Primary Key
An attribute whose value is unique across all occurrences of a relation.
Relational Database Model
Data represented as a set of related tables or RELATIONS
Relations
A named 2D table of data. Each relation consists of a set of named columns
and an arbitrary number of unamed rows
Well-Structured relation
A relation that contains a minimum amount of redundancy and allows users to
insert, modify, and delete rows, without error or inconsistencies.
Normalization
The process of converting complex data structures into simple, stable data
structures.
Functional Dependency
, A constraint between 2 attributes in which the value of one attribute is
determined by the value of another attribute
Second Normal Form
A relation in second normal form IF every nonprimary key attribute is
FUNCTIONALLY DEPENDENT on the whole primary key.
Third Normal Form
A relation in second normal form and has NO FUNCTIONAL
DEPENDENCIES between 2 or more nonprimary key attributes
Foreign Key
An attribute that appears as a nonprimary key attribute in ONE RELATION
and as a primary key in ANOTHER relation
Referential Integrity
Rule that states that either each foreign key value MUST MATCH a primary
key value in ANOTHER relation, or the foreign key must be null
Recursive Foreign Key
A foreign key in a relation that references the primary key values of that
SAME relation