After extracting data and transforming it into a usable format, the final step in the ETL workflow is loading it into a target system. This chapter examines the 'Load' stage, where the prepared data is moved to its destination, such as a data warehouse or database.

You will learn about:

• Selecting appropriate target systems.
• Common loading strategies, including full loads ($L_{full}$) and incremental updates ($L_{incremental}$).
• The significance of target schemas and mapping transformed data fields.
• Techniques for handling loading errors.
• Methods for post-load data validation.

Completing this stage successfully makes the processed data accessible for analysis and downstream applications.