Extracting, Transforming, and 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 processes bring together and combine data from multiple source systems into a data warehouse or other target database, 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 into 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 or loading the data into the target database.