www.uhasselt.be
DSpace

Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/655

Title: Nested Data Cubes for OLAP
Authors: Dekeyser, Stijn
KUIJPERS, Bart
Paredaens, Jan
Wijsen, Jef
Issue Date: 1998
Publisher: Springer-Verlag
Citation: ADVANCES IN DATABASE TECHNOLOGIES. p. 129-140
Series/Report: LECTURE NOTES IN COMPUTER SCIENCE, 1552
Abstract: We present a new model for OLAP, called the nested data cube (NDC) model. Nested data cubes are a generalization of other OLAP models such as f-tables [3], and hypercubes [2], but also of classical structures such as sets, bags, and relations. The model we propose adds to the revious models mainly flexibility in viewing the data, in that it allows for the assignment of priorities to the different dimensions of the multidimensional OLAP data. We also present an algebra in which all typical OLAP analysis and navigation operations can be formulated. We present a number of algebraic operators that work on nested data cubes and that preserve the functional dependency between the dimensional coordinates of the data cube and the factual data in it. These operations include nesting, unnesting, summary, roll-up, and aggregation operations. We show how these operations can be applied to sub-NDC’s at any depth, and also show that the NDC algebra can express the SPJR algebra [1] of the relational model. A major motivation for defining an algebra rather than a calculus, is that an algebra naturally leads to an implementation strategy. Importantly, we show that the NDC algebra primitives can be implemented by linear time algorithms.
URI: http://hdl.handle.net/1942/655
DOI: 10.1007/b71656
ISI #: 000087625100011
ISBN: 3-540-65690-1
Type: Journal Contribution
Appears in Collections: Research publications

Files in This Item:

Description SizeFormat
N/A173.5 kBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.