Supporting OLAP operations over imperfectly integrated taxonomies

OLAP is an important tool in decision support. With the help of domain knowledge, such as hierarchies of attribute values, OLAP helps the user observe the effects of various decisions. One assumption of most OLAP operations is that the available domain knowledge is precise. In particular, they assume that the hierarchy of values over which the user can navigate forms a taxonomy. In this paper, we first note that when multiple heterogeneous data sources are involved in the gathering of the data and the associated domain knowledge, the integrated knowledge-base, constructed by combining locally available taxonomies based on the concept matchings, may not be a taxonomy itself. Specifically, existence of intersections among concepts from different sources compromises the tree-structure of the integrated taxonomy and prevents effective use of hierarchical navigation techniques, such as drill-down and roll-up. To cope with this, we introduce concept un-classification, where a select few of ...

• Type: Journal
• Year: 2008
• Where: SIGMOD
• Authors: Yan Qi 0002, K. Selçuk Candan, Jun'ichi Tatemura, Songting Chen, Fenglin Liao
• Keywords: Database, Domain Knowledge, OLAP, SIGMOD 2008, Taxonomy