Demonstrating ProApproX 2.0
Asma Souihli, Pierre Senellart · 2012
ProApproX 2.0 allows users to query uncertain tree-structured data in the form of probabilistic XML documents. The demonstrated version integrates a fully redesigned query engine that, first, produces a propositional formula that represents the probabilistic lineage of a given answer over the probabilistic XML document, and, second, searches for an optimal strategy to approximate the probability of the lineage. This latter part relies on a query-optimizer-like approach: exploring different evaluation plans for different parts of the formula and predicting the cost of each plan, using a cost model for the various evaluation algorithms. The demonstration presents the graphical user interface of ProApproX 2.0, that allows a user to input an XPath query and approximation parameters, and lists query results with their probabilities; the interface also gives insight into the way the computation is performed, by displaying the compilation of the query lineage as a tree annotated with evaluation operators.