1Z0-006 Relational Data Model 3

Question 1

Which relational model concept states that every row in a table must be uniquely identifiable?

Accepted Answer

Entity integrity

Answer

Entity integrity requires that every table has a primary key and that no primary key column contains a NULL value.

Question 2

A FOREIGN KEY constraint with ON DELETE SET NULL means that when a parent row is deleted:

Accepted Answer

Child foreign key columns are set to NULL

Answer

ON DELETE SET NULL sets the foreign key column in child rows to NULL when the referenced parent row is deleted.

Question 3

Third Normal Form (3NF) eliminates which type of dependency?

Accepted Answer

Transitive dependencies

Answer

3NF removes transitive dependencies, where a non-key attribute depends on another non-key attribute rather than directly on the primary key.

Question 4

In Oracle, which pseudocolumn uniquely identifies each row's physical location in the database?

Accepted Answer

ROWID

Answer

ROWID is a pseudocolumn that provides the unique physical address of each row, identifying its exact storage location.

Question 5

Which relational operation returns only rows that appear in both of two query result sets?

Accepted Answer

INTERSECT

Answer

INTERSECT returns only the rows that are common to both result sets, eliminating rows that appear in only one.

(1Z0-006) Oracle Database Foundations Associate Practice Test