Recent years have seen the development of a number of expert system type tools who's primary objective is to provide support to a human during the process of database analysis and design. It is generally accepted ...
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Design of distributed object-oriented databases inherits the design problems from the relational distributed databases and presents additional difficulties related to schema represented by classes and their possible c...
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This paper proposes a simple and powerful approach to associating rules with events in reactive object-oriented database systems. In it we propose a new run time subscription mechanism, which associates rules with spe...
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The authors present a secure kernelized architecture for multilevel object-oriented database management systems. The architecture is based on the notion of a message filter. It builds upon the typical architecture of ...
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This paper describes the effect of schema evolution operations on the implementation of methods. The effect of these operations is captured as temporary inconsistencies. Extensions for handling these temporary inconsi...
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In this paper, an analysis of the schema evolution process in objectorienteddatabases is made using an objectoriented data model that supports temporal features and versions definition - the Temporal Versions Model...
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This paper presents a Data Definition Language (DDL), called TQ L, based on an object-oriented data model characterized by the possibility of expressing integrity constraints in the schema of the database. This work o...
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Clustering is an effective mechanism for retrieving complex objects. Many object-oriented database management systems have suggested variant clustering schemes to improve their performance. Two issues may compromise t...
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Automatically managing the evolutionary histories of both schema and data is an attractive feature for temporal object-oriented database management systems (OODBMS). It can make the temporal OODBMSs more suitable for ...
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Although object-oriented database systems offer more powerful modeling capability than relational database systems, their performance suffers from the increased complexity in the data model. Recently, a lot of researc...
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ISBN:
(纸本)0889863237
Although object-oriented database systems offer more powerful modeling capability than relational database systems, their performance suffers from the increased complexity in the data model. Recently, a lot of research has been directed to mitigating this problem by building indexes over single classes, class hierarchies or nested object hierarchies. In this paper, we propose a new indexing method. It is based on the technique of signature files, but differs from the existing methods in two aspects: (1) all the signature files are organized into a hierarchy to filter irrelevant data as early as possible;(2) a signature file itself is stored as a tree structure (called a signature tree) to speed up the signature scanning. Together with the concept of query signature hierarchies, this technique reduces the search space dramatically and therefore improves significantly the time complexity of query evaluation.
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