Sunday, August 18, 2019

Data Independence

Data Independence

Data Independence

Data Independence is the capacity of DBMS Architecture to change the schema at one level. Of the DB system. Without having to change in schema at a next higher level.

There are 2 type of data independence

1) Logical data independence
2) Physical data independence

1) Logical data independence


It’s the capacity to change the conceptual schema without having to change the external schema or application program. Only the view definition and mappings head to be changed in DBMS. That support logical data independence.


2) Physical data independence


It is the capability to vary the internal schema while not having to vary the conceptual schema. Hence, the external schema need not to change as well.
Application program are set to show physical data independence. If they do not depend on physical schema.
Thus they need not to be re-write if the Physical Schema changes.


Next Topic ➧ Data Modeling in DBMS

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