ETL

ETL Process: ETL is the Data Warehouse acquisition processes of Extracting, Transforming and Loading data from source systems into the data warehouse.

This requires an understanding of the business rules, the logical and the physical data models and also involves getting the data from the source and populating it into the target.

ETL-concepts

• Extraction

• Transformation

• Loading

• Slowly Changing Dimension –Classification

TYPE I

TYPE II

TYPE III

• Slowly Changing Dimension implementation-types

• Extraction types

• Data transformation

• Types of Data warehouse Loading

• Types of Data Warehouse Updates

• ETL - Approach in a nutshell