Yet it can be hard to appreciate why the ETL system is so complex and resource-intensive.Įveryone understands the three letters: You get the data out of its original source location (E), you do something to it (T), and then you load it (L) into a final set of tables for the business users to query. Developing the ETL system is challenging because so many outside constraints put pressure on its design: the business requirements, source data realities, budget, processing windows, and skill sets of the available staff. The extract, transformation, and load (ETL) system consumes a disproportionate share of the time and effort required to build a data warehouse and business intelligence (DW/BI) environment.
