What-If Query Processing Policy of Main-Memory OLAP System
Yan Zhang · 2010
A what-if analysis can provide a more meaningful information than classical OLAP(on-line analysis processing).Multi-Scenario hypothesis upon historical data needs efficient what-if data view support.Two novel algorithms of deltaMap and pre-merge,which can greatly improve the performance of delta table algorithm with set operations,are proposed.To analyze the performance of query re-writing algorithm and delta cube algorithm under different what-if update conditions,a global performance analysis and comparison are presented in the experiment section.This paper proposes a cost model for a what-if analysis processing engine,based on different algorithms with parameters such as application scenario,what-if update rate,complexity of what-if updates,memory storage policy,cardinality of query result set etc,that can be used as a practical framework in a what-if analysis system.