摘要：Probabilistic XML tree is a typical probabilistic XML data model for representing uncertainty in the form of probability which can be described the nested probabilistic XML element unit. The path set in probabilistic XML unit tree can be analyzed through parsing it and drawing out the corresponding probabilistic XML unit schema tree. The node probability and the node probability threshold computation are defined first. Then the set operations are defined. The probabilistic XML XQuery sentences are extended to query a node or nodes probability, path probability and to list the possible world set. The instance analysis shows that probabilistic XML data is an effective method representing probability data and the given basic operation can realize the related probability query.
关键词：probabilistic XML element unit;probabilistic XML data tree;probabilistic XML element tree;query;basic operation
