DATA INDEPENDENCE

DATA INDEPENDENCE -: Data independence is define to as capacity to change the schema at one level of the database without having to change schema at next level of the database. It can be classified into two ways-;
1-logical independence
2-physical independence


Logical data independence-:Logical independence is define  as capacity to change  the logical schema without having to change external schema or application program .we may changes the conceptual schema to expand the database to change constraints or reduce the database .Only view information and mapping need be changed in DBMS that supported

Physical data independence -:physical data independence is define as capacity to change the internal schema without having to change conceptual schema .therefore external schema need to be changed
as well.