The Data Warehouse ETL ToolkitThe single most authoritative guide on the most difficult phase of building a data warehouse The extract, transform, and load (ETL) phase of the data warehouse development life cycle is far and away the most difficult, time consuming, and labor intensive phase of building a data warehouse. Done right, companies can maximize their use of data storage; if not, they can end up wasting millions of dollars storing obsolete and rarely used data. Bestselling