Multi-Key File Organisation

In this part, we will introduce two basic file Organisation schemes that permit records to be accessed by more than one key field, therefore, allowing multiple access paths each having a dissimilar key. These are known as multi-key file Organisations. These file organisation methods are at the heart of database execution.

There are numerous methods that have been used to execute multi-key file Organisation. Most of these methods are based on building indexes to provide direct access by the key value. Two of the commonest methods for this Organisation are:

• Multi-list file Organisation
• Inverted file Organisation

Let us talk about these methods in more detail. But first let us talk about the need for the Multiple access paths.