Description-driven systems based on meta-objects are an increasingly popular way to handle complexity in large-scale object- oriented database applications. Such systems facilitate the management of large amounts of d...
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In this paper, we propose a schema versioning mechanism to manage the schema evolution in temporal object-oriented databases. The schema evolution management uses an object-oriented data model that supports temporal f...
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Structuration, annotation and composition are amidst the most crucial modeling issues that video editing and querying in the context of a database entail. In this paper, we propose a sequence-based, object-oriented da...
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Structuration, annotation and composition are amidst the most crucial modeling issues that video editing and querying in the context of a database entail. In this paper, we propose a sequence-based, object-oriented data model that addresses them in an unified, yet orthogonal way. Thanks to this orthogonality, the interactions between these three aspects are properly captured, i.e., annotations may be attached to any level of video structuration, and all the composition operators preserve the structurations and annotations of the argument videos. We also propose to query both the structuration and the annotations of videos using an extension of ODMG's OQL which integrates a set of algebraic operators on sequences. The overall proposal is formalized and implemented on top of an object-oriented DBMS.
Mobiscope is a discovery service where clients submit longrunning queries to continually find sets of moving network resources within a specified area. As in moving objectdatabases (MODBMSs), moving resources adverti...
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Moving objectdatabases have received considerable attention recently. Previous work has concentrated mainly on modeling and indexing problems, as well as query selectivity estimation. Here we introduce a novel proble...
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Classical data models like the relational data models have proven to have limitations in modeling spatial data in many aspects. In the latest computer technology, object-oriented database technology extends support fo...
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In this paper, we present our Form-driven approach for reverse engineering of relationa databases. This methodology uses the information extracted from both form structure and instances as a database reverse engineeri...
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In this paper, we present our Form-driven approach for reverse engineering of relationa databases. This methodology uses the information extracted from both form structure and instances as a database reverse engineering input using an interaction with a user. Through a combination of forms structures and data instances analysis, forms relational sub-schemas and their constraints are derived. These relational sub-schemas are mapped to object sub-schemas, which will be merging into global object-oriented schema that presents the whole underlying databases. The resulting global object-oriented schema must be validated as a rich and correct representation of the application domain.
The design of the new model for the full transformation of the spatial data from relational database to object-oriented database is performed in objectoriented environment using the object-oriented analysis and desig...
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In previous work, we have modeled a vocabulary given as a semantic network by an object-oriented database (OODB). The OODB schema thus obtained provides a compact abstract view of the vocabulary. This enables the fast...
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In previous work, we have modeled a vocabulary given as a semantic network by an object-oriented database (OODB). The OODB schema thus obtained provides a compact abstract view of the vocabulary. This enables the fast traversal of the vocabulary by a user. In the semantic network vocabulary, the IS-A relationships express the specialization hierarchy. In our OODB modeling of the vocabulary, the SUBCLASS relationship expresses the specialization hierarchy of the classes and supports the inheritance of their properties. A typical IS-A path in the vocabulary has a corresponding shorter SUBCLASS path in the OODB schema. In this paper we expose several cases where the SUBCLASS hierarchy fails to fully correspond to the IS-A hierarchy of the vocabulary. In these cases there exist traversal paths in the semantic network for which there are no corresponding traversal paths in the OODB schema. The reason for this failure is the existence of some IS-A relationships between concepts of two classes, which are not connected by a SUBCLASS relationship. This phenomenon weakens the accuracy of our modeling. To rectify the situation we introduce a new OODB semantic relationship IS-A' to represent the existence of IS-A relationships between concepts of a pair of classes which are not connected via a SUBCLASS relationship. The resulting schema contains both SUBCLASS relationships and IS-A' relationships which completely model the IS-A hierarchy of the vocabulary. We define a mixed-class level traversal path to contain either SUBCLASS or IS-A' relationships. Consequently, each traversal path in the semantic network has a corresponding mixed traversal path in the OODB schema. Hence the introduction of the semantic OODB IS-A' relationship improves the modeling of semantic network vocabularies by OODBs. Copyright (C) 2003 John Wiley Sons, Ltd.
An object-oriented database (OODB) has been becoming more important in recent years. It can deal with a large amount of complex objects and relationships that relational database (RDB) systems cannot handle well. Howe...
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An object-oriented database (OODB) has been becoming more important in recent years. It can deal with a large amount of complex objects and relationships that relational database (RDB) systems cannot handle well. However, the retrieval and update performance of an OODB depends on indexing techniques. In this paper, we study the indexing techniques on OODBs, based on an inheritance hierarchy and an aggregation hierarchy. Given the access probability and the size of each class, we propose a cost function to evaluate the gain of building an index on an inheritance hierarchy. For an aggregation hierarchy, we use a path-catenation technique to evaluate how to build index files on classes, Through some experiments, we found our methods have better retrieval performance than most ones proposed before. (C) 2000 Elsevier Science Inc. All rights reserved.
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