State-space optimization of ETL workflows Alkis Simitsis, Panos Vassiliadis, and Timos K. Sellis   View Paper (PDF)   Return to October 2005, Volume 17, Issue 10 Abstract Extraction-transformation-loading (ETL) tools are pieces of software responsible for the extraction of data from several sources, their cleansing, customization, and insertion into a data warehouse. In this paper, we derive into the logical optimization of ETL processes, modeling it as a state-space search problem. We consider each ETL workflow as a state and fabricate the state space through a set of correct state transitions. Moreover, we provide an exhaustive and two heuristic algorithms toward the minimization of the execution cost of an ETL workflow. The heuristic algorithm with greedy characteristics significantly outperforms the other two algorithms for a large set of experimental cases. ©2006 Association for Computing Machinery