Database Reference
In-Depth Information
A primary key is a candidate key that has been chosen to be
the
unique
identifier for an entity.
A program is a large, centrally organized initiative that contains multiple
projects. It has a start date and, if successful, no end date. Programs
can be very complex and require long-term modeling assignments.
Examples include a data warehouse and a customer relationship man-
agement system.
program
A project is a plan to complete a software development effort, often
defined by a set of deliverables with due dates. Examples include a sales
data mart, broker trading application, reservations system, and an en-
hancement to an existing application.
project
recursive rela-
tionship
A recursive relationship is a relationship between instances of the same
entity. For instance, one organization can report to another organization.
Relational
Database Man-
agement System
The Relational Database Management System represents the traditional
relational database invented by E. F. Codd at IBM in 1970 and first com-
mercially available in 1979 (which was Oracle) [Wikipedia].
A relational model (also called “relational data model”) captures how
the business works and contains business rules such as “A
Customer
must have at least one
Account
” or “A
Product
must have a
Product
Short Name
.”
relational model
Rules are captured on our data model through relationships. A relation-
ship is displayed as a line connecting two entities.
relationship
The process of understanding an existing application by starting with
its database and working up through the modeling levels until a concep-
tual data model is built.
reverse engin-
eer
secondary key
