what is data independence exactly? give an example
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There are two types of data independence
1. Logical data independence: The ability to change the
logical (conceptual) schema without changing the External
schema (User View) is called logical data independence. For
example, the addition or removal of new entities,
attributes, or relationships to the conceptual schema should
be possible without having to change existing external
schemas or having to rewrite existing application programs.
2 Physical data independence: The ability to change the
physical schema without changing the logical schema is
called physical data independence. For example, a change to
the internal schema, such as using different file
organization or storage structures, storage devices, or
indexing strategy, should be possible without having to
change the conceptual or external schemas.
Is This Answer Correct ? | 127 Yes | 11 No |
Answer / guneetinder singh
Data independence means when we bring out changes in lower
levels then upper level does not feel any affect.
i.e. changing internal level does not affect conceptual level.
Is This Answer Correct ? | 77 Yes | 10 No |
Answer / mohammad ikram
Physical data independence
- the capacity to change the internal schema without
having to change the conceptual (or external) schema
- internal schema may change to improve the performance
(e.g., creating additional access structure)
Is This Answer Correct ? | 17 Yes | 4 No |
Answer / noor alam
The separation of data descriptions from the application
programs (or user-interfaces) that uses the data is called
data independence.
Is This Answer Correct ? | 8 Yes | 3 No |
Answer / monika
Data independance:
It includes the isolation of data from application program.
There are 2 types of data independance:
1.Logical data independance:
The ability to change the conceptual schema without
altering the external schema or application programs.
2.Physical data independance:
It is ability to change the internal schema without
changing the conceptual or external schema.
Is This Answer Correct ? | 4 Yes | 4 No |
Answer / mohammad aquib
When the logical structure of database changes , application program are only minimally affected and requires very little modification ,it is called data independent
Is This Answer Correct ? | 0 Yes | 0 No |
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