Information independence, more commonly known as data independence, is a core concept in database systems that allows for the modification of the database schema at one level without altering the schema at a higher level. This principle is a primary goal of the three-schema architecture. It enables changes to the logical or physical organization of data—such as adding a new field, splitting a table, or changing storage structures—without requiring changes to the application programs or user views that rely on that data. This separation significantly reduces maintenance costs and improves system flexibility.

A. An ability to change database type is a system migration or re-architecture effort, not the definition of data independence within a system.

B. An ability to make changes to existing queries is an application development task; data independence aims to protect queries from underlying data changes.

C. An ability to interchange databases relates to interoperability or migration, not the internal schema independence of a single database system.

---

1. Elmasri, R., & Navathe, S. B. (2017). Fundamentals of Database Systems (7th ed.). Pearson. In Chapter 2, Section 2.2, "The Three-Schema Architecture and Data Independence," the text defines logical data independence as "the capacity to change the conceptual schema without having to change the external schemas and their associated application programs" and physical data independence as "the capacity to change the internal schema without having to change the conceptual schema." This directly supports the idea of changing the data's organization.

2. Silberschatz, A., Korth, H. F., & Sudarshan, S. (2020). Database System Concepts (7th ed.). McGraw-Hill. In Chapter 1, Section 1.9, "Data Independence," it is stated: "The ability to modify a schema definition in one level without affecting a schema definition in the next higher level is called data independence." This confirms that the concept is about changing the schema (data organization).

3. Ramakrishnan, R., & Gehrke, J. (2003). Database Management Systems (3rd ed.). McGraw-Hill. In Chapter 1, Section 1.5.2, "Data Independence," the authors explain that data independence is a key advantage of a DBMS, allowing changes to the "conceptual schema... or the physical schema" without impacting applications. This aligns with changing the data's organization.