Data/hora: 10/06/2024 00:59:51

Biblioteca(s): 	Embrapa Agricultura Digital.	
Data corrente: 	20/03/1998	
Data da última atualização: 	19/12/2007	
Autoria: 	BOUDJLIDA, N.; PERRIN, O.	
Título: 	Schema updates and database restructuring.	
Ano de publicação: 	1997	
Fonte/Imprenta: 	In: SIMPÓSIO BRASILEIRO DE BANCO DE DADOS, 12., 1997, Fortaleza. Anais... Fortaleza: UFC, 1997.	
Páginas: 	p.210-225.	
Idioma: 	Inglês	
Notas: 	SBBD'97. Editado por Vânia Maria Ponte Vidal.	
Conteúdo: 	Changing a database schema may affect existing data instances and programs. To deal with the side effects of schema changes on both data and programs, data must migrate to the modified schema and programs must be adapted to the modified data structures. Indeed, due to the long duration of some activities using databases, like software engineering, it is a critical need to manage several versions of a database schema. So, a piece of that must be viewed as an instance of more than one data schema. Most of the current approaches related to this research area only deal with atomic changes and do not provide a real help to achieve program adaptation follow up complex changes. Our aim is to propose a set of services which may be used to implement both data migration and program adaptation after schema changes. So, we propose a mechanism based on the identification of relationships between the data schema before the change and after the change. Such relationships help to define mapping functions as schema homomorphisms, which may be used in both data and program adaptation. Mappings are related to atomic as well as complex changes. This work is founded on a generic object-relationship data representation model on which three classes of change operations are identified and examined. Renaming operations, domain change operations and type restructuring operations. The proposed approach is analyzed for every class of schema change operations.	
Palavras-Chave: 	Banco de dados.	
Thesaurus Nal: 	databases.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Agricultura Digital (CNPTIA)	
Exemplares: 	CNPTIA - (6784-1) - ADD - PL - -- - 005.74 - SIM - 1997.00018 - DIS