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[1990] Proceedings. Sixth International Conference on Data Engineering

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
  • A suitable algorithm for computing partial transitive closures in databases

    Publication Year: 1990, Page(s):264 - 271
    Cited by:  Papers (15)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (732 KB)

    The computation of partial transitive closures is considered as an elementary operation for implementing deductive database systems. A new algorithm supporting this operation is presented. Unlike previously published algorithms, which are based on either matrix manipulations or depth-first search strategy, the algorithm presented uses breadth-first search as its dominant traversal strategy, a grap... View full abstract»

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  • Join index, materialized view, and hybrid-hash join: a performance analysis

    Publication Year: 1990, Page(s):256 - 263
    Cited by:  Papers (12)  |  Patents (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (692 KB)

    The problem of efficiently computing a joint between two base relations in the presence of queries and updates to the base relations is dealt with. A performance analysis of three methods: join index, materialized view, and hybrid-hash join, is presented. The first two methods are examples of a strategy based on data caching; they represent two ends of a spectrum of possibilities depending on the ... View full abstract»

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  • Concurrency control of bulk access transactions on shared nothing parallel database machines

    Publication Year: 1990, Page(s):476 - 485
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    New concurrency control schemes are proposed for bulk access transactions (BATs) on shared-nothing database machines. A BAT is a transaction accessing a large bulk of data, such as a transaction updating a whole file. BATs are used for batch jobs in database services, and many BATs should be finished in a short time. Thus it is necessary to execute BATs concurrently on a database machine. When sch... View full abstract»

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  • Performance evaluation of multiversion database systems

    Publication Year: 1990, Page(s):129 - 136
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    A description is given of a detailed simulation study of the performance of multiversion database systems. The characteristics and the extent to which they provide performance benefits over their single-version counterparts are investigated. First, the structure of a software prototyping environment for the evaluation of distributed database systems is presented. Using this environment, the author... View full abstract»

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  • System issues in parallel sorting for database systems

    Publication Year: 1990, Page(s):246 - 255
    Cited by:  Papers (10)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (940 KB)

    An external parallel merge-sort and sort-merge join on tightly coupled processors is considered. The issue of whether significant speedup can be achieved with good CPU efficiency is addressed. A pure sort query and a five-relation join query using a sort-merge-join algorithm are examined. It is found that the external sort is readily parallelizable. In the absence of skew, a speedup, linear in the... 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 (19)
    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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  • Database buffer model for the data sharing environment

    Publication Year: 1990, Page(s):538 - 544
    Cited by:  Papers (8)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    A simple analytic buffer model for coupled systems sharing a common database is developed. When a data block gets updated by a system, copies of that block in other systems' buffers need to be invalidated. This cross-invalidation phenomenon makes the estimation of the buffer hit ratio interesting. The concurrency control (CC) scheme can also complicate the situation. Under the optimistic CC protoc... View full abstract»

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  • Scheduling data redistribution in distributed databases

    Publication Year: 1990, Page(s):166 - 173
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    In a distributed database system there is a need for periodic changes in data distribution due to such factors as changes in query patterns and network topology. A proper redistribution of data is necessary to provide acceptable system performance, as measured by the average execution time of transactions. The problem of properly scheduling data transfers in order to complete this redistribution p... View full abstract»

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  • Parallelism in database production systems

    Publication Year: 1990, Page(s):121 - 128
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (652 KB)

    A study is made of the issues in parallelizing database production systems. Various kinds of parallelism possible in production systems are classified. Parallel execution of production systems leads to some subtle problems which, if not handled carefully, can cause altered execution semantics. The precise conditions that any parallel implementation of production systems must fulfil in order to be ... View full abstract»

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  • Object views: Extending the vision

    Publication Year: 1990, Page(s):86 - 93
    Cited by:  Papers (29)  |  Patents (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (724 KB)

    A mechanism for producing views in an object-oriented system is presented. The results are analogous to database views in traditional database systems, except that the object views presented hide or expose methods as well as data. The mechanism is based on the object model's built-in facilities for defining data and procedural abstractions and for constructing new types and objects. It uses the ty... View full abstract»

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  • Bill-of-material configuration generation

    Publication Year: 1990, Page(s):237 - 244
    Cited by:  Papers (4)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (596 KB)

    A novel system which combines elements of database management, object-oriented technology and artificial intelligence is described. This system addresses certain bill-of-material (BOM) configuration generation problems and should not be confused with the more typical BOM recursive traversal problems. The BOM configuration system automatically extracts design rules from existing BOM designs. The sy... View full abstract»

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  • Chained declustering: a new availability strategy for multiprocessor database machines

    Publication Year: 1990, Page(s):456 - 465
    Cited by:  Papers (73)  |  Patents (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (936 KB)

    A new strategy for increasing the availability of data in multiprocessor, shared-nothing database machines is presented. This technique, termed chained declustering, is demonstrated to provide superior performance in the event of failures while maintaining a very high degree of data availability. Furthermore, unlike most earlier replication strategies, the implementation of chained declustering re... View full abstract»

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  • Access invariance and its use in high contention environments

    Publication Year: 1990, Page(s):47 - 55
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (780 KB)

    Various factors suggest that data contention may be of increasing significance in transaction processing systems. One approach to this problem is to run transactions twice, the first time without making any changes to the database. Benefits may result either from data prefetching during the first execution or from determining the locks required for purposes of scheduling. Consideration is given to... View full abstract»

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  • Propagating updates in a highly replicated database

    Publication Year: 1990, Page(s):529 - 536
    Cited by:  Papers (3)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (692 KB)

    Consideration is given to the problem of propagating messages to a large number of hosts in a distributed database. The work of propagating the message is distributed and minimized among the hosts by arranging them into a minimum-cost spanning tree. Only the cooperation of the hosts that belong to the database is required. Transient and permanent failures are handled in this protocol. Eventual del... 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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  • 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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  • Query processing for temporal databases

    Publication Year: 1990, Page(s):200 - 208
    Cited by:  Papers (13)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (664 KB)

    A stream processing approach for temporal query processing and optimization is discussed. Given properly sorted data, the implementation of temporal joins and semijoins as stream processors can be very effective. Also discussed are the tradeoffs among sort orders, the amount of local workspace, and multiple scans over input streams; in particular, the authors are interested in the effect of sort o... View full abstract»

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  • The generalized grid file: description and performance aspects

    Publication Year: 1990, Page(s):380 - 388
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (632 KB)

    The grid file offers multiattribute access and is a structure proposed for geometrical applications. This means that so-called point, partial match, partial range and range queries for the concerned attributes are supported. The generalized grid file (GGF), which offers fast access for a single attribute too, is described. The performance of the GGF structure is evaluated for the business environm... View full abstract»

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  • An object-oriented approach to data/knowledge modeling based on logic

    Publication Year: 1990, Page(s):289 - 294
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (528 KB)

    The object-oriented data model has gained popularity in developing database systems for new applications which include AI, CAD, and OIS. In modeling such applications, it is necessary to capture not only data semantics but also knowledge semantics, such as constraints and deductive rules. The authors describe an approach to data/knowledge modeling which combines various modeling features of the ob... View full abstract»

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  • A query algebra for object-oriented databases

    Publication Year: 1990, Page(s):154 - 162
    Cited by:  Papers (50)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (740 KB)

    An algebra that synthesizes relational query concepts with object-oriented databases is defined. The algebra fully supports abstract data types and object identity, while providing associative access to objects. The operations take an abstract view of objects and access typed collections of objects through the public interface defined for the type. The algebra supports access to relationships impl... View full abstract»

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  • Serializability in object-oriented database systems

    Publication Year: 1990, Page(s):112 - 120
    Cited by:  Papers (8)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    In an object-oriented database the objects are encapsulated, that is, objects are only accessible by methods defined in the database system. The definition of object-oriented serializability takes advantage of the semantics and of the nesting of the methods. Therefore, a lower rate of conflicting accesses than with the conventional definition of serializability is achieved. Transactions of an obje... 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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  • Modeling design object relationships in PEGASUS

    Publication Year: 1990, Page(s):228 - 236
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (908 KB)

    A description is given of the preliminary data model design of a database system for CAD applications named Pegasus. The model is based on previously published work on extensible and object-oriented database systems. Novel ideas of the model that are presented include the use of relationship objects as a modeling construct to represent relationships of any degree, and replication and the reconcili... 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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