Theories and models
It is said that creating a database is more about art than it is about science. I tend to agree with this. However, a number of theories and rules have evolved over the last 40 years that are worth understanding before attempting to build a database for an Oracle Business Intelligence system.
From an overall design perspective, there are two scientific types of database:
- Transactional databases
- Reporting databases
A transactional database is designed for the input and update of data, usually in small, high volume changes to the data; whereas a reporting database is designed for fast access to data, which can be transformed into useful information for decision-making. The common name for a reporting database is the data warehouse (a phrase originally coined by Bill Inmon, the inventor of data warehousing).
The following diagram shows how tables in a transactional model are laid out. It shows a small extract of the system that will be used throughout this book, and is...
