[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
    Request permission for commercial reuse | PDF file iconPDF (478 KB)
    Freely Available from IEEE
  • Meta-reasoning: An incremental compilation approach

    Publication Year: 1991, Page(s):140 - 149
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (668 KB)

    An incremental compilation approach to meta-reasoning is presented together with a method to update dynamically changing knowledge bases. The compilation process translates meta-level specification of facts and hypotheses into sentences of clausal logic. It then incrementally computes inconsistent sets of instances of hypotheses and records potential crucial literals. The extra information compute... View full abstract»

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  • Performance measurement of some main memory database recovery algorithms

    Publication Year: 1991, Page(s):436 - 443
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    The performance of two main-memory database system (MDBS) algorithms is studied. M.H. Eich's (Proc. of the Fifth Int. Workshop on Database Machines., Oct. 1987) and T.J. Lehman's (Ph. D. Thesis, Univ. of Wisconsin-Madison, Aug 1986) algorithms are selected for this study. The investigation indicates that the shadow approach, as used by Eich, has some advantages over the update in-place strategy of... View full abstract»

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  • Inferential modelling technique for constructing second generation knowledge based systems

    Publication Year: 1991, Page(s):582 - 589
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    A novel inferential modeling technique (IMT) which aims to first clarify the domain ontology and inferences before proceeding onto the dynamic processing aspects of expertise is presented. The proposed model consists of the four levels of strategy, task, inference, and domain layers. The former two levels constitute the dynamic component and the latter two the static component. The static represen... View full abstract»

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  • Maintaining quasi serializability in multidatabase systems

    Publication Year: 1991, Page(s):360 - 367
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    A scheduler producing quasi-serializable executions for concurrency control in multidatabase systems (MDBSs) is presented. An algorithm is proposed which ensures quasi-serializability by controlling submissions of global transactions. The algorithm groups global transactions in such a way that transactions in a group affect each other in a partial order. Transaction groups are executed separately ... View full abstract»

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  • Real time retrieval and update of materialized transitive closure

    Publication Year: 1991, Page(s):690 - 697
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    A data structure is used to store materialized transitive closure such that the evaluation of transitive closure, deletions and insertions of tuples can be performed efficiently. Experiments have been carried out on a Sun/3/180 system. It is verified experimentally and theoretically that it takes on the average O(m") to retrieve the ancestors/descendants of the given node, where ... View full abstract»

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  • Natural joins in relational databases with indefinite and maybe information

    Publication Year: 1991, Page(s):132 - 139
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    Natural joins are defined, in a semantically correct way, on data structures, called I-tables, of an extended relational database model with indefinite and maybe information. An algorithm for computing natural joins under the extended model is proposed which reduces the number of pair-up operations and block accesses to a linear order of complexity with respect to the size of I-tables. Pr... View full abstract»

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  • Performance limits of two-phase locking

    Publication Year: 1991, Page(s):426 - 435
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (872 KB)

    A novel mean-value analysis method for two-phase locking (2PL) is presented which extends previous work to the important case of variable size transactions. The system performance expressed as the fraction of blocked transactions (β) is determined by solving a cubic equation in β whose coefficients are functions of a single parameter (α), which determines the degree of lock content... View full abstract»

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  • The architecture of BrAID: a system for bridging AI/DB systems

    Publication Year: 1991, Page(s):570 - 581
    Cited by:  Papers (3)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1132 KB)

    The design of BrAID (a bridge between artificial intelligence and database management systems), an experimental system for the efficient integration of logic-based artificial intelligence (AI) and databases (DB) technologies, is described. Features provided by BrAID include (a) access to conventional DBMSs, (b) support for multiple inferencing strategies, (c) a powerful caching subsystem that mana... 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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  • Optimization of generalized transitive closure queries

    Publication Year: 1991, Page(s):345 - 354
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    Two complementary techniques for optimizing generalized transitive closure queries are presented: (i) selections on paths are applied during the closure computation, so that paths that are not in the result and that are not needed to compute the result are pruned as early as possible and (ii) paths that are in the result, or needed to compute the result, are represented in a condensed form. The co... View full abstract»

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  • A polymorphic relational algebra and its optimization

    Publication Year: 1991, Page(s):680 - 689
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (780 KB)

    The notion of a polymorphic database and the optimization of polymorphic queries-specifically, optimization of queries under the Morpheus data model-is addressed. The notion of query optimization through type inference, applicable both to polymorphic databases and traditional monomorphic databases, is introduced. The Morpheus data model and its type inference rules are reviewed and a polymorphic r... View full abstract»

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  • Modeling uncertainty in databases

    Publication Year: 1991, Page(s):122 - 131
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    Relational algebra operations were extended to produce, together with answers to queries, information regarding sources that contributed to the answers. The author's previous model is reviewed and the semantic interpretation is presented. It is shown that extended relational algebra operations are precise, that is, they produce exactly the same answers that are expected under the semantic interpre... View full abstract»

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  • Performance evaluation of functional disk system (FDS-R2)

    Publication Year: 1991, Page(s):416 - 425
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (828 KB)

    The performance of the functional disk system with relational database engine (FDS-R2) is evaluated in detail in view of two points. First, the performance evaluation of the combined hash algorithm on FDS-R2 is reported using the projection and aggregation operations in addition to the join operation and they are analyzed in order to verify the effectiveness of the proposed processing method, Seco... 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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  • Lk: a language for capturing real world meanings of the stored data

    Publication Year: 1991, Page(s):738 - 745
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (664 KB)

    A knowledge representation language Lk is introduced that is tailored for expressing the real-world meanings of stored data. Lk is developed to achieve a tight coupling between a knowledge base component and the database system. Lk offers (1) a flexible descriptive power which facilitates concepts to be expressed at different levels of gr... View full abstract»

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  • Preserving and generating objects in the LIVING IN A LATTICE rule language

    Publication Year: 1991, Page(s):562 - 569
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (740 KB)

    LIVING IN A LATTICE is presented as a rule-based query language for an object-oriented database model. The model supports complex objects, object identity, and is-a-relationships. The instances are described by object relations, which are functions from a set of objects to value sets and other object sets. The rule language is based on object-terms which provide an access to objects via is-a-relat... View full abstract»

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  • Read optimized file system designs: a performance evaluation

    Publication Year: 1991, Page(s):602 - 611
    Cited by:  Papers (3)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (800 KB)

    A performance comparison is presented of several file system allocation policies. The file systems are designed to provide high bandwidth between disks and main memory by taking advantage of parallelism in an underlying disk array catering to large units of transfer, and minimizing the bandwidth dedicated to the transfer of metadata. All of the file systems described use a multiblock allocation st... 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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  • Query processing algorithms for temporal intersection joins

    Publication Year: 1991, Page(s):336 - 344
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (760 KB)

    Intersection join processing in temporal relational databases is investigated. An analysis is presented of the characteristics and processing requirements of three types of intersection join operators: the time-join temporal equijoin on the surrogate, and temporal equijoin on the temporal attribute. Based on the physical organization of the database and on the semantics of the operators, several a... View full abstract»

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  • Distributed query optimization by one-shot fixed-precision semi-join execution

    Publication Year: 1991, Page(s):756 - 763
    Cited by:  Papers (8)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    A novel semijoin execution strategy is proposed which allows parallelism and processes multiple semijoins simultaneously. In practice most of the parameters needed for query optimization, such as relation cardinality and selectivity, are of fixed-precision. Imposing this fixed-precision constraint, an efficient distributed query processing algorithm is developed. For situations where the fixed-pre... View full abstract»

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  • How spacey can they get? Space overhead for storage and indexing with object-oriented databases

    Publication Year: 1991, Page(s):14 - 22
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    The impact of physical storage model choice on the performance of an object-oriented database is studied. It is examined how each of six physical storage models' space overhead reacts to changes in database parameters such as directed acrylic graph (DAG) shape, number of instances per class, and distribution of instances over the DAG. Home-class, leaf-overlap, and split-instance physical models co... 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 evaluation framework for algebraic object-oriented query models

    Publication Year: 1991, Page(s):670 - 677
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (800 KB)

    An evaluation framework consisting of five categories of criteria is developed for evaluating the relative merits of objects algebras, namely, object-orientedness, expressiveness, formalness, performance and database issues. Four recently proposed object algebras are evaluated against these criteria. It is shown that there exists no object algebra that satisfies all the criteria. It is argued that... View full abstract»

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  • A rule-based query rewriter in an extensible DBMS

    Publication Year: 1991, Page(s):248 - 256
    Cited by:  Papers (1)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (776 KB)

    An integrated approach to query rewriting in an extensible database server supporting ADTs, objects, deductive capabilities and integrity constraints is described. The approach is extensible through a uniform high level rule language used by the database implementor to specify optimization techniques. This rule language is compiled to enrich the strategy component and the knowledge base of the rew... View full abstract»

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