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  • Automated reasoning on UML conceptual schemas with derived information and queries

     Farré Tost, Carles; Queralt Calafat, Anna; Rull Fort, Guillem; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Information and software technology
    Date of publication: 2013-09-04
    Journal article

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    Context: It is critical to ensure the quality of a software system in the initial stages of development, and several approaches have been proposed to ensure that a conceptual schema correctly describes the user¿s requirements. Objective: The main goal of this paper is to perform automated reasoning on UML schemas containing arbitrary constraints, derived roles, derived attributes and queries, all of which must be specified by OCL expressions. Method: The UML/OCL schema is encoded in a first order logic formalisation, and an existing reasoning procedure is used to check whether the schema satisfies a set of desirable properties. Due to the undecidability of reasoning in highly expressive schemas, such as those considered here, we also provide a set of conditions that, if satisfied by the schema, ensure that all properties can be checked in a finite period of time. Results: This paper extends our previous work on reasoning on UML conceptual schemas with OCL constraints by considering derived attributes and roles that can participate in the definition of other constraints, queries and derivation rules. Queries formalised in OCL can also be validated to check their satisfiability and to detect possible equivalences between them. We also provide a set of conditions that ensure finite reasoning when they are satisfied by the schema under consideration. Conclusion: This approach improves upon previous work by allowing automated reasoning for more expressive UML/OCL conceptual schemas than those considered so far.

  • Validation of schema mappings with nested queries

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Computer Science and Information Systems
    Date of publication: 2013-01
    Journal article

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    With the emergence of the Web and the wide use of XML for representing data, the ability to map not only flat relational but also nested data has become crucial. The design of schema mappings is a semi-automatic process. A human designer is needed to guide the process, choose among mapping candidates, and successively refine the mapping. The designer needs a way to figure out whether the mapping is what was intended. Our approach to mapping validation allows the designer to check whether the mapping satisfies certain desirable properties. In this paper, we focus on the validation of mappings between nested relational schemas, in which the mapping assertions are either inclusions or equalities of nested queries. We focus on the nested relational setting since most XML¿s Document Type Definitions (DTDs) can be represented in this model. We perform the validation by reasoning on the schemas and mapping definition. We take into account the integrity constraints defined on both the source and target schema. We consider constraints and mapping¿s queries which may contain arithmetic comparisons and negations. This class of mapping scenarios is significantly more expressive than the ones addressed by previous work on nested relational mapping validation. We encode the given mapping scenario into a single flat database schema, so we can take advantage of our previous work on validating flat relational mappings, and reformulate each desirable property check as a query satisfiability problem.

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    Validation of schema mappings with nested queries  Open access

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2012-10-11
    Report

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    With the emergence of the Web and the wide use of XML for representing data, the ability to map not only flat relational but also nested data has become crucial. The design of schema mappings is a semi-automatic process. A human designer is needed to guide the process, choose among mapping candidates, and successively refine the mapping. The designer needs a way to figure out whether the mapping is what was intended. Our approach to mapping validation allows the designer to check whether the mapping satisfies certain desirable properties. In this paper, we focus on the validation of mappings between nested relational schemas, in which the mapping assertions are either inclusions or equalities of nested queries. We focus on the nested relational setting since most XML’s Document Type Definitions (DTDs) can be represented in this model. We perform the validation by reasoning on the schemas and mapping definition. We take into account the integrity constraints defined on both the source and target schema.

  • Validation of Mappings between Data Schemas  Open access

     Rull Fort, Guillem
    Defense's date: 2011-01-19
    Department of Software, Universitat Politècnica de Catalunya
    Theses

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    En esta tesis, presentamos un nuevo enfoque para validar mappings entre esquemas de datos que permite al diseñador comprobar si el mapping satisface o no ciertas propiedades deseables. La respuesta que obtiene el diseñador no se limita a un simple valor booleano, sino que dependiendo del resultado de la comprobación obtendrá un ejemplo/contraejemplo que ilustre ese resultado, o bien se le indicará el conjunto de restricciones de integridad de los esquemas y formulas del mapping responsables de ese resultado. Una de las características principales de nuestro enfoque es que es capaz de tratar una clase muy expresiva de mappings y esquemas relacionales. En particular, nuestro enfoque es capaz de tratar con formulas de mapping consistentes en inclusiones y igualdades de consultas, además de permitir el uso de negaciones y comparaciones aritméticas tanto en las propias formulas del mapping como en las vistas definidas en los esquemas. Nuestro enfoque también permite tratar restricciones de integridad, las cuales pueden estar definidas no solo sobre las tablas sino también sobre las vistas de los esquemas. Dado que razonar sobre este tipo de mappings y esquemas es, desafortunadamente, indecidible, proponemos realizar un test de terminación previo a la validación del mapping. Si el test de terminación da una respuesta positiva, entonces podremos estar seguros de que la posterior comprobación de la propiedad deseable correspondiente terminará. Finalmente, también extendemos nuestro enfoque más allá del caso relacional y lo aplicamos al contexto de mappings entre esquemas XML.

    In this thesis, we present a new approach to the validation of mappings between data schemas. It allows the designer to check whether the mapping satisfies certain desirable properties. The feedback that our approach provides to the designer is not only a Boolean answer, but either a (counter)example for the (un)satisfiability of the tested property, or the set of mapping assertions and schema constraints that are responsible for that (un)satisfiability. One of the main characteristics of our approach is that it is able to deal with a very expressive class of relational mapping scenarios; in particular, it is able to deal with mapping assertions in the form of query inclusions and query equalities, and it allows the use of negation and arithmetic comparisons in both the mapping assertions and the views of the schemas; it also allows for integrity constraints, which can be defined not only over the base relations but also in terms of the views. Since reasoning on the class of mapping scenarios that we consider is, unfortunately, undecidable, we propose to perform a termination test as a pre-validation step. If the answer of the test is positive, then checking the corresponding desirable property will terminate. We also go beyond the relational setting and study the application of our approach to the context of mappings between XML schemas.

  • AuRUS: Automated Reasoning on UML/OCL Schemas

     Queralt Calafat, Anna; Rull Fort, Guillem; Teniente Lopez, Ernest; Farré Tost, Carles; Urpi Tubella, Antoni
    International Conference on Conceptual Modeling
    Presentation's date: 2010-11-02
    Presentation of work at congresses

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    To ensure the quality of an information system, the conceptual schema that represents its domain must be semantically correct. We present a prototype to automatically check whether a UML schema with OCL constraints is right in this sense. It is well known that the full expressiveness of OCL leads to undecidability of reasoning. To deal with this problem, our approach finds a compromise between expressiveness and decidability, thus being able to handle very expressive constraints guaranteeing termination in many cases.

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    A schema-only approach to validate XML schema mappings  Open access

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2010-03-19
    Report

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    Since the emergence of the Web, the ability to map XML data between different data sources has become crucial. Defining a mapping is however not a fully automatic process. The designer needs to figure out whether the mapping is what was intended. Our approach to this validation consists of defining and checking certain desirable properties of mappings. We translate the XML schemas and the mapping into first-order logic formalism and apply a reasoning mechanism to check the desirable properties automatically, without assuming any particular instantiation of the schemas.

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    Testing termination of query satisfiability checking on expressive database schemas  Open access

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2010-03-19
    Report

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    A query is satisfiable if there is at least one consistent instance of the database in which it has a non-empty answer. Defining queries on a database schema and checking their satisfiability can help the database designer to be sure whether the produced database schema is what was intended. The formulation of such queries may easily require the use of some arithmetic comparisons or negated expressions. Unfortunately, checking the satisfiability of this class of queries on a database schema that most likely have some integrity constraints (e.g., keys, foreign keys, Boolean checks) is, in general, undecidable. However, although the problem is undecidable for such a class of schemas and queries, it may not be so for a particular query satisfiability check. In this paper, we propose to perform a termination test as a previous step to query satisfiability checking. If positive, the termination test guarantees that the corresponding query satisfiability check will terminate. We assume the CQC method is the underlying query satisfiability checking method; to the best of our knowledge, it is the only method of this kind able to deal with schemas and queries as expressive as the ones we consider.

  • METODOS Y HERRAMIENTAS PARA LA VALIDACION Y LA GENERACION DE MAPPINGS ENTRE ESQUEMAS DE DATOS

     Queralt Calafat, Anna; Rull Fort, Guillem; Urpi Tubella, Antoni; Abello Gamazo, Alberto; Farré Tost, Carles; Romero Moral, Oscar; Teniente Lopez, Ernest
    Participation in a competitive project

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  • MVT: a schema mapping validation tool

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    International Conference on Extending Database Technology
    Presentation's date: 2009-03-24
    Presentation of work at congresses

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    Schema mappings define relationships between schemas in a declarative way. We demonstrate MVT, a mapping validation tool that allows the designer to ask whether the mapping has certain desirable properties. The answers to these questions will provide information on whether the mapping adequately matches the intended needs and requirements. MVT is able to deal with a highly expressive class of mappings and database schemas, which allows the use of negations, order comparisons and null values. The tool does not only provide a Boolean answer as test result, but also a feedback for that result. Depending on the tested property and on the test result, the provided feedback can be in the form of example schema instances, or in the form of an explanation, that is, highlighting the mapping assertions and schema constraints responsible for getting such a result.

  • Validation of mappings between schemas

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Data and knowledge engineering
    Date of publication: 2008-09
    Journal article

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  • Providing Explanations for Database Schema Validation

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Lecture notes in computer science
    Date of publication: 2008-09
    Journal article

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  • Qualidade em sites na área da saúde (SALUS)

     Abello Gamazo, Alberto; Palazzo, José; Farré Tost, Carles; Romero Moral, Oscar; García, Roberto; Oliva, Marta
    Participation in a competitive project

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  • Providing Explanations for Database Schema Validation

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2008-04
    Report

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  • SVTe: a tool to validate database schemas

     Farré Tost, Carles; Rull Fort, Guillem; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    1st International Workshop on Testing Database Systems
    Presentation of work at congresses

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  • Containment of Conjunctive Queries over Databases with Null

     Urpi Tubella, Antoni; Farré Tost, Carles; Teniente Lopez, Ernest
    Lecture notes in computer science
    Date of publication: 2007-01
    Journal article

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  • Computing explanations for unlively queries in databases

     Rull Fort, Guillem; Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    ACM International Conference on Information and Knowledge Management
    Presentation of work at congresses

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  • Validation of Mappings between Schemas

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2007-06
    Report

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  • Computing Explanations for Unlively Queries in Databases

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2007-06
    Report

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  • Contención de consultas con valores nulos usando el método CQC

     Farré Tost, Carles; Urpi Tubella, Antoni
    XI Jornadas de Ingeniería del Software y Bases de Datos (JISBD 2006)
    Presentation of work at congresses

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  • Checking query containment with the CQC method

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Data and knowledge engineering
    Date of publication: 2005-05
    Journal article

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  • Desarrollo de técnicas y herramientas para la validación de esquemas de bases de datos

     Teniente Lopez, Ernest; Abello Gamazo, Alberto; Urpi Tubella, Antoni; Farré Tost, Carles
    Participation in a competitive project

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  • SVT: schema validation tool for Microsoft SQL-Server

     Teniente Lopez, Ernest; Farré Tost, Carles; Urpi Tubella, Antoni; Beltrán, Carlos; Gañán, David
    30th International Conference on Very Large Data Bases
    Presentation of work at congresses

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  • A new approach for checking schema validation properties

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    15th International Conference on Database and Expert Systems Applications. DEXA 2004
    Presentation of work at congresses

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  • Query Containment with Negated IDB Predicates

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Lecture notes in computer science
    Date of publication: 2003-09
    Journal article

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  • A NEW METHOD FOR QUERY CONTAINMENT CHECKING IN DATABASES

     Farré Tost, Carles
    Defense's date: 2003-07-10
    Department of Software, Universitat Politècnica de Catalunya
    Theses

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  • Query Containment with Negated IDB Predicates

     Farré Tost, Carles
    Advances in Databases and Information Systems
    Presentation's date: 2003-09-06
    Presentation of work at congresses

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  • Enginyeria del Software Disseny II (Quarta edició)

     Farré Tost, Carles; Olive Ramon, Antoni; Quer, Carme
    Date of publication: 2003-02
    Book

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  • Handling Existential Derived Predicates in View Updating

     Urpi Tubella, Antoni; Teniente Lopez, Ernest; Farré Tost, Carles
    19th International Conference on Logic Programming
    Presentation of work at congresses

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  • Formalization And Correctness Of The CQC Method

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 2002-11
    Report

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  • Constructive Method for Query Containment Checking

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Lecture notes in computer science
    Date of publication: 1999-01
    Journal article

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  • The Constructive Method for Query Containment Checking

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    10th International Conference on Database and Expert Systems Applications. DEXA'99
    Presentation of work at congresses

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  • The Constructive Method for Query Containment Checking

     Farré Tost, Carles
    10th International Conference on Database and Expert Systems Applications. DEXA'99
    Presentation's date: 1999-08-30
    Presentation of work at congresses

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  • The Constructive Method for Query Containment Checking (extended version)

     Farré Tost, Carles; Teniente Lopez, Ernest
    Date: 1999-07
    Report

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  • Integrated treatment of updates in deductive databases: the FOLRE Project

     Mayol Sarroca, Enric; Pastor Collado, Juan Antonio; Teniente Lopez, Ernest; Urpi Tubella, Antoni; Farré Tost, Carles
    Jornadas de Investigación y Docencia en Bases de Datos
    Presentation's date: 1998
    Presentation of work at congresses

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  • Query Containment Checking as a View Updating Problem

     Farré Tost, Carles
    9th International Conference on Database and Expert Systems Applications. DEXA'98
    Presentation's date: 1998-08-24
    Presentation of work at congresses

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  • Tratamiento integrado de actualizaciones en bases de datos deductivas: el proyecto folre

     Mayol Sarroca, Enric; Pastor Collado, Juan Antonio; Teniente Lopez, Ernest; Urpi Tubella, Antoni; Farré Tost, Carles
    III JORNADAS DE INVESTIGACION Y DOCENCIA EN BASES DE DATOS (JIDBD'98)
    Presentation of work at congresses

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  • Query Containment Checking as a View Updating Problem

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    9th International Conference on Database and Expert Systems Applications. DEXA'98
    Presentation of work at congresses

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  • Query Containment Checking as a View Updating Problem

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    Date: 1998-06
    Report

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  • Comprobación del Contenimiento de consultas mediante actualización de vistas

     Farré Tost, Carles
    II Jornadas de Investigación y Docencia en Bases de Datos (JIDBD)
    Presentation's date: 1997-07-16
    Presentation of work at congresses

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  • Comprobación del Contenimiento de Consultas mediante Actualización de Vistas

     Farré Tost, Carles; Teniente Lopez, Ernest; Urpi Tubella, Antoni
    II Jornadas de Investigación y Docencia en Bases de Datos (JIDBD)
    Presentation of work at congresses

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  • Handling Conceptual Model Validation by Planning

     Costal Costa, Maria Dolors; Teniente Lopez, Ernest; Urpi Tubella, Antoni; Farré Tost, Carles
    Lecture notes in computer science
    Date of publication: 1996-06
    Journal article

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  • FOLRE: un sistema para el tratamiento integrado de actualizaciones en bases de datos

     Teniente Lopez, Ernest; Farré Tost, Carles; Martin Escofet, Carme; Mayol Sarroca, Enric; Pastor Collado, Juan Antonio; Sistac Planas, Jaume; Urpi Tubella, Antoni
    Jornadas de Investigación y Docencia en Bases de Datos
    Presentation of work at congresses

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