ISRO CSE 2018 | Question: 53

Question

Immunity of the external schemas (or application programs) to changes in the conceptual scheme is referred to as:

1. Physical Data Independence
2. Logical Data Independence
3. Both (a) and (b)
4. None of the above

Comments

Option B.

Logical data independence: Refers to immunity of external schemas to changes in conceptual schema. Conceptual schema changes (e.g. addition/removal of entities). Should not require changes to external schema or rewrites of application programs.

Physical data independence: Refers to immunity of conceptual schema to changes in the internal schema. Internal schema changes (e.g. using different file organizations, storage structures/devices). Should not require change to conceptual or external schemas.

Source: https://www.tutorialspoint.com/dbms/dbms_data_independence.htm

https://quizlet.com/86871871/dbmsprelim-flash-cards/

Answer 1

Immunity here means if we make certain changes in the one level of database design it will not affect the other part of database design.

Physical data independence:- if we make any change in the physical storage of schema that it will not affect our logical schema/ conceptual schema like relation table.

Logical data independence:- if we make any change in the conceptual schema it will not affect external schema or end software using this database.

SO answer B.

https://www.tutorialspoint.com/dbms/dbms_data_independence.htm