2c)

An existing relational database, developed in accordance with the three-schema architecture, is supporting several applications that share data. Some new requirements are identified by the database users that result in new applications being developed, as follows:

1. A new application requires a new table in the database and uses none of the existing tables.
2. A new application is required that uses exactly the same data already being used by an existing application. However, the performance requirements for the new application require the database to use new hardware so that data retrieval is more efficient.
3. A new application uses tables already in the database that are currently in use by different existing applications; no existing application uses all these tables.

For each of these applications requirements:

• i.state what changes would be required (if any) to each of the existing schemas in the three-schema architecture, and state why that change is required
• ii.state whether or not the required schema changes would affect any existing applications and justify your answer.