Keyword Search in the Deep Web

TL;DR

This paper introduces a framework for effectively answering keyword queries on the Deep Web by formalizing optimal answers, identifying answerable queries, and minimizing data source accesses through query planning.

Contribution

It presents a novel formal framework and a query processing method that reduces data source accesses for keyword searches in the Deep Web.

Findings

Formalized the notion of optimal answer

Characterized answerable queries in Deep Web sources

Developed a query plan minimizing data source accesses

Abstract

The Deep Web is constituted by data that are accessible through Web pages, but not readily indexable by search engines as they are returned in dynamic pages. In this paper we propose a conceptual framework for answering keyword queries on Deep Web sources represented as relational tables with so-called access limitations. We formalize the notion of optimal answer, characterize queries for which an answer can be found, and present a method for query processing based on the construction of a query plan that minimizes the accesses to the data sources.