Extending complex ad-hoc OLAP
Theodore J. Johnson, Damianos Chatziantoniou · 1999
Large scale data analysis and mining activities require sophisticated information extraction queries. Many queries require complex aggregation, and many of these aggregates are non-distributive. Conventional solutions to this problem involve defining User Defined Aggregate Functions (UDAFs). However, the use of UDAFs entails several problems. Defining a new UDAF can be a significant burden for the user, and optimizing queries involving UDAFs is difficult because of the “black box” nature of the UDAF.