The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Carlo Zaniolo - One of the best experts on this subject based on the ideXlab platform.
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logical foundations of continuous query Languages for data streams
International conference on Datalog in Academia and Industry, 2012Co-Authors: Carlo ZanioloAbstract:Data Stream Management Systems (DSMS) have attracted much interest from the Database community, and extensions of relational Database Languages were proposed for expressing continuous queries on data streams. However, while relational Databases were built on the solid bedrock of logic, the same cannot be said for DSMS. Thus, a logic-based reconstruction of DSMS Languages and their unique computational model is long overdue. Indeed, the banning of blocking queries and the fact that stream data are ordered by their arrival timestamps represent major new aspects that have yet to be characterized by simple theories. In this paper, we show that these new requirements can be modeled using the familiar deductive Database concepts of closed-world assumption and explicit local stratification. Besides its obvious theoretical interest, this approach leads to the design of a powerful version of Datalog for data streams. This language is called Streamlog and takes the query and application Languages of DSMS to new levels of expressive power, by removing the unnecessary limitations that severely impair current commercial systems and research prototypes.
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DBPL - User-Defined Aggregates in Database Languages
Research Issues in Structured and Semistructured Database Programming, 2000Co-Authors: Haixun Wang, Carlo ZanioloAbstract:User-defined aggregates (UDAs) can be the linchpin of sophisticated data mining functions and other advanced Database applications, but they find little support in current Database systems. In this paper, we describe the SQL-AG prototype that overcomes these limitations by supporting UDAs as originally proposed in Postgres and SQL3. Then we extend the power and flexibility of UDAs by adding (i) early returns, (to express online aggregation) and (ii) syntactically recognizable monotonic UDAs that can be used in recursive queries to support applications, such as Bill of Materials (BoM) and greedy algorithms for graph optimization, that cannot be expressed under stratified aggregation. T his paper proposes a unified solution to both the theoretical and practical problems of UDAs, and demonstrates the power of UDAs in dealing with advanced Database applications.
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user defined aggregates in Database Languages
Database Programming Languages, 1999Co-Authors: Haixun Wang, Carlo ZanioloAbstract:User-defined aggregates (UDAs) can be the linchpin of sophisticated data mining functions and other advanced Database applications, but they find little support in current Database systems. In this paper, we describe the SQL-AG prototype that overcomes these limitations by supporting UDAs as originally proposed in Postgres and SQL3. Then we extend the power and flexibility of UDAs by adding (i) early returns, (to express online aggregation) and (ii) syntactically recognizable monotonic UDAs that can be used in recursive queries to support applications, such as Bill of Materials (BoM) and greedy algorithms for graph optimization, that cannot be expressed under stratified aggregation. T his paper proposes a unified solution to both the theoretical and practical problems of UDAs, and demonstrates the power of UDAs in dealing with advanced Database applications.
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universal temporal extensions for Database Languages
International Conference on Data Engineering, 1999Co-Authors: Cindy X Chen, Carlo ZanioloAbstract:Temporal reasoning and temporal query Languages present difficult research problems of theoretical interest and practical importance. One problem is the chasm between point-based temporal reasoning and interval-based reasoning. Another problem is the lack of robustness and universality in many proposed solutions, whereby temporal extensions designed for one language cannot be easily applied to other query Languages, e.g. extensions proposed for SQL cannot be applied to QBE or Datalog. In this paper, we provide a simple solution to both problems by observing that all query Languages support (i) single-value-based reasoning, and (ii) aggregate-based reasoning, and then showing that these two modalities can be naturally extended to support, respectively, point-based and interval-based temporal queries. We follow TSQL2 insofar as practical requirements are concerned, and show that its functionality can be captured by simpler constructs which can be applied uniformly to Datalog, QBE and SQL. Then, we show that an efficient implementation can be achieved by mapping into a different storage representation, and discuss a prototype built along these lines using the /spl Lscr//spl Dscr//spl Lscr/++ system with extended aggregates.
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ICDE - Universal temporal extensions for Database Languages
Proceedings 15th International Conference on Data Engineering (Cat. No.99CB36337), 1999Co-Authors: Cindy X Chen, Carlo ZanioloAbstract:Temporal reasoning and temporal query Languages present difficult research problems of theoretical interest and practical importance. One problem is the chasm between point-based temporal reasoning and interval-based reasoning. Another problem is the lack of robustness and universality in many proposed solutions, whereby temporal extensions designed for one language cannot be easily applied to other query Languages, e.g. extensions proposed for SQL cannot be applied to QBE or Datalog. In this paper, we provide a simple solution to both problems by observing that all query Languages support (i) single-value-based reasoning, and (ii) aggregate-based reasoning, and then showing that these two modalities can be naturally extended to support, respectively, point-based and interval-based temporal queries. We follow TSQL2 insofar as practical requirements are concerned, and show that its functionality can be captured by simpler constructs which can be applied uniformly to Datalog, QBE and SQL. Then, we show that an efficient implementation can be achieved by mapping into a different storage representation, and discuss a prototype built along these lines using the /spl Lscr//spl Dscr//spl Lscr/++ system with extended aggregates.
Mengchi Liu - One of the best experts on this subject based on the ideXlab platform.
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a logical foundation for deductive object oriented Databases
ACM Transactions on Database Systems, 2002Co-Authors: Mengchi Liu, Gillian Dobbie, Tok Wang LingAbstract:Over the past decade, a large number of deductive object-oriented Database Languages have been proposed. The earliest of these Languages had few object-oriented features, and more and more features have systematically been incorporated in successive Languages. However, a language with a clean logical semantics that naturally accounts for all the key object-oriented features, is still missing from the literature. This article takes us another step towards solving this problem. Two features that are currently missing are the encapsulation of rule-based methods in classes, and nonmonotonic structural and behavioral inheritance with overriding, conflict resolution and blocking. This article introduces the syntax of a language with these features. The language is restricted in the sense that we have omitted other object-oriented and deductive features that are now well understood, in order to make our contribution clearer. It then defines a class of Databases, called well-defined Databases, that have an intuitive meaning and develops a direct logical semantics for this class of Databases. The semantics is based on the well-founded semantics from logic programming. The work presented in this article establishes a firm logical foundation for deductive object-oriented Databases.
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a logical foundation for deductive object oriented Databases
Database Systems for Advanced Applications, 2001Co-Authors: Mengchi Liu, Gillian Dobbie, Tok Wang LingAbstract:Over the past decade, a large number of deductive object-oriented Database Languages have been proposed. The earliest of these Languages had few object-oriented features, and more and more features have systematically been incorporated in successive Languages. However, a language with a clean logical semantics that naturally accounts for all the key object-oriented features, is still missing from the literature. Two features that are currently missing are the encapsulation of rule-based methods in classes, and nonmonotonic behavioral inheritance with overriding, conflict resolution and blocking. This paper introduces the syntax of a language with these features. It then defines a class of Databases, called well-defined Databases, that have an intuitive meaning and develops a direct logical semantics for this class of Databases. The semantics is based on the well-founded semantics from logic programming. The work presented in this paper establishes a firm logical foundation for deductive object-oriented Databases.
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deductive Database Languages problems and solutions
ACM Computing Surveys, 1999Co-Authors: Mengchi LiuAbstract:Deductive Databases result from the integration of relational Database and logic programming techniques. However, significant problems remain inherent in this simple synthesis from the language point of view. In this paper, we discuss these problems from four different aspects: complex values, object orientation, higher-orderness, and updates. In each case, we examine four typical Languages that address the corresponding issues.
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NGITS - OLOG: A Deductive Object Database Language
Next Generation Information Technologies and Systems, 1999Co-Authors: Mengchi LiuAbstract:Deductive object-oriented Databases are intended to combine the best of the deductive and object-oriented approaches. However, some important object-oriented features are not properly supported in the existing proposals. This paper proposes a novel deductive language that supports important structurally object-oriented features such as object identity, complex objects, typing, classes, class hierarchies, multiple property inheritance with overriding, conflict-handling, and blocking, and schema definitions in a uniform framework. The language effectively integrates useful features in deductive and object-oriented Database Languages. The main novel feature is the logical semantics that cleanly accounts for those structurally object-oriented features that are missing in object-oriented Database Languages. Therefore it establishes a theoretical foundation for a practical deductive object-oriented Database system for advanced Database applications.
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incorporating methods and encapsulation into deductive object oriented Database Languages
Database and Expert Systems Applications, 1998Co-Authors: Mengchi LiuAbstract:This paper presents an approach to incorporating rule-based methods and encapsulation of such methods into DOOD Languages. The main novel feature of this approach is the simple and intuitive logic-based semantics that cleanly accounts for all important object-oriented features such as object identity, complex objects, typing, methods, encapsulation, class hierarchy, multiple structural and behavioral inheritance with overridden, and schema definition. Besides, the set-at-a-time semantics that is natural for Database updates is also novel.
Mohand-said Hacid - One of the best experts on this subject based on the ideXlab platform.
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A Logical Approach to Quality of Service Specification in Video Databases
Multimedia Tools and Applications, 2004Co-Authors: Enrico Bertino, Ahmed K. Elmagarmid, Mohand-said HacidAbstract:Quality of Service (QoS) is defined as a set of perceivable attributes expressed in a user-friendly language with parameters that may be objective or subjective. Objective parameters are those related to a particular service and are measurable and verifiable. Subjective parameters are those based on the opinions of the end-users. We believe that quality of service should become an integral part of multimedia Database systems and users should be able to query by requiring a quality of service from the system. The specification and enforcement of QoS presents an interesting challenge in multimedia systems development. A deal of effort has been done on QoS specification and control at the system and the network levels, but less work has been done at the application/user level. In this paper, we propose a language, in the style of constraint Database Languages, for formal specification of QoS constraints. The satisfaction by the system of the user quality requirements can be viewed as a constraint satisfaction problem, and the negotiation can be viewed as constraint optimization. We believe this paper represents a first step towards the development of a Database framework for quality of service management in video Databases. The contribution of this paper lies in providing a logical framework for specifying and enforcing quality of service in video Databases. To our knowledge, this work is the first from a Database perspective on quality of service management.
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Quality of Service Specification in Video Databases
IEEE MultiMedia, 2003Co-Authors: Elisa Bertino, Ahmed K. Elmagarmid, Tiziana Catarci, Mohand-said HacidAbstract:Quality of Service (QoS) is defined as a set of perceivable attributes expressed in a user-friendly language with parameters that may be subjective or objective. Objective parameters are those related to a particular service and are measurable and verifiable. Subjective parameters are those based on the opinions of the end-users. We believe that quality of service should become an integral part of multimedia Database systems and users should be able to query by requiring a quality of service from the system. The specification and enforcement of QoS presents an interesting challenge in multimedia systems development. A deal of effort has been done on QoS specification and control at the system and the network levels, but less work has been done at the application/user level. In this paper, we propose a language, in the style of constraint Database Languages, for formal specification of QoS constraints. The satisfaction by the system of the user quality requirements can be viewed as a constraint satisfaction problem, and the negotiation can be viewed as constraints relaxation. We believe this paper represents a first step towards the development of a formal framework for quality of service management in video Databases.
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A Database Approach to Quality of Service Specification in Video Databases
SIGMOD record, 2003Co-Authors: Elisa Bertino, Ahmed K. Elmagarmid, Mohand-said HacidAbstract:Quality of Service (QoS) is defined as a set of perceivable attributes expressed in a user-friendly language with parameters that may be subjective or objective. Objective parameters are those related to a particular service and are measurable and verifiable. Subjective parameters are those based on the opinions of the end-users. We believe that quality of service should become an integral part of multimedia Database systems and users should be able to query by requiring a quality of service from the system. The specification and enforcement of QoS presents an interesting challenge in multimedia systems development. A deal of effort has been done on QoS specification and control at the system and the network levels, but less work has been done at the application/user level. In this paper, we propose a language, in the style of constraint Database Languages, for formal specification of QoS constraints. The satisfaction by the system of the user quality requirements can be viewed as a constraint satisfaction problem. We believe this paper represents a first step towards the development of a Database framework for quality of service management in video Databases. The contribution of this paper lies in providing a logical framework for specifying and enforcing quality of service in video Databases. To our knowledge, this work is the first from a Database perspective on quality of service management.
Cindy X Chen - One of the best experts on this subject based on the ideXlab platform.
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universal temporal extensions for Database Languages
International Conference on Data Engineering, 1999Co-Authors: Cindy X Chen, Carlo ZanioloAbstract:Temporal reasoning and temporal query Languages present difficult research problems of theoretical interest and practical importance. One problem is the chasm between point-based temporal reasoning and interval-based reasoning. Another problem is the lack of robustness and universality in many proposed solutions, whereby temporal extensions designed for one language cannot be easily applied to other query Languages, e.g. extensions proposed for SQL cannot be applied to QBE or Datalog. In this paper, we provide a simple solution to both problems by observing that all query Languages support (i) single-value-based reasoning, and (ii) aggregate-based reasoning, and then showing that these two modalities can be naturally extended to support, respectively, point-based and interval-based temporal queries. We follow TSQL2 insofar as practical requirements are concerned, and show that its functionality can be captured by simpler constructs which can be applied uniformly to Datalog, QBE and SQL. Then, we show that an efficient implementation can be achieved by mapping into a different storage representation, and discuss a prototype built along these lines using the /spl Lscr//spl Dscr//spl Lscr/++ system with extended aggregates.
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ICDE - Universal temporal extensions for Database Languages
Proceedings 15th International Conference on Data Engineering (Cat. No.99CB36337), 1999Co-Authors: Cindy X Chen, Carlo ZanioloAbstract:Temporal reasoning and temporal query Languages present difficult research problems of theoretical interest and practical importance. One problem is the chasm between point-based temporal reasoning and interval-based reasoning. Another problem is the lack of robustness and universality in many proposed solutions, whereby temporal extensions designed for one language cannot be easily applied to other query Languages, e.g. extensions proposed for SQL cannot be applied to QBE or Datalog. In this paper, we provide a simple solution to both problems by observing that all query Languages support (i) single-value-based reasoning, and (ii) aggregate-based reasoning, and then showing that these two modalities can be naturally extended to support, respectively, point-based and interval-based temporal queries. We follow TSQL2 insofar as practical requirements are concerned, and show that its functionality can be captured by simpler constructs which can be applied uniformly to Datalog, QBE and SQL. Then, we show that an efficient implementation can be achieved by mapping into a different storage representation, and discuss a prototype built along these lines using the /spl Lscr//spl Dscr//spl Lscr/++ system with extended aggregates.
Tok Wang Ling - One of the best experts on this subject based on the ideXlab platform.
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a logical foundation for deductive object oriented Databases
ACM Transactions on Database Systems, 2002Co-Authors: Mengchi Liu, Gillian Dobbie, Tok Wang LingAbstract:Over the past decade, a large number of deductive object-oriented Database Languages have been proposed. The earliest of these Languages had few object-oriented features, and more and more features have systematically been incorporated in successive Languages. However, a language with a clean logical semantics that naturally accounts for all the key object-oriented features, is still missing from the literature. This article takes us another step towards solving this problem. Two features that are currently missing are the encapsulation of rule-based methods in classes, and nonmonotonic structural and behavioral inheritance with overriding, conflict resolution and blocking. This article introduces the syntax of a language with these features. The language is restricted in the sense that we have omitted other object-oriented and deductive features that are now well understood, in order to make our contribution clearer. It then defines a class of Databases, called well-defined Databases, that have an intuitive meaning and develops a direct logical semantics for this class of Databases. The semantics is based on the well-founded semantics from logic programming. The work presented in this article establishes a firm logical foundation for deductive object-oriented Databases.
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a logical foundation for deductive object oriented Databases
Database Systems for Advanced Applications, 2001Co-Authors: Mengchi Liu, Gillian Dobbie, Tok Wang LingAbstract:Over the past decade, a large number of deductive object-oriented Database Languages have been proposed. The earliest of these Languages had few object-oriented features, and more and more features have systematically been incorporated in successive Languages. However, a language with a clean logical semantics that naturally accounts for all the key object-oriented features, is still missing from the literature. Two features that are currently missing are the encapsulation of rule-based methods in classes, and nonmonotonic behavioral inheritance with overriding, conflict resolution and blocking. This paper introduces the syntax of a language with these features. It then defines a class of Databases, called well-defined Databases, that have an intuitive meaning and develops a direct logical semantics for this class of Databases. The semantics is based on the well-founded semantics from logic programming. The work presented in this paper establishes a firm logical foundation for deductive object-oriented Databases.
