Journal of East China Normal University(Natural Sc

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Two new Top-k queries in uncertain database

QIU Xin, LIN Xin   

  1. Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University, Shanghai 200241, China
  • Received:2015-11-27 Online:2017-01-25 Published:2017-01-13


Since the pre-existing Top-k queries in uncertain databases almost are based on tuple level rather than x-tuple level restricts its application. The paper proposes two new instance-level Top-k queries and executive algorithm in uncertain databases in order to get intuitive query results. These two new queries take both  rank and confidence of each x-tuple’s tuple, figuring out the most meaningful position in the returned results. After the optimization of the executive algorithm, its executive efficiency has been improved significantly.

Key words: uncertain database, Top-k query