extract, transform, load (ETL)
An ETL process is the data flow process into a data warehouse or related system. In this process, data is extracted from the source systems, transformed, integrated and written to the target system.
The ETL process (extract/transform/load) characterizes the three classic steps for filling a data warehouse:
- Extraction: data is loaded from one or more source systems into the ETL system.
- Transformation: The data is transformed in the ETL system. This can involve technical transformations, such as changing data types, as well as business transformations, such as calculations and aggregations.
- Load: The data is loaded from the ETL system into the data warehouse.
In modern ETL processes, a distinction is made between other tasks that are performed in an ETL process:
1. data cleansing (data cleansing)
3. historization
4. pre- aggregation
5. cube and datamart generation
7. email notification, etc.
8. logging and change tracking.