Whan-Kyu Whang

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The need for accessing independently developed database management systems using a unified conceptual view has been well recognized. View or schema integration is an important component of this problem of designing heterogeneous or federated database management systems. In the proposed approach, we assume that relations that are known to be interrelated are(More)
In this paper, estimation using we discuss the errors in selectivity the multilevel multidimensional file structure. We rst analyze the cause P rid file(MLGF), a of the estimation errors, and then investigate five factors affecting the accuracy of estimation: (1) the data distrzbution in a region, (2) the number of records stored in the MLGF, (3) the page(More)
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