Physical Database Design Issues

The database design includes the process of logical design with the use of E-R diagram, normalisation, etc., followed by the physical design.

The Key issues in the Physical Database Design are:

• The use of physical database design is to alter the logical description of data into the technical specifications for retrieving and storing data for the DBMS.
• The aim is to create a design for storing data that will give adequate performance and make sure database integrity, recoverability and security.

Some of the basic inputs needed for Physical Database Design are:

• Normalised relations
• Attribute definitions
• Data usage: retrieved, entered, deleted, updated
• Requirements for security, recovery, backup, retention, integrity
• DBMS characteristics.
• Performance criterion such as response time necessity with respect to volume estimates.

Though, for this type of data some of the Physical Database Design Decisions that are to be taken are:

• Modifying the logical design.
• Optimising attribute data types.
• Specifying the file Organisation.
• Choosing indexes.