The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Dan Suciu - One of the best experts on this subject based on the ideXlab platform.
-
big data begets big Database Theory
British National Conference on Databases, 2013Co-Authors: Dan SuciuAbstract:Industry analysts describe Big Data in terms of three V's: volume, velocity, variety. The data is too big to process with current tools; it arrives too fast for optimal storage and indexing; and it is too heterogeneous to fit into a rigid schema. There is a huge pressure on Database researchers to study, explain, and solve the technical challenges in big data, but we find no inspiration in the three Vs. Volume is surely nothing new for us, streaming Databases have been extensively studied over a decade, while data integration and semistructured has studied heterogeneity from all possible angles.
-
Knowledge Compilation Meets Database Theory: Compiling Queries to Decision Diagrams
Theory of Computing Systems, 2013Co-Authors: Abhay Jha, Dan SuciuAbstract:The goal of Knowledge Compilation is to represent a Boolean expression in a format in which it can answer a range of “online-queries” in PTIME. The online-query of main interest to us is model counting, because of its application to query evaluation on probabilistic Databases, but other online-queries can be supported as well such as testing for equivalence, testing for implication, etc. In this paper we study the following problem: given a Database query q , decide whether its lineage can be compiled efficiently into a given target language. We consider four target languages, of strictly increasing expressive power (when the size of compilation is restricted to be polynomial in the data size): read-once Boolean formulae, OBDD, FBDD and d-DNNF. For each target, we study the class of Database queries that admit polynomial size representation: these queries can also be evaluated in PTIME over probabilistic Databases. When queries are restricted to conjunctive queries without self-joins, it was known that these four classes collapse to the class of hierarchical queries, which is also the class of PTIME queries over probabilistic Databases. Our main result in this paper is that, in the case of Unions of Conjunctive Queries (UCQ), these classes form a strict hierarchy. Thus, unlike conjunctive queries without self-joins, the expressive power of UCQ differs considerably with respect to these target compilation languages. Moreover, we give a complete characterization of the first two target languages, based on the query’s syntax.
-
Knowledge Compilation Meets Database Theory: Compiling Queries to Decision Diagrams
Theory of Computing Systems, 2013Co-Authors: Dan SuciuAbstract:The goal of Knowledge Compilation is to represent a Boolean expression in a format in which it can answer a range of “online-queries” in PTIME. The online-query of main interest to us is model counting, because of its application to query evaluation on probabilistic Databases, but other online-queries can be supported as well such as testing for equivalence, testing for implication, etc. In this paper we study the following problem: given a Database query q , decide whether its lineage can be compiled efficiently into a given target language. We consider four target languages, of strictly increasing expressive power (when the size of compilation is restricted to be polynomial in the data size): read-once Boolean formulae, OBDD, FBDD and d-DNNF. For each target, we study the class of Database queries that admit polynomial size representation: these queries can also be evaluated in PTIME over probabilistic Databases. When queries are restricted to conjunctive queries without self-joins, it was known that these four classes collapse to the class of hierarchical queries, which is also the class of PTIME queries over probabilistic Databases. Our main result in this paper is that, in the case of Unions of Conjunctive Queries (UCQ), these classes form a strict hierarchy. Thus, unlike conjunctive queries without self-joins, the expressive power of UCQ differs considerably with respect to these target compilation languages. Moreover, we give a complete characterization of the first two target languages, based on the query’s syntax.
-
BNCOD - Big data begets big Database Theory
Big Data, 2013Co-Authors: Dan SuciuAbstract:Industry analysts describe Big Data in terms of three V's: volume, velocity, variety. The data is too big to process with current tools; it arrives too fast for optimal storage and indexing; and it is too heterogeneous to fit into a rigid schema. There is a huge pressure on Database researchers to study, explain, and solve the technical challenges in big data, but we find no inspiration in the three Vs. Volume is surely nothing new for us, streaming Databases have been extensively studied over a decade, while data integration and semistructured has studied heterogeneity from all possible angles.
-
ICDT - Knowledge compilation meets Database Theory: compiling queries to decision diagrams
Proceedings of the 14th International Conference on Database Theory - ICDT '11, 2011Co-Authors: Abhay Jha, Dan SuciuAbstract:The goal of Knowledge Compilation is to represent a Boolean expression in a format in which it can answer a range of online-queries in PTIME. The online-query of main interest to us is model counting, because of its application to query evaluation on probabilistic Databases, but other online-queries can be supported as well such as testing for equivalence, testing for implication, etc. In this paper we study the following problem. Given a Database query q, decide whether its lineage can be compiled efficiently into a given target language. We consider four target languages, of strictly increasing expressive power(when the size of compilation is constrained to be polynomial in the input size): Read-Once Boolean formulae, OBDD, FBDD and d-DNNF. For each target, we study the class of Database queries that admit polynomial size representation: these queries can also be evaluated in PTIME over probabilistic Databases. When queries are restricted to conjunctive queries without self-joins, it was known that these four classes collapse to the class of hierarchical queries, which is also the class of PTIME queries over probabilistic Databases. Our main result in this paper is that, in the case of Unions of Conjunctive Queries (UCQ), these classes form a strict hierarchy. Thus, unlike conjunctive queries without self-joins, the expressive power of UCQ differs considerably w.r.t. these target compilation languages. Moreover, we give a complete characterization of the first two target languages, based on the query's syntax.
Antony Harfield - One of the best experts on this subject based on the ideXlab platform.
-
empirical modelling in support of constructionist learning a case study from relational Database Theory
International Conference on Advanced Learning Technologies, 2005Co-Authors: Meurig Beynon, Antony HarfieldAbstract:Conventional programming paradigms have limitations where support for constructionist learning is concerned. This paper illustrates the merits of an alternative approach to giving support for constructionist learning, based on the principles of empirical modelling (EM), with reference to an algorithm from Database Theory. Effective model-building for constructionist learning has to support activities relating to three roles: that of student, teacher and developer. This paper aims to show that EM brings far greater conceptual unity to interactions in these roles than is typically found in conventional approaches to educational software development.
-
ICALT - Empirical modelling in support of constructionist learning: a case study from relational Database Theory
Fifth IEEE International Conference on Advanced Learning Technologies (ICALT'05), 2005Co-Authors: Meurig Beynon, Antony HarfieldAbstract:Conventional programming paradigms have limitations where support for constructionist learning is concerned. This paper illustrates the merits of an alternative approach to giving support for constructionist learning, based on the principles of empirical modelling (EM), with reference to an algorithm from Database Theory. Effective model-building for constructionist learning has to support activities relating to three roles: that of student, teacher and developer. This paper aims to show that EM brings far greater conceptual unity to interactions in these roles than is typically found in conventional approaches to educational software development.
Meurig Beynon - One of the best experts on this subject based on the ideXlab platform.
-
empirical modelling in support of constructionist learning a case study from relational Database Theory
International Conference on Advanced Learning Technologies, 2005Co-Authors: Meurig Beynon, Antony HarfieldAbstract:Conventional programming paradigms have limitations where support for constructionist learning is concerned. This paper illustrates the merits of an alternative approach to giving support for constructionist learning, based on the principles of empirical modelling (EM), with reference to an algorithm from Database Theory. Effective model-building for constructionist learning has to support activities relating to three roles: that of student, teacher and developer. This paper aims to show that EM brings far greater conceptual unity to interactions in these roles than is typically found in conventional approaches to educational software development.
-
ICALT - Empirical modelling in support of constructionist learning: a case study from relational Database Theory
Fifth IEEE International Conference on Advanced Learning Technologies (ICALT'05), 2005Co-Authors: Meurig Beynon, Antony HarfieldAbstract:Conventional programming paradigms have limitations where support for constructionist learning is concerned. This paper illustrates the merits of an alternative approach to giving support for constructionist learning, based on the principles of empirical modelling (EM), with reference to an algorithm from Database Theory. Effective model-building for constructionist learning has to support activities relating to three roles: that of student, teacher and developer. This paper aims to show that EM brings far greater conceptual unity to interactions in these roles than is typically found in conventional approaches to educational software development.
Susan D Urban - One of the best experts on this subject based on the ideXlab platform.
-
Database Theory in practice learning from cooperative group projects
Technical Symposium on Computer Science Education, 1996Co-Authors: Suzanne W Dietrich, Susan D UrbanAbstract:This paper describes the use of cooperative group learning concepts in support of an undergraduate Database management course that emphasizes the theoretical and practical aspects of Database application development. The course project is divided into three main phases, involving requirements analysis and conceptual design, relational Database mapping and prototyping, and Database system implementation using Microsoft Access. The project deliverables are designed so that students not only develop a Database implementation, but also evaluate their design in terms of functional dependencies, normal forms, the lossless join property, and the dependency preservation property, thus establishing the need for sound Database design principles. Students are required to actively participate in each phase, with students assuming different roles in each phase to allow them to experience different leadership responsibilities. As part of the grading process, students evaluate their own performance as well as the performance of others in the group. This paper describes our experience with the structure and administration of cooperative groups and provides a discussion of the lessons we have learned, including initial observations of the effectiveness of the approach.
-
SIGCSE - Database Theory in practice: learning from cooperative group projects
Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education - SIGCSE '96, 1996Co-Authors: Suzanne W Dietrich, Susan D UrbanAbstract:This paper describes the use of cooperative group learning concepts in support of an undergraduate Database management course that emphasizes the theoretical and practical aspects of Database application development. The course project is divided into three main phases, involving requirements analysis and conceptual design, relational Database mapping and prototyping, and Database system implementation using Microsoft Access. The project deliverables are designed so that students not only develop a Database implementation, but also evaluate their design in terms of functional dependencies, normal forms, the lossless join property, and the dependency preservation property, thus establishing the need for sound Database design principles. Students are required to actively participate in each phase, with students assuming different roles in each phase to allow them to experience different leadership responsibilities. As part of the grading process, students evaluate their own performance as well as the performance of others in the group. This paper describes our experience with the structure and administration of cooperative groups and provides a discussion of the lessons we have learned, including initial observations of the effectiveness of the approach.
Jan Van Den Bussche - One of the best experts on this subject based on the ideXlab platform.
-
Fields of Logic and Computation - Database Theory, Yuri, and me
Fields of Logic and Computation, 2010Co-Authors: Jan Van Den BusscheAbstract:Yuri Gurevich made many varied and deep contributions to logic for computer science. Logic provides also the theoretical foundation of Database systems. Hence, it is almost unavoidable that Gurevich made some great contributions to Database Theory. We discuss some of these contributions, and, along the way, present some personal anecdotes connected to Yuri and the author. We also describe the honorary doctorate awarded to Gurevich by Hasselt University (then called Limburgs Universitair Centrum) in 1998.
-
Database Theory column
ACM SIGACT News, 2006Co-Authors: Jan Van Den BusscheAbstract:The 25th edition of the ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Databases (PODS), took place from 26 to 29 June 2006, at the Renaissance Chicago Hotel in Chicago. As usual since 1991, the symposium was organized jointly with the ACM SIGMOD International Conference on Management of Data. While SIGMOD focuses on practical aspects of Database systems, PODS focuses on the Theory of such systems. The joint organization stimulates interaction between systems and Theory research.
-
Database Theory - Preface
2003Co-Authors: Vianu, Jan Van Den BusscheAbstract:Limburgs Univ Ctr, Dept WNI, B-3590 Diepenbeek, Belgium. Univ Calif San Diego, Inst Comp Sci & Engn, La Jolla, CA 92093 USA.Van den Bussche, J, Limburgs Univ Ctr, Dept WNI, B-3590 Diepenbeek, Belgium.
-
applications of alfred tarski s ideas in Database Theory
Computer Science Logic, 2001Co-Authors: Jan Van Den BusscheAbstract:Many ideas of Alfred Tarski - one of the founders of modern logic - find application in Database Theory. We survey some of them with no attempt at comprehensiveness. Topics discussed include the genericity of Database queries; the relational algebra, the Tarskian definition of truth for the relational calculus, and cylindric algebras; relation algebras and computationally complete query languages; real polynomial constraint Databases; and geometrical query languages.
-
CSL - Applications of Alfred Tarski's Ideas in Database Theory
Computer Science Logic, 2001Co-Authors: Jan Van Den BusscheAbstract:Many ideas of Alfred Tarski - one of the founders of modern logic - find application in Database Theory. We survey some of them with no attempt at comprehensiveness. Topics discussed include the genericity of Database queries; the relational algebra, the Tarskian definition of truth for the relational calculus, and cylindric algebras; relation algebras and computationally complete query languages; real polynomial constraint Databases; and geometrical query languages.
