Explain The Difference Between Physical And Logical Data Independence

1.	Explain The Difference Between Physical And Logical Data Independence?
Answer» Physical data independence is the ability to modify the physical scheme without MAKING it necessary to rewrite application PROGRAMS. Such modifications include changing from unblocked to blocked record storage, or from sequential to random ACCESS files. Logical data independence is the ability to modify the conceptual scheme without making it necessary to rewrite application programs. Such a MODIFICATION might be adding a field to a record; an application program’s view hides this change from the program.

Explain The Difference Between Physical And Logical Data Independence?

Answer»

Physical data independence is the ability to modify the physical scheme without MAKING it necessary to rewrite application PROGRAMS. Such modifications include changing from unblocked to blocked record storage, or from sequential to random ACCESS files.
Logical data independence is the ability to modify the conceptual scheme without making it necessary to rewrite application programs. Such a MODIFICATION might be adding a field to a record; an application program’s view hides this change from the program.

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Explain The Difference Between Physical And Logical Data Independence?

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