4.3- Intro to Multi-Tables

Question 1

Anomalies

Answer 1

Problems or errors that occur when you try to insert, delete 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 an consistency of data. Data integrity ensured when each record had its own unique primary key and when a foreign key refers to an existing key in another table

Question 5

Data maintenance

Answer 5

Adding or deleting records, or updating data

Question 6

Data redundancy

Answer 6

Unnecessary repetition of data

Question 7

Data security

Answer 7

The protection of databases against unauthorised access by users

Question 8

ER diagrams

Answer 8

Entity Relationship Diagrams: diagrams used to illustrate relationships between entities

Question 9

Foreign keys

Answer 9

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

Question 10

Relational database

Answer 10

Database containing many tables linked together in relationships