Extracting, Transforming, Loading: ETL

ETL stands for Extract, Transform, and Load. ETL programs periodically extract data from source systems, transforms the data into common format, and then loads the data into the target data store or warehouse. ETL process brings together and combines data from multiple source systems into a data warehouse, enabling all users to work off a single, integrated set of data.

• Extract The process of reading data from specified source database and extracting a desired subset of data.

• Transform The process of transforming the data in the required form so that it can be placed into another database. Transformation occurs by using rules or lookup tables or by combining with other data

• Load The process of writing/loading the data into the target database.