FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -When you can change the internal model without affecting the conceptual model, you have logical independence. However, the internal model is still hardware-independent because it is unaffected by the choice of the computer on which the software is installed.

Detailed explanation-2: -Physical data independence is the ability to modify the physical schema without causing application programs to be rewritten. Modifications at the physical level are occasionally necessary to improve performance.

Detailed explanation-3: -Physical data independence is concerned mainly with how a set of data/ info gets stored in a given system. Logical data independence is concerned mainly with the changing definition of the data in a system or its structure as a whole.

Detailed explanation-4: -Examples of changes under Physical Data Independence Switching to different data structures. Changing the access method. Modifying indexes. Changes to compression techniques or hashing algorithms.