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