92 research outputs found

    The multi-lingual database system

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    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

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

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    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

    New Directions In Database-Systems Research and Development

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    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

    Information sharing and security in dynamic coalitions

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    CONSTRAINT BASED ANALYSIS OF DATABASE UPDATE PROPAGATION

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    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

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    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

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    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

    The implementation of a multi-backend database system (MDBS), part III: The message-oriented version with concurrency control and secondary-memory-based directory management

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    The multi-backend database systems (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 implemented in order to carry out design verification and performance evaluation. This report is the third in a series which describes the MDBS implementation. In the report, an overview of MDBS and its process structure is first given. Then, the inter-process communication (messages between processes within a minicomputers, i.e.the controller and a backend or any two backends) are describedPrepared for: Chief of Naval Research; Arlington, VA 22217.http://archive.org/details/implementationof00boynN

    Assessment of candidate information models for granular computing

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