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Data Engineering, 1990. Proceedings. Sixth International Conference on

Date 5-9 Feb. 1990

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Displaying Results 1 - 25 of 66
  • Sixth International Conference on Data Engineering (Cat. No.90CH2840-7)

    Publication Year: 1990
    Request permission for commercial reuse | PDF file iconPDF (142 KB)
    Freely Available from IEEE
  • Currency-based updates to distributed materialized views

    Publication Year: 1990, Page(s):512 - 520
    Cited by:  Papers (5)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (656 KB)

    In currency-based updates, processing a query to a materialized view has to satisfy a currency constraint which specifies the maximum time lag of the view data with respect to a transaction database. Currency-based update policies are more general than periodical, deferred, and immediate updates; they provide additional opportunities for optimization and allow updating a materialized view from oth... View full abstract»

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  • Experiences with distributed query processing

    Publication Year: 1990, Page(s):192 - 199
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    Different implementations of an experimental distributed query processing system which is constructed on top of existing database management systems (DBMSs) are presented. A performance evaluation is carried out. It is shown that the response times of query execution are affected significantly by the degree of site autonomy, interferences among processes, interface with the local DBMSs, and commun... View full abstract»

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  • A shared conceptual schema for four medical expert systems

    Publication Year: 1990, Page(s):410 - 419
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (896 KB)

    The fundamental reason for database management systems is the support of applications using shared overlapping sets of data through external views of an underlying conceptual schema. The definition of such a schema for expert systems (ESs) is a topic of interest to database researchers both as a proof that ESs can be supported and as an exploration of the process of view integration. A shared conc... View full abstract»

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  • Attribute inheritance implemented on top of a relational database system

    Publication Year: 1990, Page(s):503 - 509
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    An implementation technique which solves integrity checking, query evaluation, and transaction synchronization tasks in database systems with multiple attribute inheritance and uses the support of a relational database system is presented. It is shown how to implement an integrity checker and a transaction synchronization component of a database system with attribute inheritance. The basic idea is... View full abstract»

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  • Experimental evaluation of concurrent checkpointing and rollback-recovery algorithms

    Publication Year: 1990, Page(s):182 - 189
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (732 KB)

    The performance of two distributed checkpointing and recovery algorithms, the synchronous checkpointing algorithm (SA) and the independent checkpointing algorithm (ICA), is evaluated. The performance is based on a detailed implementation of algorithms published earlier in the C language. A benchmark that simulates a variety of application requirements and considers variations in the number of proc... View full abstract»

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  • A `greedy' approach to the write problem in shadowed disk systems

    Publication Year: 1990, Page(s):553 - 558
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    There has been considerable interest in parallel disk drive systems, in which replication of the stored data is used for both fault tolerance and enhanced performance. It has been discovered that performance gains are limited by the fact that no matter how large the number of disk drives, the system still behaves probabilistically like a small system. These findings are summarized, and a greedy, t... View full abstract»

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  • Multi-user view integration system (MUVIS): an expert system for view integration

    Publication Year: 1990, Page(s):402 - 409
    Cited by:  Papers (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (668 KB)

    A description is given of the architecture and development of a knowledge-based system called MUVIS (multiuser view integration system) to support the design of distributed object-oriented databases. MUVIS is implemented using an object-oriented development environment. It assists database designers in representing user views and integrating these views into a global conceptual view. The view inte... View full abstract»

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  • Selectivity estimation using homogeneity measurement

    Publication Year: 1990, Page(s):304 - 310
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    A new approach is presented for organizing a large collection of multidimensional data with an unknown distribution by partitioning the data such that the data are relatively homogeneously distributed in each block. A multidimensional tree is generated according to this partition. After the tree is generated, summary data estimation such as selectively estimation can be performed via a tree search... View full abstract»

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  • How to share work on shared objects in design databases

    Publication Year: 1990, Page(s):575 - 583
    Cited by:  Papers (5)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (704 KB)

    Designers in CAD environments typically perform long-duration modifications of completely structure objects and work cooperatively in design teams. Several forms of design transactions for nonstandard database systems have been proposed as a mechanism to support their kind of operational pattern. They are partitioned by checkout/check-in operations and/or divided into several kinds of subtransacti... View full abstract»

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  • Representing processes in the extended entity-relationship model

    Publication Year: 1990, Page(s):103 - 110
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    Although closely related, functional and structural aspects of information systems are usually modeled independently of each other. The author proposes to combine functional and structural modeling into an integrated design methodology. He chooses for this purpose two popular and widely used models, the data-flow-oriented functional model and the extended entity-relationship (EER) data model. Sinc... View full abstract»

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  • On representing indefinite and maybe information in relational databases: a generalization

    Publication Year: 1990, Page(s):495 - 502
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    The authors present a generalization of the relational model to represent indefinite and maybe kinds of incomplete information. They introduce a data structure called M-table which is capable of representing disjunctive/indefinite and maybe facts. The notion of redundancy in the context of indefinite and maybe information is studied. The information content of an M-table is precisely defined. The ... View full abstract»

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  • A temporal model and query language for ER databases

    Publication Year: 1990, Page(s):76 - 83
    Cited by:  Papers (19)  |  Patents (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    A temporal extension to an extended ER (entity-relationship) model is proposed. The concept of life span for entities and relationships is incorporated in the ER model. Also specified is a temporal query and update language which is an extension of the GORDAS language. The concepts of temporal Boolean expressions, temporal selection, and temporal projection are introduced, and their use in the que... View full abstract»

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  • Cost of distributed deadlock detection: a performance study

    Publication Year: 1990, Page(s):174 - 181
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (652 KB)

    A performance evaluation of two classes of distributed deadlock detection algorithms, namely, set-based and probe-based distributed deadlock detection algorithms, is presented. The performance evaluation is performed on a simulated distributed database by implementing the algorithms. The performance evaluation shows two main results. First, set-based algorithms outperform probe-based algorithms. S... View full abstract»

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  • Buffer and load balancing in locally distributed database systems

    Publication Year: 1990, Page(s):545 - 552
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    The authors investigated the effectiveness of load balancing when the buffer space requirement and the availability of buffers at different database sites are considered. New load-balancing algorithms are proposed and a simulation study was conducted. The results indicate that, by considering buffer space as a major system resource, load balancing is still an effective approach to improving system... View full abstract»

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  • A multiuser performance analysis of alternative declustering strategies

    Publication Year: 1990, Page(s):466 - 475
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (836 KB)

    An analysis is made of the impact of three alternative declustering strategies on the performance of the selection queries using different storage/access structures in a multiuser environment. The authors quantify the tradeoffs of each organization in the context of the Gamma database machine. The response time and throughput of the system are used as the performance metric for evaluating the alte... View full abstract»

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  • A partitioned signature file structure for multiattribute and text retrieval

    Publication Year: 1990, Page(s):389 - 396
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (652 KB)

    A partitioning method is introduced for reducing the search space required on the signature file. A partitioned signature file is better than the multilevel signature file and the S-tree in that it has an extremely small storage and processing overhead. Three partitioning schemes are outlined and their performance discussed. A description is given of the data structure necessary to support the par... View full abstract»

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  • A new tree type data structure with homogeneous nodes suitable for a very large spatial database

    Publication Year: 1990, Page(s):296 - 303
    Cited by:  Papers (3)  |  Patents (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    A new dynamic data structure for spatial retrieval called a GBD tree is proposed. The GBD tree is systematically constructed using homogeneous nodes with a small amount of extra data called a DZ expression which plays an important role in efficient multiway recursive division of N-dimensional space. On the GBD tree, CPU cost during insertion and deletion is much smaller than on an R-tree,... View full abstract»

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  • Long-duration transactions in software design projects

    Publication Year: 1990, Page(s):568 - 574
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (684 KB)

    An example of a software development application is considered, and the formal model of H. Korth and G. Speegle (1988) is applied to show how this example could be represented as a set of database transactions. It is shown that, although the standard notion of correctness (serializability) is too strict, the notion of correctness in the Korth and Speegle model allows sufficient concurrency with ac... View full abstract»

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  • The semantic data model for security: representing the security semantics of an application

    Publication Year: 1990, Page(s):322 - 329
    Cited by:  Papers (8)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (844 KB)

    Data security requirements go beyond traditional access control considerations to include relationships among data that must be protected. The author extends the data-modeling concepts to include the secrecy properties of data. The semantic data model for security (SDMS) is proposed as the vehicle for users, database designers and security officers to analyze and understand the security requiremen... View full abstract»

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  • Using a metamodel to represent object-oriented data models

    Publication Year: 1990, Page(s):11 - 19
    Cited by:  Papers (3)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    A metamodel for describing the semantics of object-oriented data models is presented. This metamodel supports the automatic generation of conceptual database design tool software for a variety of data models. Data modeling is viewed as having three levels of abstraction. The physical database, at the lowest level, stores objects and relationships. Specific data models reside at the middle level. A... View full abstract»

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  • Alternatives in complex object representation: a performance perspective

    Publication Year: 1990, Page(s):94 - 102
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (788 KB)

    With database systems finding wider use in CAD, office information systems, and logic programming applications, the importance of efficiently representing and manipulating complex objects is growing. In this study a classification of the alternatives for representing complex objects is examined. Consideration is given to the performance aspects of one representation technique based on object ident... View full abstract»

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  • Extended relations

    Publication Year: 1990, Page(s):488 - 494
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB)

    A description is given of extended relations, a generalization of ordinary relations in which tuple identifiers (tids) can appear as attribute values. The relational algebra is extended to include new operators that manipulate these tids; the resulting algebra is called the tid-algebra. The theorems of the tid-algebra are shown to provide a formal basis for optimizer transformations that involve h... View full abstract»

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  • ViewSystem: integrating heterogeneous information bases by object-oriented views

    Publication Year: 1990, Page(s):2 - 10
    Cited by:  Papers (33)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    In order to overcome practical integration problems, ViewSystem, an object-oriented programming environment with dedicated integration operators by which syntactically and semantically heterogeneous information can be integrated incrementally, has been developed. ViewSystem provides an object-oriented query language and a method language with universal computational power and a distinguished set o... View full abstract»

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  • Supporting universal quantification in a two-dimensional database query language

    Publication Year: 1990, Page(s):68 - 75
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    A technique for specifying universal quantification and existential quantification (combined with negation) in a two-dimensional graphical database query language is proposed. Unlike other approaches that provide set operators to simulate universal quantification, this technique allows a direct representation of universal quantification. The authors present syntactic constructs for specifying univ... View full abstract»

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