Data Models Flashcards
What is data modeling?
It is the creation of a specific data model for a determined problem domain
What is a data model?
It is a simple representation of complex real-world data structures
What is a model?
It is an abstraction of a more complex real-world object or event
Why is data modeling important?
Facilitates communication
Gives various views of the database
Organizes data for various users
Provides an abstraction for the creation of good a database
What is an entity?
It is a person, place, thing, or event about which data will be collected and stored
What is an attribute?
It is a characteristic of an entity
What is a relationship?
It is the association among entities
What is a constraint?
It is a restriction placed on data
What are business rules?
They are brief, precise, and unambiguous descriptions of a policy, procedure, or principle within a specific organization
What are the sources of business rules?
Company managers
Policy makers
Department managers
Written documentation
Direct interviews with end users
What are the reasons for identifying and documenting business rules?
Standardize company’s view of data
Facilitate communications tool between users and designers
Assist designers
What are relationships?
They are bidirectional
What are entity name requirements?
Be descriptive of the objects in the business environment
Use terminology that is familiar to the users
What are attribute names?
They are required to be descriptive of the data represented by the attribute
What does proper naming do?
Facilitates communication between parties
Promotes self-documentation