What is data independence in DBMS

Data independence

With knowledge of the three-scheme architecture, the concept of data independence can be explained in such a way that a higher level of this data architecture is immune to changes at the next lower level.

Physical independence:
The logical scheme can therefore remain unchanged if, for example, the storage location or the storage form of individual data changes for reasons of optimization or reorganization.
Logical independence:
Likewise, with (most) changes to the logical schema, the external schemas can continue to exist unchanged. This is particularly desirable because it means that application programs do not have to be modified or recompiled.

Example of physical and logical independence

If, for example, in a geomatic engineering office with different departments (official surveying, line cadastre, etc.) the data from the GIS database used has to be ported to a new database server for whatever reason, this must not have any effect on the logical schema of the database .
If the logical scheme is changed again, the different user groups of the geomatic engineering office must be able to continue working with the data in the database without restrictions, although they have different user views of the data.