Processes:
- Extract: Data is extracted from various source systems, such as databases, APIs, or files. The data can come from relational databases, flat files, cloud applications, or other structured/unstructured sources.
- Transform: After extraction, data is transformed to ensure it meets the desired format and structure. This transformation can include cleaning, filtering, aggregating, enriching, and applying business rules to the data. This process often occurs in a staging area or an intermediate processing system.
- Load: Once transformed, the data is loaded into the target system, typically a data warehouse, where it can be used for analytics and reporting.
ETL is most commonly used when working with traditional data warehouses (on-premises or cloud-based) where transformation needs to be done before loading the data into the system.
See also: ETL vs ETL