The document discusses database structure and types. It states that a database organizes and stores data in files made up of records containing fields. A flat file database uses a single table that becomes inefficient with large amounts of data. Relational databases improve on this by storing data across multiple linked tables using primary keys. The document also describes anomalies like insertion, update, and deletion that occur in flat file databases.

2. Database Structure
 A database is a system for organising and storing data
 Databases are made up of one or more files
 Files are a collection of records, and records are made up of fields.

3. Database Structure
 A database is a system for organising and storing data
 Databases are made up of one or more files
 Files are a collection of records, and records are made up of fields.

4. Database Structure
 Each column represents a field
 Each row represents a record

5. Flat File Database
 A flat-file database is a database structure which consists of only a single
table.
 While this is a simple way to store files, a flat-file system becomes
increasingly inefficient as more data is added.

6. Database Anomalies
Whilst the flat-file database might seem to be a good solution to begin with,
there are actually a number of problems which are linked with this approach.
These are known as anomalies.

7. Database Anomalies
Anomaly 1:
Mr O'Hara is a teacher in the English department and he teaches in English
Room 4. Add Mr O'Hara's details to the database.

8. Database Anomalies
Anomaly 1:
Mr O'Hara is a teacher in the English department and he teaches in English
Room 4. Add Mr O'Hara's details to the database.
This is known as an insertion anomaly.

9. Database Anomalies
Anomaly 2:
The art department is reorganising rooms and Miss Dewar is moving from Art
Room 3 to Art Room 1. Update the database to show this.

10. Database Anomalies
Anomaly 2:
The art department is reorganising rooms and Miss Dewar is moving from Art
Room 3 to Art Room 1. Update the database to show this.
This is known as an update anomaly.

11. Database Anomalies
Anomaly 3:
John McGinn has left school. His record should be deleted from the database.

12. Database Anomalies
Anomaly 3:
John McGinn has left school. His record should be deleted from the database.
This is known as a deletion anomaly.

13. Relational Databases
A better approach to database design is known as the Relational Database
Model. In the relational model, the data is stored in multiple tables or relations.
However, in this example we have lost the link between pupil and their tutor
teacher.

14. Relational Databases
We create linked tables by introducing keys.

15. Relational Databases
We create linked tables by introducing keys.