Database

Database

The Relational Model and Normalization has 41 Questions

Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that:

A ? B.
A ? C.
A ? (B,C).
(B,C) ? A.
In a relation, the order of the rows matters.

True
False
The different classes of relations created by the technique for preventing modification anomalies are called:

normal forms.
referential integrity constraints.
functional dependencies.
None of the above is correct.
In a relation, the rows are sometimes called "records."

True
False
A relation is in this form if it is in BCNF and has no multivalued dependencies:

second normal form.
third normal form.
fourth normal form.
domain/key normal form.
A relation is a two-dimensional table.

True
False
Row is synonymous with the term:

record.
relation.
column.
field.
Any table that meets the definition of a relation is said to be in first normal form.

True
False
The primary key is selected from the:

composite keys.
determinants.
candidate keys.
foreign keys.
Given the functional dependency R ? (S,T) , then it is also true that R ? S.

True
False
Which of the following is a group of one or more attributes that uniquely identifies a row?

Key
Determinant
Tuple
Relation
A candidate key is a determinant that determines all the other columns is a relation.

True
False
When the values in one or more attributes being used as a foreign key must exist in another set of one or more attributes in another table, we have created a(n):

transitive dependency.
insertion anomaly.
referential integrity constraint.
normal form.
The only reason for the existence of relations is to store instances of functional dependencies.

True
False
A relation is considered a:

Column.
one-dimensional table.
two-dimensional table.
three-dimensional table.
A relation is in 5NF when multivalued dependencies are isolated in their own relation.

True
False
In the relational model, relationships between relations or tables are created by using:

composite keys.
determinants.
candidate keys.
foreign keys.
The functional dependency R ? S means that the value of S can be determined when we are given a value of R.

True
False
A functional dependency is a relationship between or among:

tables.
rows.
relations.
attributes.
In a relation, the columns are sometimes called "attributes."

True
False
Table is synonymous with the term:

record.
relation.
column.
field.
In a relation, the order of the columns does not matter.

True
False
Which of the following is not a restriction for a table to be a relation?

The cells of the table must contain a single value.
All of the entries in any column must be of the same kind.
The columns must be ordered.
No two rows in a table may be identical.
A functional dependency is a relationship between or among attributes.

True
False
For some relations, changing the data can have undesirable consequences called:

referential integrity constraints.
modification anomalies.
normal forms.
transitive dependencies.
A key is a group of one or more attributes that uniquely identifies a row.

True
False
A key:

must always be composed of two or more columns.
can only be one column.
identifies a row.
identifies a column.
Keys made up of two or more attributes are called composite keys.

True
False
An attribute is a(n):

column of a table.
two dimensional table.
row of a table.
key of a table.
Given the functional dependency R ? S , R is called the determinant.

True
False
A relation in this form is free of all modification anomalies.

First normal form
Second normal form
Third normal form
Domain/key normal form
Relations are categorized into normal forms according to the referential integrity constraints that they have.

True
False
If attributes A and B determine attribute C, then it is also true that:

A ? C.
B ? C.
(A,B) is a composite determinant.
C is a determinant.
A relation is in Boyce-Codd Normal Form (BCNF) if every determinant is a composite key.

True
False
A tuple is a(n):

column of a table.
two dimensional table.
row of a table.
key of a table.
A functional dependency is always an equation.

True
False
If attribute A determines both attributes B and C, then it is also true that:

A ? B.
B ? A.
C ? A.
(B,C) ? A.
A relation has cells that hold multi-value entries.

True
False
One solution to the multivalued dependency constraint problem is to:

split the relation into two relations, each with a single theme.
change the theme.
create a new theme.
add a composite key.
In a relation, the rows are sometimes called "fields."

True
False
A primary key is a composite key that was selected to be the main identifier for the relation.

True
False