Elicitation and conversion of hidden objects and restrictions in a database schema
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ArticleDescription: 1 archivo (627,5 kB)Subject(s): Online resources: Summary: Mapping a database schema from one model into another, with a higher semantic capacity, is a current research subject with application in several development fields, such as schema integration and translation, migration from l e g a ~ systems and revngineering o f poor quality or no-longer accurate data models. Inclusion dependencies are one o f the most important concepts in relational databases and they are the key to perform some reengineering o f database schemas. Referential integrity restrictions (fir), a particular case o f an inclusion conslraint, requires that the set of distinct values occurring in some specified column, simple or composite (foreign key), must be a subset o f the set o f distinct primary key values drawn from the same domain. Pure inclusion dependencies (id), however, may apply between other pairs o f attributes also (alternate keys or non-keys). Database schemas containing ids frequently reveal the presence o f hidden objects and misrepresented relationships and, as a consequence, incree,se the effort to develop program applications and maintain the integrity. This work presents a heuristics for the conversion of schemas with ids into equivalent schemas with only firs. In case some irreducible ids remain, a semantic interpretation oftbeir necessity and maintenance is given.
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Biblioteca de la Facultad de Informática | Biblioteca digital | A0394 (Browse shelf(Opens below)) | Link to resource | Recurso en Línea |
Formato de archivo: PDF. -- Este documento es producción intelectual de la Facultad de Informática - UNLP (Colección BIPA/Biblioteca)
Mapping a database schema from one model into another, with a higher semantic capacity, is a current research subject with application in several development fields, such as schema integration and translation, migration from l e g a ~ systems and revngineering o f poor quality or no-longer accurate data models. Inclusion dependencies are one o f the most important concepts in relational databases and they are the key to perform some reengineering o f database schemas. Referential integrity restrictions (fir), a particular case o f an inclusion conslraint, requires that the set of distinct values occurring in some specified column, simple or composite (foreign key), must be a subset o f the set o f distinct primary key values drawn from the same domain. Pure inclusion dependencies (id), however, may apply between other pairs o f attributes also (alternate keys or non-keys). Database schemas containing ids frequently reveal the presence o f hidden objects and misrepresented relationships and, as a consequence, incree,se the effort to develop program applications and maintain the integrity. This work presents a heuristics for the conversion of schemas with ids into equivalent schemas with only firs. In case some irreducible ids remain, a semantic interpretation oftbeir necessity and maintenance is given.
ACM symposium on Applied computing (2002, mar.,11-14 : Madrid, España). Procceding. Nueva York, ACM,2002, pp. 463-469.