The chase has long been used as a central tool to analyze dependencies and their effect on queries. It has been applied to different relevant problems in database theory such as query optimization, query containment and equivalence, dependency implication, and database schema design. Recent years have seen a renewed interest in the chase as an important tool in several database applications, such as data exchange and integration, query answering in incomplete data, and many others. It is well known that the chase algorithm might be non-terminating and thus, in order for it to find practical applicability, it is crucial to identify cases where its termination is guaranteed. Another important aspect to consider when dealing with the chase is that it can introduce null values into the database, thereby leading to incomplete data. Thus, in several scenarios where the chase is used the problem of dealing with data dependencies and incomplete data arises. This book discusses fundamental issues concerning data dependencies and incomplete data with a particular focus on the chase and its applications in different database areas. We report recent results about the crucial issue of identifying conditions that guarantee the chase termination. Different database applications where the chase is a central tool are discussed with particular attention devoted to query answering in the presence of data dependencies and database schema design. Table of Contents: Introduction / Relational Databases / Incomplete Databases / The Chase Algorithm / Chase Termination / Data Dependencies and Normal Forms / Universal Repairs / Chase and Database Applications

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Sergio Greco is a full professor and chair of the Department of Electronics, Computer and System Science at the University of Calabria (Italy). He was an assistant professor (1988-1998) and associate professor (1998-2000) at the University of Calabria, as well as a visiting researcher at the Microelectronics and Computer Corporation of Austin (1990-1991) and at the of University of California at Los Angeles (1996, and again in 1998). Currently he is an Associate Editor of the IEEE Transaction of Knowledge and Data Engineering Journal. Professor Greco's research interests include database theory, data integration, inconsistent data, data mining, knowledge representation,logic programming, and computational logic. Cristian Molinaro received a Ph.D. degree in Computer Science Engineering from the University of Calabria, Italy. He was a Visiting Scholar at the Department of Computer Science and Engineering of the State University of New York at Buffalo. From 2009-2011, he was a Faculty Research Assistant at the University of Maryland Institute for Advanced Computer Studies. Currently, he is an Assistant Professor at the University of Calabria, Italy. His research interests include inconsistency and incompleteness management, logic programming, and social network analysis. Francesca Spezzano received a Ph.D. in Computer Science Engineering from the University of Calabria, Italy in 2012. She was a Visiting Scholar at the Computer Science Department (Database Group) of the University of California at Santa Cruz from October 2010-July 2011. Currently, she is a Post-Doc Researcher at the University of Calabria, Italy. Her research interests include dataexchange, inconsistent databases, and logic programming.