Implementing the Division Operation on a Database containing Uncertain Data

Uncertain data in databases were originally denoted as null values which were later generalized to partial values Based on the concept of partial values we have further generalized the notion to probabilistic partial values In this paper an important operation division is fully studied to handle partial values and probabilistic partial values Due to the uncertainty of partial values and probabilistic partial values the corresponding extended division may produce maybe tuples and maybe tuples with degrees of uncertainty respectively To process this extended division we decompose a relation consisting of partial val ues or probabilistic partial values into a set of relations containing only de nite values Bipartite graph matching techniques are then applied to develop e cient algorithms for the extended division that handles partial values The re nement on the maybe result is also discussed Finally we study the extended division that handles probabilistic partial values keywords partial values probabilistic partial values graph matching uncertain data To whom all correspondence should be sent