Normal forms for multidimensional databases

TLDR

Multidimensional databases are increasingly popular in OLAP, yet few guidelines exist for sound schema design. This paper proposes two multidimensional normal forms to address that gap. The normal forms impose constraints on summary attributes and on complex dimensional structures within a data cube. Schemas that satisfy these normal forms guarantee correct analytical results and support more efficient physical database design.

Abstract

In the area of online analytical processing (OLAP), the concept of multidimensional databases is receiving much popularity. Thus, a couple of different multidimensional data models were proposed from the research as well as from the commercial product side, each emphasizing different perspectives. However, very little work has been done investigating guidelines for good schema design within such a multidimensional data model. Based on a logical reconstruction of multidimensional schema design, this paper proposes two multidimensional normal forms. These normal forms define modeling constraints for summary attributes describing the cells within a multidimensional data cube and constraints to model complex dimensional structures appropriately. Multidimensional schemas compliant to these normal forms do not only ensure the validity of analytical computations on the multidimensional database, but also favor an efficient physical database design.