Relational Model Flashcards
A relational database consists of
a collection of tables each with a unique name
Terminology: Relation
same as table
Terminology: Tuple (or Record)
same as row or record
a record is a group of related attributes
identifiable by its primary key (or candidate key)
Terminology: Attribute (fields or columns)
same as column or field, a field is used to store an individual item of data
In relational database, no two rows with same values in all ________ positions
column
All values within a column in a relation have the _______ type
same;
simple type only
no complex values such as sets or other rows
Candidate Key
candidate key is an attribute or combination of attributes that uniquely identifies rows in a table
Primary Key
there can be more than one candidate from which the primary key is chosen
foreign key
an attribute or combination of attributes that match attribute(s) in another table