Operators for reclassification queries in a temporal multidimensional model

Data warehouse dimensions are usually considered to be static because their schema and data tend not to change; however, both dimension schema and dimension data can change. This paper focuses on a type of dimension data change called reclassificationwhich occurs when a member of a certain level bec...

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Autores:
Moreno, Francisco
Arango, Fernando
Tipo de recurso:
Article of journal
Fecha de publicación:
2011
Institución:
Universidad Nacional de Colombia
Repositorio:
Universidad Nacional de Colombia
Idioma:
spa
OAI Identifier:
oai:repositorio.unal.edu.co:unal/33477
Acceso en línea:
https://repositorio.unal.edu.co/handle/unal/33477
http://bdigital.unal.edu.co/23557/
http://bdigital.unal.edu.co/23557/2/
http://bdigital.unal.edu.co/23557/3/
Palabra clave:
bodegas de datos temporales
OLAP
reclasificación
período de clasificación.
temporal data warehouse
OLAP
reclassification
classification period.
Rights
openAccess
License
Atribución-NoComercial 4.0 Internacional
Description
Summary:Data warehouse dimensions are usually considered to be static because their schema and data tend not to change; however, both dimension schema and dimension data can change. This paper focuses on a type of dimension data change called reclassificationwhich occurs when a member of a certain level becomes a member of a higher level in the same dimension, e.g. when a product changes category (it is reclassified). This type of change gives rise to the notion of classification period and to a type of query that can be useful for decision-support. For example, What were total chess-set sales during first classification period in Toy category? A set of operators has been proposed to facilitate formulating this type of query and it is shown how to incorporate them in SQL, a familiar database developer language. Our operators’ expressivity is also shown because formulating such queries without using these operators usually leads to complex and non-intuitive solutions.