Database integration in a distributed heterogeneous database system

Abstract. This research investigates an approach to query processing in a multidatabase system that uses an objectoriented model to capture the semantics of other data models. The object-oriented model is used to construct a global schema, defining an integrated view of the different schemas in the environment. The model is also used as a self-describing model to build a meta-database for storing information about the global schema. A unique aspect of this work is that the object-oriented model is used to describe the different data models of the multidatabase environment, thereby extending the meta database with semantic information about the local schemas. With the global and local schemas all represented in an object-oriented form, structural mappings between the global schema and each local schema are then easily supported. An object algebra then provides a query language for expressing global queries, using the structural mappings to translate object algebra queries into SQL queries over local relational schema. The advantage of using an object algebra is that the object-oriented database can be viewed as a blackboard for temporary storage of local data and for establishing relationships between different databases. The object algebra can be used to directly retrieve temporarily-stored data from the object-oriented database or to transparently retrieve data from local sources using the translation process described in this paper.

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“…The ER and EER models were used in ADDS [4], OMNIBASE [19], and SCOOP [24]. Both models have been weak, however, in deriving external views.…”

Section: Related Workmentioning

confidence: 99%

Object-oriented query language access to relational databases: A semantic framework for query translation

Urban

Abdellatif

1995

Journal of Systems Integration

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“…The line of work includes a breakdown of schematic heterogeneities into domain incompatibilities, entity definition incompatibilities, data value incompatibilities, abstraction level incompatibilities, and schematic discrepancies, each of which is further broken down into different kinds of conflicts. Different taxonomies of schematic heterogeneities and resolution methods appear in many other works about schema integration and federated, distributed, heterogeneous, and multi-database systems ( [4], [25] and others).…”

Section: Schema Integrationmentioning

confidence: 99%

“…Semantic models 4 are conceptual models that formally define the meaning of the objects and information units, in terms of fundamental notions, properties and behaviors. Semantic models define the meanings of the terms used, by reference to taxonomies, thesauri, formal dictionaries or axiomatic characterizations.…”

Section: Information Domainmentioning

confidence: 99%

Concepts for automating systems integration

Barkmeyer¹,

Feeney²,

Denno³

et al. 2003

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“…As we will see in the following algorithm (for substi-production), such informations can be obtained by doing a simple analysis of the algebra expression to be translated (see lines [2][3][4][5]. In the algorithm, the following definitions are used:…”

Section: Translation Of Simple Algebra Expressions: P P P P P(s S S Smentioning

confidence: 99%

“…for each y OE {car 1 ', ..., car m '} do {p time (s price>10000 (y))} so that it can be evaluated in DB 3 .…”

Section: Local Query Translationmentioning

confidence: 99%

Query evaluation for distributed heterogeneous relational databases

Chen

Benn²

1998

Proceedings 3rd IFCIS International Conference on Cooperative Information Systems (Cat No 98EX122) COOPIS-98

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In this article, we consider the query evaluation problem in relational multidatabases and develop a method for generating optimal plans for queries submitted to such a system. Three aspects will be discussed: query transformation, join tree balance and node allocation. For query translation, the concept of relation structure terms (RST) is introduced. Based on RSTs, we can transform a query into another form automatically by constructing derivation rules for them. Further, we extend the approach for balancing a join tree proposed by Du et al. so that more balanced join trees can be obtained. Lastly, we present the concept of dynamic time tables for performing node allocation in a dynamic programming manner.

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Database integration in a distributed heterogeneous database system

Cited by 90 publications

References 1 publication

Object-oriented query language access to relational databases: A semantic framework for query translation

Object-oriented query language access to relational databases: A semantic framework for query translation

Concepts for automating systems integration

Query evaluation for distributed heterogeneous relational databases

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