A Database Management System (DBMS) supports data independence by allowing changes to lower-level schemas without affecting higher-level schemas or application programs. When a lower-level schema changes, only the mappings between it and higher schemas need updating. Higher schemas remain unchanged, so applications referring to external schemas do not require modification.

2. enterprise.
Database Management System (DBMS)

24. When a schema at a lower level is changed,
• only the mappings between this schema and higher-level schemas
need to be changed in a DBMS that fully supports data independence.
• The higher-level schemas themselves are unchanged.
• Hence, the application programs need not be changed since they refer
to the external schemas.

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