Optimization of Queries over Interval Probabilistic Data
SUM '08 Proceedings of the 2nd international conference on Scalable Uncertainty Management
Towards Relational Schema Uncertainty
SUM '09 Proceedings of the 3rd International Conference on Scalable Uncertainty Management
A Survey on Uncertainty Management in Data Integration
Journal of Data and Information Quality (JDIQ)
| Hi-index | 0.00 |
In this paper we present a data model for uncertain data, where uncertainty is represented using interval probabilities. The theory introduced in the paper can be applied to different specific data models, because the entire approach has been developed independently of the kind of manipulated objects, like XML documents, relational tuples, or other data types. As a consequence, our theory can be used to extend existing data models with the management of uncertainty. In particular, the data model we obtain as an application to XML data is the first proposal that combines XML, interval probabilities and a powerful query algebra with selection, projection, and cross product. The cross product operator is not based on assumptions of independence between XML trees from different collections. Being defined with a possible worlds semantics, our operators are proper extensions of their traditional counterparts, and reduce to them when there is no uncertainty. The main practical result of the paper is a set of equivalences that can be used to compare or rewrite algebraic queries on interval probabilistic data, in particular XML and relational.