Gr 11 4.3 – INTRODUCTION TO MULTI-TABLES

Question 1

Anomalies

Answer 1

Problems or errors that occur when you try to insert data,
delete data or update data.

Question 2

Composite keys

Answer 2

The combination of more than one field to uniquely identify
a record.

Question 3

Data independence

Answer 3

The same application can be used for data stored on
different media (physical independence), and the application
will not be affected when you add a table to a database or
create extra fields in existing tables (logical independence).

Question 4

Data integrity

Answer 4

The overall completeness, accuracy and consistency of data.
Data integrity is ensured when each record has its own
unique primary key and when a foreign key refers to an
existing record in another table.

Question 5

Data maintenance

Answer 5

Adding or deleting records, or updating data.

Question 6

Data redundancy

Answer 6

The unnecessary repetition of data.

Question 7

Data security

Answer 7

The protection of databases against unauthorised access by
users.

Question 8

ER

Answer 8

(ENTITY RELATIONSHIP) DIAGRAMS
Diagrams used to illustrate relationships between entities.

Question 9

Foreign keys

Answer 9

A field (not a primary key) that is used as a ‘link’ to a field in
another table (usually the primary key).

Question 10

Relational database

Answer 10

A database containing many tables linked together in
relationships.