The Deep Web is constituted by data accessible through web pages, but not readily indexable by search engines, as they are returned in dynamic pages. In this paper we propose a framework for accessing Deep Web sources, represented as relational tables with so-called access limitations, with keyword-based queries. We formalize the notion of optimal answer and investigate methods for query processing. We also outline the main ideas of our implementation of a prototype system for Deep Web keyword search.
['Andrea Calì', 'Thomas W. Lynch', 'Davide Martinenghi', 'Riccardo Torlone']
Processing Keyword Queries Under Access Limitations