What is logical independence in data management?

Logical independence in data management refers to the ability to change the conceptual schema of a database without affecting the external views. This means that the way data is organized and structured at a higher level (conceptual schema) can be modified or updated, such as adding new fields or changing relationships between entities, without requiring changes to how that data is presented to users or applications (external views).

This concept is vital for maintaining flexibility in a database system, as it allows developers and administrators to adapt the database structure for evolving requirements or to optimize performance without disrupting the user experience or existing applications that rely on that data. Hence, logical independence enhances data management by allowing for changes at the conceptual level while keeping the user interfaces intact.

In contrast, the other options describe scenarios that are either incorrect or do not align with the definition of logical independence. Changing the physical schema affecting data refers to physical independence, while not being able to change any schema at all or requiring constant updates are not characteristics associated with logical independence. These distinctions clarify the importance of logical independence in data management practices.