Database Reference
In-Depth Information
Clarification on Data Independence
Data independence is an important concept that needs further clarification: Data
independence is the immunity of application programs to changes in structure and
access strategy of data. It is necessary for the following reasons:
•
Different applications and users will need to have different logical
views (interpretation) of data.
•
The tuning of the system should not affect the application programs.
Physical data independence implies that the user's view is independent of physical
file organization, machine or storage medium. Logical data independence implies that
each user (or application program) can have his/her (its) own logical view and does not
need a global view of the database.
1.3 Advantages of a Database System
A database system brings a number of advantages to its end users as well as the company
that owns it. Some of the advantages are mentioned below:
•
Redundancy can be reduced.
•
Inconsistencies can be avoided.
•
Data can be shared.
•
Standards can be enforced.
•
Security restrictions can be applied.
•
Integrity can be maintained.
•
Conflicting requirements can be balanced.
•
Improved performance due to speed of processing, reduction in
paperwork, etc.
•
Maintenance and retrieval of data are very easy — no complicated
application program needed.
•
Is not solely dependent on the high level language (HLL)
programming for use.
•
Logical views of data stored can be easily created.
•
Record structures can change without any adverse effect on data
retrieval (due to data independence).
