Acerca de la dependencia de existencia en la modelación de datos
Fecha
2008-07-08
Autores
Cabrera González, Norma Elisa
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Editor
Universidad Central “Marta Abreu” de Las Villas
Resumen
En la infraestructura de todo sistema de información, la exactitud semántica de los datos es vital para garantizar la calidad de las aplicaciones que los utilizan. La especificación de cuándo y cuáles datos son semánticamente correctos, constituye una de las tareas más importantes en la modelación de datos, donde la lógica del negocio y los requisitos que definen los usuarios son traducidas en restricciones de integridad semánticas. Los modelos de datos proporcionan diferentes medios para representar las restricciones de integridad, en la modelación conceptual la dependencia de existencia es un recurso útil para asegurar la integridad semántica entre las propiedades estáticas y dinámicas de los datos.
En general, las restricciones de integridad son captadas a nivel conceptual y deben ser transformadas adecuadamente para su soporte en el nivel lógico, particularmente la dependencia de existencia queda modelada en los esquemas relacionales a través de las llaves foráneas y su comportamiento. A pesar de la utilidad que puede tener este estudio no solo para la modelación de datos en ambientes centralizados, sino incluso en ambientes distribuidos, en la literatura se describe de forma intuitiva y no está debidamente abordada. En este trabajo se hace un análisis de las distintas construcciones que reflejan de alguna manera dependencia de existencia y se modela su comportamiento sobre la base de sus particularidades. Además, se analiza la aplicación de la dependencia de existencia en asociaciones para la fragmentación horizontal derivada en el marco de bases de datos distribuidas.
In the infrastructure of any information system, the semantic accuracy of the information is vital to guarantee the quality of the applications that use them. The specification of when and which information is semantically correct, constitute one of the most important tasks in the modeling of information, where the logic of the business and the requisites that the users define are translated in semantic restrictions of integrity. The information models provide different means to represent the integrity restrictions, in the conceptual modeling the existence dependency is a useful resource to assure the semantic integrity between the static and dynamic properties of the information. In general, the integrity restrictions are received at conceptual level and they must be transformed appropriately for his support in the logical level, particularly the existence dependency is modeled in the schemes related through the foreign keys and his behavior. In spite of the utility that can have this study for the modeling of information in centralized ambiences, but even in distributed ambiences, in the literature it is described of intuitive form and is not tackled properly. In this work is made an analysis of the different constructions that reflect somehow existence dependency and his behavior models itself on the base of his peculiarities. Also, there is analyzed the application of the existence dependency in affiliations for the horizontal fragmentation derived in the frame of distributed databases.
In the infrastructure of any information system, the semantic accuracy of the information is vital to guarantee the quality of the applications that use them. The specification of when and which information is semantically correct, constitute one of the most important tasks in the modeling of information, where the logic of the business and the requisites that the users define are translated in semantic restrictions of integrity. The information models provide different means to represent the integrity restrictions, in the conceptual modeling the existence dependency is a useful resource to assure the semantic integrity between the static and dynamic properties of the information. In general, the integrity restrictions are received at conceptual level and they must be transformed appropriately for his support in the logical level, particularly the existence dependency is modeled in the schemes related through the foreign keys and his behavior. In spite of the utility that can have this study for the modeling of information in centralized ambiences, but even in distributed ambiences, in the literature it is described of intuitive form and is not tackled properly. In this work is made an analysis of the different constructions that reflect somehow existence dependency and his behavior models itself on the base of his peculiarities. Also, there is analyzed the application of the existence dependency in affiliations for the horizontal fragmentation derived in the frame of distributed databases.
Descripción
Palabras clave
Dependencia de Existencia, Modelación de Datos, Sistema de Información, Restricciones de Integridad, Bases de Datos Distribuidas