What is ETL?
Extract, Transform and Load (ETL) is a process that involves
- extracting data from outside sources, transforming
- transforming it to fit business needs (which can include quality levels), and ultimately
- loading it into the end target, i.e. the data warehouse loading
It is a process to extract data, mostly from different types of system, transform it into a structure that's more appropriate for reporting and analysis and finally load it into the database. The term ETL can in fact refer to a process that loads any database. ETL can also be used for the integration with legacy systems. Usually ETL implementations store an audit trail on positive and negative process runs. This process also covers data profiling, data quality control, monitoring and cleansing, real-time and on-time data integrationin a service oriented architecture, and metadata management.