Database Reference
In-Depth Information
Chapter 2
Practical Approaches to the
Many-Answer Problem
Mounir Bechchi
LINA-University of Nantes, France
Guillaume Raschia
LINA-University of Nantes, France
Noureddine Mouaddib
LINA-University of Nantes, Morocco
ABSTRACT
Database systems are increasingly used for interactive and exploratory data retrieval. In such retriev-
als, users' queries often result in too many answers, so users waste significant time and efforts sifting
and sorting through these answers to find the relevant ones. This chapter first reviews and discusses
several research efforts that have attempted to provide users with effective and efficient ways to access
databases. Then, it focuses on a simple but useful strategy for retrieving relevant answers accurately
and quickly without being distracted by irrelevant ones. Generally speaking, the chapter presents a very
recent but promising approach to quickly provide users with structured and approximate representations
of their query results, a must have for decision support systems. The underlying algorithm operates on
pre-computed knowledge-based summaries of the queried data, instead of raw data themselves. Thus,
this first-citizen data structure is also presented in this chapter.
1. INTRODUCTION
With the rapid development of the World Wide Web, more and more accessible databases are available
online; A July 2000 study (Bergman, 2001) estimated 96000 relational databases were online and the
number increased by seven times in 2004 (Chang, He, Li, Patel & Zhang, 2004). The increased vis-
ibility of these structured data repositories made them accessible to a large number of lay users, typi-
cally lacking a clear view of their content, moreover, not even having a particular item in mind. Rather,
