6202 quiz
In a relational database, a relation corresponds to:
A specific grouping of entities
Attribute values are drawn from a
Domain
Tuple is a synonym for attribute
FALSE (Row or tuple)////(Attribute or column)
A row instance is a specific set of rows
False
Every Super key is a Candidate Key
False
Rows are relation instances
False
The terms relation and row can be used interchangeably
False
Entity integrity requires that if there are different entity types in a relation that must be clearly marked
False (pK is not null)
Closure, in the relational model, says that all rows in a table must be the same kind of thing
False（closure means well formed created well formed）
Which is not an integrity constraint of the relational data model
Semantic Integrity
. Foreign keys must be minimal
True
A Tuple is a Row in a Table
True
A foreign key in one table must be a primary key in another table
True
A tuple and a relation are the same thing
True
Every Primary Key is a Candidate Key
True
Every Candidate Key is a Super Key
True
Every Foreign Key is a Primary Key, possibly for a different relation
True
Every Primary Key is a Super Key
True
More than one attribute can be defined on the same domain
True
Primary keys must be unique
True
Relations correspond to a specific grouping of entities
True
The cardinality of a relation is the number of tuples it contains
True
The collection of rows in a table correspond to a relation instance
True
The degree of a relation is the number of attributes it contains
True
The terms relation and table can be used interchangeably
True
When a key contains more than one attribute we call it a composite key
True
An attribute or set of attributes that uniquely identifies tuples in a relation is a
a super key
A(n) ____________ is a named column of a relation
attribue
If one candidate key has 3 attributes while another has 4, minimality requires us to give preference to the 3 attribute candidate key
false
Relation is to row as row is to column
false
Relations correspond to a specific set of entities
false
The degree of a relation is the number of tuples it contains:
false
The terms relation and row can be used interchangeably
false