QC-Trees: An Efficient Summary Structure for Semantic OLAP

Recently, a technique called quotient cube was proposed as a summary structure for a data cube that preserves its semantics, with applications for online exploration and visualization. The authors showed that a quotient cube can be constructed very efficiently and it leads to a significant reduction in the cube size. While it is an interesting proposal, that paper leaves many issues unaddressed. Firstly, a direct representation of a quotient cube is not as compact as possible and thus still wastes space. Secondly, while a quotient cube can in principle be used for answering queries, no specific algorithms were given in the paper. Thirdly, maintaining any summary structure incrementally against updates is an important task, a topic not addressed there. In this paper, we propose an efficient data structure called QC-tree and an efficient algorithm for directly constructing it from a base table, solving the first problem. We give efficient algorithms that address the remaining questions....

• Type: Conference
• Year: 2003
• Where: SIGMOD
• Authors: Laks V. S. Lakshmanan, Jian Pei, Yan Zhao
• Keywords: Cube Size, Database, Quotient Cube, SIGMOD 2003, Technique Called Quotient