Chapter 2

1. OLTP provides solutions for operational activities of a company, such as effective and safe data storage, transaction data reconstruction, updating of data, optimization of the access to the data, and concurrency control (Garcia-Molina, Ullman, & Widom, 1999).

2. Inmon (2005).

3. Garcia-Molina, Ullman, and Widom (2008).

4. See http://www.inmoncif.com/

5. Codd, Codd, and Salley (1993), p. 7.

6. This fact table is used here for purely illustrative purposes, as “Costs” represents a very high level of aggregation, which in practice does not exist at the level of a fact table.

7. This table with the dimension “Date” is used here for purely illustrative purposes, as the lowest level of representation of time at the level of a month does not exist in practice.

8. For the definition of a primary key, see Ullman and Widom (2007).

9. For the definition of a foreign key, see Ullman and Widom (2007).

10. This class of technological systems is built by means of database management systems, which ensure suitable security and cohesion of data processing (OLTP).

11. Todman (2001).

12. Kimball and Ross (2002).

13. All schemas are simplified and solely illustrative.