software tools and hence it is called DCSUNIX for Distributed Computing System on UNIX. Thirdly, two specific applications which employ the implemented system will be given so that a comparison can be made between the two remote data access models mentioned above. Finally, the implemented system is compared with the criteria established earlier in the thesis. keywords: abstract data types, class, database management, data persistence, information hiding, inheritance, object oriented programming, programming languages, remote procedure calls, transparency, and type checking

Engineering and Scientific Data Management

The application of data management systems to engineering and scientific data is described

Viaduct : an interactive, very-high-level data manipulation language for a microcomputer-based database system.

Bibliography: leaves 203-210.A very-high-level data manipulation language for a database system is one in which the user specifies in non-procedural terms the operations that are to be performed on the data stored in the database; the actual method by which the operations are executed does not concern the user. VIADUCT provides such an interface to a microcomputer-based database system known as MDBS. Thus VIADUCT allows a microcomputer user lacking in computer sophistication to interact with, and derive the benefits of, a powerful database management system. Additional security restrictions and integrity constraints usually found only on mainframe database management systems are provided by VIADUCT through the mechanism of a subschema generator

Multi-level concurrency control of a database system

A typical database system maintains target data, which contain information useful for users, and access path data, which facilitate faster accesses to target data. Further, most large database systems support concurrent processing of multiple transactions. For a static database system model, where units of concurrency control are not dynamically created or deleted, various concurrency control methods are known. Also, many methods that allow concurrent accesses to indexing structures without invalidating their integrity are known. However, a straightforward integration of these two kinds of concurrency control methods fails because of the phantom problem. In this paper, we introduce group locks in order to solve this problem and discuss their implementation. As one side benefit of introducing group locks, we show that if the lowest-level access path data as well as the target data are two-phase locked by transactions, consistency of the logical data will be preserved