4. Types of distributed database (1)

There are three main options when putting together a distributed database.

1. Duplicated database at each location

With this system, a local copy of the entire database is kept at each location. As shown below.

This is often not practical for a number of reasons:

Disadvantages:

• Very heavy use of the network.
• Whole database may be huge requiring large storage requirement at each location
• Difficult to keep all copies in synchronisation
• It does not scale well as the database grows.
• Wasteful if only a small area of the database is needed by each branch

Advantages:

• If the database is fairly small, then this may be a practical solution.