The R*-tree: an efficient and robust access method for points and rectangles
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
An array-based algorithm for simultaneous multidimensional aggregates
SIGMOD '97 Proceedings of the 1997 ACM SIGMOD international conference on Management of data
R-trees: a dynamic index structure for spatial searching
SIGMOD '84 Proceedings of the 1984 ACM SIGMOD international conference on Management of data
An Implementation of Hypothetical Relations
VLDB '83 Proceedings of the 9th International Conference on Very Large Data Bases
Hypothetical Queries in an OLAP Environment
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
Dynamic Update Cube for Range-sum Queries
Proceedings of the 27th International Conference on Very Large Data Bases
Efficient incremental maintenance of data cubes
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Designing what-if analysis: towards a methodology
DOLAP '06 Proceedings of the 9th ACM international workshop on Data warehousing and OLAP
What-if OLAP Queries with Changing Dimensions
ICDE '08 Proceedings of the 2008 IEEE 24th International Conference on Data Engineering
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What-if analysis is important for decision-maker to evaluate adopting new strategy and help knowledge discovery. It mostly occurs in OLAP environments, based on implementation OLAP is divided into MOLAP and ROLAP. Most research focus on ROLAP but in the industrial sector MOLAP is more common. There is relatively little work talking about what-if analysis in MOLAP environments. The challenge of what-if analysis is how to store hypothetical modified data and how these data efficiently participating cube calculation. In this paper we systemic analyze what-if analysis in MOLAP; hypothetical modified data stored as compression offset-data and is organized as HU-tree which is a variant of r*-tree. Through HU-tree we can efficient storage sparse hypothetical modified data which ordered by designed dimension order and fast retrieve. Then in cube calculation, hypothetical modified data and original data sort-merge join means to get result.