Database design is an art. Our world is based on a combination of different PROCESSES (often called as business processes) and many RELATIONSHIPS between OBJECTS. When you want to create a "real life" information system you have to put into account a lot of different dependencies between people, companies, business events, your boss demands and even secoligy. Such dependencies are known as BUSINESS RULES in database theory. |
When you start your database design, you try to determine existing PROCESSES and ENTITIES in you information field. At the biginning it seems to be very easy. Then you need to investigate dependencies on different entities; their reaction on events; you recognize that your objects has different attributes and some of this attributes use the same data types in different objects. This is a basis for DOMAINS. It is realy complicated and often you need to go a few steps back in your work... Large and complicated systems can be more easely designed with specials tools.
Detailed description is given on the other pages; links to them you can see on the left. ERWin is the famous tool for entity-relationship diagrams design; with the help of BPWin you can dipict business processes; SQL programmers will find the next two products very useful; TESTBytes helps you to test your system - it generates a large amount of sample data so you can use it immediately instead of days or weeks which you need to collect data in real time. ERWin BPWin SQL-Compass SQL-Station TESTBytes