[1991] Proceedings. Seventh International Conference on Data Engineering

8-12 April 1991

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Displaying Results 1 - 25 of 78
  • Proceedings. Seventh International Conference on Data Engineering (Cat. No.91CH2968-6)

    Publication Year: 1991
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    Freely Available from IEEE
  • Exploiting parallelism in the implementation of AGNA, a persistent programming system

    Publication Year: 1991, Page(s):660 - 669
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (740 KB)

    A design for AGNA, a persistent object system that utilizes parallelism in a fundamental way to enhance performance, is presented. The underlying thesis is that fine-grained parallelism is essential for achieving scalable performance on parallel multiple instruction/multiple data (MIMD) machines. This, in turn, implies a data-driven model of computation for efficiency. The complete design based on... View full abstract»

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  • Precomputation in a complex object environment

    Publication Year: 1991, Page(s):652 - 659
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (620 KB)

    Certain analytical results are established about precomputation in a complex object environment. The concept of `intervals' is introduced and it is shown that object-identifier caching might be beneficial provided the frequency of updates to the set of subobjects associated with an object is not too high. However, in most cases, procedures with value caching outperformed other forms of representat... View full abstract»

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  • An effective algorithm for parallelizing hash joins in the presence of data skew

    Publication Year: 1991, Page(s):200 - 209
    Cited by:  Papers (21)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (976 KB)

    A parallel hash join algorithm based on the concept of hierarchical hashing is proposed to address the problem data skew. The proposed algorithm adds an extra scheduling phase to the usual hash and join phases. During the scheduling phase, a heuristic optimization algorithm, using the output of the hash phase, attempts to balance the load across the multiple processors in the subsequent join phase... View full abstract»

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  • Incremental restart [database management]

    Publication Year: 1991, Page(s):640 - 648
    Cited by:  Papers (1)  |  Patents (57)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (792 KB)

    A page-based incremental restart algorithm is proposed that enables resuming transaction processing immediately after recovering from a crash. Data items are recovered individually and according to the demands of the post-crash transactions. The support that such an algorithm needs in terms of nonvolatile RAM and efficient log retrieval methods is outlined. It is discussed how to construct high-le... View full abstract»

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  • Perfect hashing functions for hardware applications

    Publication Year: 1991, Page(s):464 - 470
    Cited by:  Papers (3)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (444 KB)

    Perfect hashing functions are determined that are suitable for hardware implementations. A trial-and-error method of finding perfect hashing functions is proposed using a simple universal2 class (H3) of hashing functions. The results show that the relative frequency of perfect hashing functions within the class H3 is the same as predicted by the analysis for the se... View full abstract»

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  • Parallel computation of direct transitive closures

    Publication Year: 1991, Page(s):192 - 199
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (524 KB)

    To efficiently process recursive queries in a DBMS (database management system), a parallel, direct transitive closure algorithm is proposed. Efficiency is obtained by reorganizing the computation order of Warren's algorithm. The number of transfers among processors depends only on the number of processors and does not depend on the depth of the longest path. The evaluation shows an improvement du... View full abstract»

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  • Conflict-driven load control for the avoidance of data-contention thrashing

    Publication Year: 1991, Page(s):632 - 639
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (904 KB)

    A conflict-driven approach to automatic load control is presented. Various definitions of conflict rate are investigated as to whether they are suitable as a control metric. Evidence is provided that there exists at least one suitable metric and a single value, called the critical conflict rate, that indicates data-contention (DC) thrashing regardless of the number or types of transactions in the ... View full abstract»

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  • Efficient implementation techniques for the time index

    Publication Year: 1991, Page(s):102 - 111
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (620 KB)

    A new indexing technique, time index, for improving the performance of certain classes of temporal queries was previously described by the author (see The 16th Conference on Very Large Databases (1990)). Three variations for implementing the time index efficiently are proposed and the performance of these three variations is compared with the performance of the original time index. Various paramet... View full abstract»

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  • A semantic integrity framework: set restrictions for semantic groupings

    Publication Year: 1991, Page(s):710 - 717
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (704 KB)

    Three of the most common fundamental groupings that are utilized in semantic database models are considered: set groupings, power set groupings, and Cartesian aggregation groupings. For each, useful restrictions that control its structure and composition are defined. This permits each grouping to capture more subtle distinctions of the concepts or situations in the application environment. The res... View full abstract»

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  • Processing of multiple processing queries in distributed databases

    Publication Year: 1991, Page(s):42 - 49
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (584 KB)

    A set of algorithms is described that can be used to reduce the complexity of evaluating multiple queries of a transaction in a distributed environment. With the consideration of conjunct sharing, it compiles a set of queries into a network based on the concept of semijoins. As some of the queries in a transaction may change the contents of a database, evaluation of the network corresponding to th... View full abstract»

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  • An efficient semantic query optimization algorithm

    Publication Year: 1991, Page(s):326 - 335
    Cited by:  Papers (9)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (728 KB)

    An efficient semantic query optimization algorithm is proposed, in which all possible transformations are tentatively applied to the query. Instead of physically modifying the query, the transformation process classifies the predicates into imperative, optional or redundant. At the end of the transformation process, all the imperative predicates are retained while the redundant predicates are elim... View full abstract»

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  • Query pairs as hypertext links

    Publication Year: 1991, Page(s):456 - 463
    Cited by:  Papers (3)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (552 KB)

    A new idea is proposed for constructing object-oriented hypertext database systems: query pairs as hypertext links, where each query is defined over a collection of document objects that are classified using a class hierarchy. With this idea, users need not modify their hypertext links against the insertions, deletions and updates of document objects. Also, when a database schema (here, a class hi... View full abstract»

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  • Navigation and schema transformations for producing nested relations from networks

    Publication Year: 1991, Page(s):181 - 190
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (724 KB)

    Efficient procedures for producing nested relations from networks are considered. Various types of nested relations are defined according to the interaction between the networks' and nested relations' schemas. Among these types, partitional normal form (PNF) and accordant nested relations are shown to be produced by an extended navigation, called touch information display (TID) navigation, which r... View full abstract»

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  • Optimal buffer allocation in a multi-query environment

    Publication Year: 1991, Page(s):622 - 631
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (900 KB)

    The concepts of memory consumption and return on consumption (ROC) are used as the basis of memory allocations. A global optimization strategy using simulated annealing is developed which minimizes the average response time over all queries under the constraint that the total memory consumption rate has to be less than the buffer size. It selects the optimal join method and memory allocation for a... View full abstract»

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  • Wait depth limited concurrency control

    Publication Year: 1991, Page(s):92 - 101
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (800 KB)

    A new class of wait depth limited (WDL) concurrency control (CC) methods is described. The WDL policy is shown by simulations to be effective both in systems with proportionately large I/O latencies as well as in systems with large numbers of processors. WDL is also attractive in terms of implementation. In many applications little or no system modification may be required other than the CC code. ... View full abstract»

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  • Execution plan balancing

    Publication Year: 1991, Page(s):698 - 706
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (772 KB)

    A novel relational query optimization technique for use in shared memory multiprocessor database systems is described. A collection of practical algorithms for allocating computational resources to parallel select-project filter (SPJ) query execution plans is presented. The computational resources considered include disk bandwidth, memory buffers and general-purpose processors. The goal of the all... View full abstract»

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  • Efficiently maintaining availability in the presence of partitionings in distributed systems

    Publication Year: 1991, Page(s):34 - 41
    Cited by:  Papers (9)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (744 KB)

    A new approach is presented for handling partitionings in replicated distributed databases. Mechanisms are developed through which transactions can access replicated data objects and observe delays similar to nonreplicated systems while enjoying the availability benefits of replication. The replication control protocol, called VELOS, achieves optimal availability, according to a well-known metric,... View full abstract»

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  • On serializability of multidatabase transactions through forced local conflicts

    Publication Year: 1991, Page(s):314 - 323
    Cited by:  Papers (45)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (760 KB)

    A multidatabase transaction management mechanism called the optimistic ticket method (OTM) is introduced for enforcing global serializability. It permits the commitment of multidatabase transactions only if their relative serialization order is the same in all participating local database systems (LDBSs). OTM requires the LDBSs to guarantee only local serializability. The basic idea in OTM is to c... View full abstract»

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  • Object versioning in Ode

    Publication Year: 1991, Page(s):446 - 455
    Cited by:  Papers (9)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (768 KB)

    In designing the versioning facility in Ode, a few but semantically sound and powerful concepts are introduced that allow implementation of a wide variety of paradigms. Some of the salient features of these versioning facilities are the following: (1) object versioning is orthogonal to type; (2) reference to an object can be bound statically to a specific version of the object or dynamically to wh... View full abstract»

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  • An efficient hybrid join algorithm: a DB2 prototype

    Publication Year: 1991, Page(s):171 - 180
    Cited by:  Papers (13)  |  Patents (17)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (832 KB)

    A new join method, called hybrid join, is proposed which uses the join-index filtering and the skip sequential prefetch mechanism for efficient data access. With this method, the outer table is sorted on the join column. Then, the outer is joined with the index on the join column of the inner. The inner tuple is represented by its surrogate, equivalent of its physical disk address, which is carrie... View full abstract»

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  • A methodology for benchmarking distributed database management systems

    Publication Year: 1991, Page(s):612 - 619
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (572 KB)

    A methodology for benchmarking distributed database management systems is proposed. A distributed environment is characterized in terms of the communication costs incurred in data movement between sites, the number of nodes that participate in processing a query and the data distribution scheme used in the network. These three major characteristics form a basis for eight query types that capture t... View full abstract»

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  • An analysis technique for transitive closure algorithms: a statistical approach

    Publication Year: 1991, Page(s):728 - 735
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (628 KB)

    A novel experimental procedure, based on a standard statistical estimation procedure, is presented to estimate the performance of transitive closure algorithms. This experimental procedure has been exemplified in three contexts: (1) comparison of a suite of algorithms: (2) analysis of one particular algorithm; and (3) analysis of the transitive closure problem itself. It is shown that the number o... View full abstract»

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  • Interactive manipulation of object-oriented views

    Publication Year: 1991, Page(s):60 - 69
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (652 KB)

    An approach to providing view support in object-oriented (O2 ) databases is presented. The approach uses what is called a hyper-view and combines results from research on database design and man-machine interfaces. A mechanism that allows interacting with databases through hyper-views and built on top of the O2 system is described. The approach is based on conciliating stored... View full abstract»

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  • A knowledge-based subsystem for a natural language interface to a database that predicts and explains query failures

    Publication Year: 1991, Page(s):80 - 87
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (664 KB)

    A practical method is presented for eliminating unnecessary database operations that often arise from poorly posed natural language queries. This subsystem consists mainly of a knowledge-base whose rules are semantic constraints of the database. The inference procedure's actions are, unlike that of similar inference engines, strictly controlled by the structure of the query. Because of this it is ... View full abstract»

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