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

A benchmarking methodology for the centralized-database computer with expandable and parallel database processors and stores

In this paper a benchmarking methodology for a new kind of database computers is introduced. The emergence in the research community and in the commercial world of this kind of database computer (known as the multiple-backed database computers), were each computer system is configured with two or more identical processors and their associated stores for concurrent execution of transactions and for parallel processing of a centralized database spread over separate stores, is evident. The motivation and characterization of the multiple-backend database computer are first given. The need and lack of a methodology for benchmarking the new computer with a variable number of backends for the same database or with a fixed number of backends for different capacities are also evident. The measures (benchmarks) of the new computer are articulated and established and the design of the methodology for conducting the measurements is then given. Because of the novelty of the database computer architecture, the benchmarking methodology is rather elaborate and somewhat complicated. To aid our understanding of the methodology, a concrete sample is given herein. This sample also illustrates the use of the methodology. Meanwhile, a CAD system which computerizes the benchmarking methodology for systematically assisting the design of test databases and test-transaction mixes, for automatically tallying the design data and workloads, and for completely generating the test databases and test-transaction mixes is being implementedPrepared for: Chief of Naval Research Arlington, VAhttp://archive.org/details/benchmarkingmeth00demu61153N; RRO14-0 8-01 N0001485WR24046NAApproved for public release; distribution is unlimited

CONSTRAINT BASED ANALYSIS OF DATABASE UPDATE PROPAGATION

Semantic and object-oriented data models provide convenient constructs for the specification of objects, relationships, and operations. The vehicle of representation is a collection of abstractions which parallel the means by which humans prefer to organize complex enterprises. These constructs inherently permit focus on one object, relationship, or operation at a time. Propagation, as a semantic construct, provides the extension of existing modeling capabilities by providing a mechanism for the specification of the update semantics between database objects. Through the analysis of constraints and the propagated actions necessary to maintain them, we attempt to do the following: 1) incorporate additional semantics into the database schema in the form of database propagation rules, 2) in the context of constraints and propagation rules, provide a model independent paradigm for determining if schemata are correct, and 3) provide a vehicle fur the explicit specification of update actions during database schema design

Towards an Ideal Database Server for Office Automation Environments

Office automation systems are growing but continue both in use and complexity. The evelopment of a database management system for the office automation environment ecomes a high priority, inorder to provide an efficient and reliable way to engage the information needs of the office. Therefore, the specification of an 'ideal' database server for the office automation environment becomes a key area of concern. inaddition to providing traditional support, the ideal database server must also provide new database support, in order to meet the unique and nyneedsofofficeautomationenvironments. In this paper, we focus on the characterization and specification of an ideal database server, for the office automation environment. We also consider how such an ideal database server can effectively Integrated into the office automation environment. Further, we ne an experimental database system, known as the multi-backend database system (NSDS), as a candidate for the ideal database server in the office automation environment.Chief of Naval Researc

The implementation of a multi-backend database system (MDBS): Part IV, The revised concurrency control and directory management processes and the revised definitions of inter-process and inter-computer messages

The multi-backend database system (MDBS) uses one minicomputer as the master or controller, and a varying number of minicomputers and their disks as slaves or backends. MDBS is primarily designed to provide for database growth and performance enhancement by the addition of identical backends. No special hardware is required. The backends are configured in a parallel manner. A new backend may be added by replicating the existing software on the new backend. No new programming or reprogramming is required. A prototype MDBS is being completed in order to carry out the design verification and performance evaluation. This report is the fourth in a series which describes the MDBS implementation. The processes in the MDBS controller (request preparation, insert information generation and post processing) and the processes in the MDBS backends (directory management, record processing and concurrency control) have been described in the previous reports. The concurrency control process, formerly used to control access to just user data, is modified to control access to directory data as well. The directory management process is also modified to improve the execution of update requests. Finally, a directory management is modified for the storage of directory data on the secondary storage. Next, the report describes the revised definitions of inter-process messages (messages between processes within a minicomputer) and intercomputer messages (messages between processes in different minicomputers). Finally, we conclude this series of reports dealing with the implementation of MDBSPrepared for: Chief of Naval Researchhttp://archive.org/details/implementationof00demuN00014-84-WR-24058N

Benchmarking Database Systems in Multiple Backend Configurations

The aim of this performance evaluation is twofold: (1) to devise benchmarking strategies for and apply benchmarking methodologies to the measurement of a prototyped database system in multiple backend configurations, and (2) to verify the performance claims as projected or predicted by the designer and implementor of the multi-backend database system known as MBDS. Despite the limitation of the backend hardware, the benchmarking experiments have proceeded well, producing startling results and good insights. By collecting macroscopic data such as the response time of the request, the external performance measurements of MBDS have been conducted. By collecting microscopic data such as the time entering and leaving a system process, the internal performance measurements of MBDS have been carried out. Methodologies for constructing test databases, directories, and requests have been devised and utilized. The performance evaluation studies verify that (a) when the database remains the same the response time of a request can be reduced to nearly half, if the number of backends and their disks is doubled; (b) when the response set of a request doubles, the response time of the query remains nearly constant, if the number of backends and their disks is doubled. These were the performance claims of MBDS as predicted by its designer and implementor.Chief of Naval Researc