Management of large quantities of complex data is essential in many advanced application areas object-oriented (OO) database management system have been developed to effectively model and process the complex domain kn...
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Management of large quantities of complex data is essential in many advanced application areas object-oriented (OO) database management system have been developed to effectively model and process the complex domain knowledge. They have been shown to outperform sam existing relational systems. The existing implementations of OO database management system attempt to improve the efficiency of OO queries by explicitly capturing the relationships among objects. However, the execution of complex queries involving the retrieval of objects from many classes and relationships among them causes the existing system to operate inefficiently. In this paper, we present parallel algorithms for the processing of queries against a large OO database The algorithms are based on a closed model of query processing using pattern-based access instead of the conventional value-based access. During processing, the algorithms avoid the execution of time-consuming join operations by making use of the explicitly stared object associations. Generation of large quantities of temporary data is avoided by marking objects using their identifiers and by employing a two-phase query processing strategy, A query is processed by concurrent multiple waves, thereby improving parallelism and avoiding the complexities introduced in their sequential implementation. The correctness and the performance of the parallel algorithms have been tested and analyzed by running parallel programs on a 32-node Transputer based parallel machine designed and developed at the IBM Research Center at Yorktown Heights, New York Benchmark queries of different semantic complexities are generated, and their performance is analyzed for various data and query parameters.
This article presents a framework developed for accommodating various object migrations in 'statically-typed' objectdatabases. Requirements for supporting object migrations are stipulated, and a conceptual mo...
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This article presents a framework developed for accommodating various object migrations in 'statically-typed' objectdatabases. Requirements for supporting object migrations are stipulated, and a conceptual model for describing and facilitating different kinds of migrations is described. Associated issues of controlling such migrations are then addressed, along with an initial investigation on the inference of implied migration paths and the completeness of migration operators. Some guidelines are then given to help users conduct migrations more effectively. An implementation prototype on top of an object-oriented database system was built, which embodies full support of all migration types specified in the migration model.
XML has become the standard for publishing and exchanging data on the Web. Since most of the business data nowadays are stored in structured databases including relational and object-oriented databases (OODB), it is o...
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XML has become the standard for publishing and exchanging data on the Web. Since most of the business data nowadays are stored in structured databases including relational and object-oriented databases (OODB), it is of significance to automate the transformation process and generate the XML data containing information from existing databases. At the same time, information imprecision and uncertainty exist in many practical applications, and for this reason, fuzzy data modeling has been extensively investigated in various data models. As such, there is an increasing need to effectively publish fuzzy structured data as fuzzy XML documents for Web-based applications. In this paper, we take a significant step in a fundamental consolidation of fuzzy XML. In particular, we are interested in finding an XML schema that best describes the existing fuzzy object-oriented schema. To accomplish this, we first offer mapping formalisms to capture the semantics of fuzzy XML Schema and fuzzy object-oriented schema. To allow for better and platform independent sharing of data stored in an object-oriented format, we investigate the formal transformation from fuzzy OODB to fuzzy XML and develop a set of rules to assist in the transformation process.
The paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational ...
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The paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational view of data modelling not only in its functionality but also in the techniques employed in its construction and use. Under this assumption, the kinds of issues that have to be tackled for a similar research strategy to produce comparable results are highlighted. The authors motivate their terms of comparison, characterize three broad approaches to deductive object-oriented databases and introduce the notion of language convergence to help in the characterization of some shortcomings that have been perceived in them. Three proposals that have come to light in the past three years are looked into in some detail, in so far as they exemplify some of the positions in the space of choices defined. The main contribution of the paper is towards a characterization of the language convergence property of deductive database languages which has a key role in addressing critiques of the deductive and object-oriented database research enterprise. A basic familiarity with notions from deductive databases and from object-oriented databases is assumed.
Conventional object-oriented database (OODB) systems follow a class-based approach to model real world entities and their relationships, which imposes several difficulties when more advanced "dynamic functions&qu...
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Conventional object-oriented database (OODB) systems follow a class-based approach to model real world entities and their relationships, which imposes several difficulties when more advanced "dynamic functions" are needed by the applications. One of such dynamic functions is conceptual clustering - the ability to dynamically group a set of existing objects together as a higher-level abstract object (called a "cluster"). The conceptual clustering model (CCM) that we have defined is an extension to current object-oriented models, which facilitates the modeling of dynamic, evolving, and/or ad hoc object clusters through a well-devised clustering mechanism that incorporates "roles". This paper presents the advanced features of CCM, along with its associated query language facilities devised for supporting general definition and access of clusters (and roles). An experimental prototype of the CCM has been constructed on top of a persistent object storage manager, running on a Sun4 workstation.
The Resource Description Framework and RDF Schema recommended by the World Wide Web Consortium provide a flexible model for semantically representing information about resources on the Web, which are playing an increa...
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The Resource Description Framework and RDF Schema recommended by the World Wide Web Consortium provide a flexible model for semantically representing information about resources on the Web, which are playing an increasingly important role in intelligent processing of large-scale data. With the widespread acceptance and applications of RDF(S), construction of RDF(S) is of increasing importance. Automatic construction of RDF(S) with diverse data has attracted more attention. In this paper, we propose a novel approach for constructing an RDF(S) with object-oriented databases that are suitable for non-traditional applications. We propose the formal rules of mapping an object-oriented database model into a RDF(S) model based on the formal definitions of these two models. We develop a tool named OODB2RDF to verify our approach.
The problem of access differentiation in generic object-oriented databases is investigated. Aspects of data processing and access control in databases are considered.
The problem of access differentiation in generic object-oriented databases is investigated. Aspects of data processing and access control in databases are considered.
We present a theorem-prover based analysis tool for object-oriented database systems with integrity constraints. object-oriented database specifications are mapped to higher-order logic (HOL). This allows us to reason...
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ISBN:
(纸本)3540657037
We present a theorem-prover based analysis tool for object-oriented database systems with integrity constraints. object-oriented database specifications are mapped to higher-order logic (HOL). This allows us to reason about the semantics of database operations using a mechanical theorem prover such as Isabelle or PVS. The tool can be used to verify various semantics requirements of the schema (such as transaction safety, compensation, and commutativity) to support the advanced transaction models used in workflow and cooperative work. We give an example of method safety analysis for the generic structure editing operations of a cooperative authoring system.
This paper deals with modelling constraints in object-oriented databases, with emphasis given on exceptions. Constraints are restrictions on properties and relations of database objects that ensure the integrity of da...
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ISBN:
(纸本)3540587861
This paper deals with modelling constraints in object-oriented databases, with emphasis given on exceptions. Constraints are restrictions on properties and relations of database objects that ensure the integrity of data. Therefore, they should be obeyed by every object, but as in real-life, there are some exceptions to this ruler object-oriented databases provide rich semantic constructs, adequate to model real-world relations. Inheritance of constraints in object-oriented databases has been treated in a completely mandatory way, providing no room for exceptions. In this paper, an object-oriented constraint representation scheme is presented, along with a methodology for modelling constraint exceptions. Finally, an algorithm is described that ensures correct runtime resolution of constraint applicability. Since business is not in abstract, but in real-world, business database modelling would be greatly benefited from a tool that allows both a clear definition and an efficient enforcement of constraints with exceptions.
In this paper a semantic approach for the specification and the management of databases with evolving schemata is introduced. It is shown how a general object-oriented model for schema versioning and evolution can be ...
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ISBN:
(数字)9783540449577
ISBN:
(纸本)3540677976
In this paper a semantic approach for the specification and the management of databases with evolving schemata is introduced. It is shown how a general object-oriented model for schema versioning and evolution can be formalized;how the semantics of schema change operations can be defined;how interesting reasoning tasks can be supported, based on an encoding in description logics.
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