In this session, you learnt the following:
- What a data warehouse is.
- The differences between a data warehouse and a transactional database.
- OLAP (Online Analytical Processing) systems are Subject-oriented, Integrated, Non-volatile and Time-variant.
- A data warehouse provides an integrated view of the entire organisation and the data is organised for carrying out analysis efficiently.
- Facts and dimensions and how to arrange them in order to design a data warehouse.
- Dimension tables act as metadata, which is data about data, and enhance the facts table to enhance the insights from the data.
- What a star schema is.
- The advantages of having a star schema in a database.
- The SETL process: Select, Extract, Transform and Load.
- The different types of constraints: Entity, Referential and Semantic constraints.
- ERDs and their constituents.