W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of Multiple Autonomous Databases. ACM Computing Surveys, 22(3):267-293, 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....in a given organization can be very large; on the other hand a particular application is most likely to use only a small subset of these databases. Multidatabase or federated database systems provide for the interoperability of autonomous database systems without requiring their global integration [MH80, LMR90, SL90, SC94, PS95]. In order to answer queries in multidatabase systems three distinct processes need to be performed by the user, database administrator, and or system as shown in Figure 1. The Schema Integration includes a possible schema transformation step, followed by correspondence identification, and an ....

W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 33:267--293, 1990.

....have key attributes and if these attributes are not expensive themselves. Very few query processing systems take into account source capabilities. Conventional systems such as System R [61] Ingres [67] DB2 [22] and NonStop SQL [63] assume homogeneous source capabilities. Multidatabase systems [45, 48, 64] address heterogeneity and autonomy, but still assume that simple selection queries are supported by all sources. A few new systems like the Information Manifold [40, 41] Garlic [28, 55] and DISCO [35, 72] have directly addressed source capabilities. In the Information Manifold, one can only ....

.... Optimizers The expansion of the Web has led to mediator prototypes that combine information from multiple heterogeneous sources [4, 9, 13, 18, 28, 37, 68, 71] Similarly, prototypes for integrating databases have been developed, and recently integration products are being released or announced [2, 5, 7, 26, 45]. We note that there is a close connection between mediator based systems [79] and distributed database systems [53] Many mediator systems have borrowed techniques for query optimization from the world of distributed databases. There has been a great deal of published work on these techniques ....

W. Litwin, L. Mark, N. Rossopoulos. Interoperability of Multiple Autonomous Databases. In ACM Computing Surveys, Vol. 22, No. 3, 267-293.

....This is a crucial point and intro duces a high degree of innovation into the traditional distributed databases and multi database systems data management approach. The common assumption in this area is, in fact, to have a global database schema, usually obtained by skilled databases designers [13, 9]. In the new dynamic setting of P2P, we cannot assume the existence of a global schema for all databases in a P2P network or even those of the acquianted databases. Nevertheless, as proposed both in [4] and in this paper, the architecture of heterogeneous distributed databases or of ten called ....

W.Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(3):267-293, 1990.

....reports or news articles) The idea of mediating between different databases using local semantic relationships is not new. Federated databases and cooperative databases have used the notion of inter schema dependencies to define semantic relationships between databases in a federation (e.g. [32]) However, they assumed that each database in the federation stored data, and hence the focus was on mapping between the stored relations in the federation. Our emphasis is on supporting schema mediation among large numbers of peers, so we need to be able to map both relationships among stored ....

W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys,22 (3):267--293, 1990.

....or even those of all acquainted databases. Moreover, peers should be able to establish and evolve acquaintances, preferably with little human intervention. Thus, we need to avoid protracted tasks by skilled database designers and DBAs required by traditional distributed and multi database systems [15, 1]. In [2] we # ITC IRST, 38050 Povo, Trento, Italy University of Trento, 38050 Povo, Trento, Italy University of Toronto M5S 3H5, Toronto, Ontario, Canada Microsoft Corporation, One Microsoft Way, Redmond, WA 98052 6399 introduce the intuitions underlying our proposed data management ....

W. Litwin, L. Mark, and N. Roussapoulos. Interoperability of multiple autonomous databases. ACM Computing Survey, 22(1):267--293, 1990.

....network, or even those of all acquainted databases. Moreover, this setting implies that peers should be able to integrate with little human intervention. Thus, we need to avoid protracted tasks by skilled database designers and DBAs required by traditional distributed and multi database systems [9,10]. This paper introduces the Local Relational Model (LRM) as a data model specifically designed for P2P applications. LRM assumes that the set of all data in a P2P network consists of local (relational) databases, each with a set of acquaintances, which define the P2P network topology. For each ....

W. Litwin, L. Mark, N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys 22:3 (1990), 267-293.

....and conceptualizations employed by the various information providers and consumers. Providing access to heterogeneous and distributed databases through integrated views has been studied from the early 80 s [6] A large number of papers exist on the integration of distributed databases and [36,46,43] are comprehensive studies on the topic. However such approaches for data This work was partially supported by the European project C Web (IST1999 13479) The work of this author was supported by a fellowship from the TMR European Network Chrorochronos. integration are not appropriate ....

W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(1):267--293, March 1990.

....[ 2; 10 ] A federated database management system (FDBMS) which is responsable of the management of the federation must be able to cope with all these problems. The key component of a FDBMS, where these problems are faced at a conceptual level, is the conceptual multi database level (CML) [ 11 ] . The CML is composed of the conceptual schema (CS) of the DBs of the federation and a distributes schema (DS) representing how the DBs integrate. The definition of a formal semantics for the CML able to represent and solve these problems is a key point to understand, specify and verify the ....

W. Litwin, L. Mark, and N. Roussapoulos. Interoperability of multiple autonomous databases. ACM Computing Survey, 22(1):267--293, 1990. 18

....for e ectively answering queries posed to the data integration system in this case. 1 Introduction Integrating heterogeneous data sources is a fundamental problem in databases, which has been studied extensively in the last two decades both from a formal and from a practical point of view [3, 29, 30, 25, 10, 20]. Recently, mostly driven by the need to integrate data sources on the Web, much of the research on integration has focussed on so called data integration [19, 31, 20] Data integration is the problem of combining the data residing at di erent sources, and providing the user with a uni ed view of ....

Witold Litwin, Leo Mark, and Nick Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(3):267-293, 1990.

....section we introduce a model for the representation of data together with an explicit description of their underlying interpretation context. This model, which we call Metadata based Integration model for data X change, or MIX for short, can be seen as a self describing data model in the sense of [MR90, LMR90]. This is because information about the structure and semantics of the data is not provided as a separately specified data schema, but is given as part of the available data itself. Thus, MIX allows a flexible association of context information in the form of metadata on an extensional level, and ....

Litwin, W; Mark, L.; Roussopoulos, N.: Interoperability of Multiple Autonomous Databases, In: ACM Computing Surveys, Vol.22, No.3, Sep. 1990

....and institution, in the previous chapter example. These semantic equivalent paths must be identified and kept as part of the mapping information. Observer keeps relationships among independent ontologies, relating conceptual schemas each other in an approach close to multidatabase systems [Lit90] or loosely coupled federated database systems [She90] The thesis approach goes in a different direction, working with a global conceptual schema in an architecture similar to the wrapper mediator architecture presented in the figure 2.6. 5.2 Mapping of XML Query Statements The thesis approach ....

LITWIN, W.; MARK, L.; ROUSSOPOULOS, N. Interoperability of Multiple Autonomous Databases. ACM Computing Surveys, v.22, n.3, Set 1990, p.267-293.

....use is also proposed. Index Terms Query processing, textual database, information retrieval, join algorithm, multidatabase. ###p### 1INTRODUCTION ESEARCHES in multidatabase system have been intensified in recent years [4] 5] [9], 13] 12] 16] 19] In this paper, we consider a multidatabase system that contains both local systems that manage structured data (e.g. relational DBSs) and local systems that manage unstructured data (e.g. information retrieval (IR) systems for handling text) The global schema of a ....

# W. Litwin, L. Mark, and N. Roussopoulis, "Interoperability of Multiple Autonomous Databases," ACM Computing Surveys, vol. 22, no. 3, pp. 267-293, Sept. 1990.

....and how the data is retrieved. How to process such a global query efficiently is the task of global query optimization. Research supported by the US National Science Foundation under Grant # IIS 9811980 and The University of Michigan under OVPR and UMD grants. A major challenge, among others [4, 7, 8, 9, 14], for global query optimization in an MDBS is that some necessary local information, such as local cost models, may not be available at the global level due to local autonomy preserved in the system. However, the global query optimizer needs such information to decide how to decompose a global ....

W. Litwin, et al. Interoperability of multiple autonomous databases. ACM Comp. Surveys, 22(3):267--293, 1990.

....individual DBSs retain to serve existing applications [2] Briefly speaking, local autonomy refers to the situation where each component DBS retains complete control over its local data and operations. The term MDBS has been used by different people to mean different things [20] Litwin et al. [11] use it to mean a system managing multiple databases without a global schema. The essential component of such an MDBS is a language used to manage interoperable databases. Local database systems are loosely coupled. Local autonomy is fully supported. Dayal and Hwang [6] Breitbart and Silberschatz ....

W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(3):267--293, Sept. 1990.

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W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of Multiple Autonomous Databases. ACM Computing Surveys, 22(3):267-293, 1990.

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Litwin, W; Mark, L.; Roussopoulos, N.: Interoperability of Multiple Autonomous Databases, In: ACM Computing Surveys, Vol.22, No.3, Sep. 1990

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W. Litwin, L. Mark, and Nick Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(3):267-293, 1990.

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W. Litwin, L. Mark, and N. Roussopoulos, "Interoperability of multiple autonomous databases," ACM Computing Surveys, vol. 22 (3), pp. 267--293, 1990.

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Litwin, W., Mark, L., and Roussopoulos, N., "Interoperability of Multiple Autonomous Databases," ACM Computing Surveys, Vol.22, No. 3, September, 1990.

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W. Litwin, L. Mark, N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys 22:3 (1990), 267-293.

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W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22 (3):267--293, 1990.

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Litwin, W., Mark, L., Roussopoulos, N.: Interoperability of multiple autonomous databases. ACM Computing Surveys 22 (1990) 267--293

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W. Litwin, L. Mark, and N. Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 23:267--293, 1990.

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W. Litwin, L. Mark & N. Roussopoulos, "Interoperability of Multiple Autonomous Databases", ACM Computing Surveys, 22(3), September 1990, 267-293.

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Witold Litwin, Leo Mark, and Nick Roussopoulos. Interoperability of multiple autonomous databases. ACM Computing Surveys, 22(3), September 1990.

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