Abstract
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 values or probabilistic partial values into a set of relations containing only definite values. Bipartite graph matching techniques are then applied to develop efficient algorithms for the extended division that handles partial values. The refinement of the maybe result is also dicussed. Finally, we study the extended division which handles probabilistic partial values.