Chapter 3 Flashcards
What is a domain?
The set of possible values for this attribute.
What is functional dependence?
The relationship between two sets of attributes in a table. One can exist without the other, but not the other way around.
What is a composite key?
Process of combining two attributes to uniquely identify each row.
What is a superkey?
It is any key that uniquely identifies each row.
What is a candidate key?
It is a super key without any redundancies, a minimal super key.
What is a primary key?
Unique identifier for each row in a database table.
What is entity integrity?
A rule that ensures each row in a table has a primary key.
No duplicates or nulls are allowed.
What is referential integrity?
A rule that ensures data in one table connects to existing data in another table (foreign key).
No duplicates or nulls are allowed.
What is a foreign key?
An attribute that connects tables by referencing another table’s primary key.
What is a secondary key?
Any key used strictly for data retrieval purposes.
