Which of the following is not an element of a relational database model?

A.
Relations, tuples, attributes and domains

B.
Data Manipulation Language (DML) on how the data will be accessed and manipulated

C.
Constraints to determine valid ranges and values

D.
Security structures called referential validation within tables

Explanation:
A relational database model uses attributes (columns) and tuples (rows) to contain and organize information.
The relational database model is the most widely used model today. It presents information in the form of
tables. A relational database is composed of two-dimensional tables, and each table contains unique rows,
columns, and cells (the intersection of a row and a column). Each cell contains only one data value that
represents a specific attribute value within a given tuple. These data entities are linked by relationships. The
relationships between the data entities provide the framework for organizing data. A primary key is a field that
links all the data within a record to a unique value.
Data manipulation language (DML) contains all the commands that enable a user to view, manipulate, and use
the database (view, add, modify, sort, and delete commands).
A constraint is usually associated with a table and is created with a CREATE CONSTRAINT or CREATE
ASSERTION SQL statement. They define certain properties that data in a database must comply with. They
can apply to a column, a whole table, more than one table or an entire schema.
Security structures called referential validation within tables are not an element of a relational database model.
Referential integrity is used to ensure all foreign keys reference primary keys. Referential validation is not a
security structure within a table.
Incorrect Answers:
A: Relations, tuples, attributes and domains are elements of a relational database model.
B: Data Manipulation Language (DML) is an element of a relational database model.
C: Constraints to determine valid ranges and values are an element of a relational database model.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, pp. 1171-1177