This article proposes a core query algebra for probabilistic databases. In essence, this core is part of the query languages of most probabilistic database systems proposed so far...
The important challenge of evaluating XPath queries over XML streams has sparked much interest in the past few years. A number of algorithms have been proposed, supporting wider f...
We present a formal framework for capturing the provenance of data appearing in XQuery views of XML. Building on previous work on relations and their (positive) query languages, w...
Recursion represents an important addition to the SQL language. This work focuses on the optimization of linear requeries in SQL. To provide an abstract framework for discussion, ...
This paper describes the architecture of a Bulgarian–Bulgarian question answering system — BulQA. The system relies on a partially parsed corpus for answer extraction. The que...