| dc.description.abstract |
Heterogeneity arises naturally in virtually all real-world data. This paper presents evolutionary extensions to a relational database system for supporting three classes of data het-erogeneity: variational, structural and annotational hetero-geneities. We deene these classes and show the impact of these new features on data storage, data-access mechanisms, and the data-description language. Since XML is an important source of heterogeneity, we describe how the system automatically utilizes these new features when storing XML documents. |
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