Which of the following best defines a distributed database in terms of its logical and physical organization across multiple networked locations?

Introduction / Context:
This question focuses on the fundamental definition of a distributed database. In distributed database systems, the key idea is that users experience a single logical database, even though the data may be stored at different physical locations connected by a network. Understanding this distinction between logical unity and physical distribution is essential for recognizing what qualifies as a distributed database versus a simple collection of files or independent databases.

Given Data / Assumptions:

The term distributed database is being defined in the context of database management systems.
Logical database refers to a unified schema and view of data from the user perspective.
Physical locations can be separate sites or servers connected via a network.
Some options describe loose collections of files rather than integrated databases.
Other options limit the database to a single location, which contradicts distribution.

Concept / Approach:
In a distributed database, data is stored at multiple physical sites, yet the DBMS software provides a unified logical view. Users query the database as though it were a single system, while the DBMS handles where and how the data is actually stored and retrieved. This distinguishes a true distributed database from a mere collection of files or independent databases. The presence of a network that interconnects the sites is also essential. Therefore, the correct answer must mention both single logical database and spread across multiple locations interconnected by a network.

Step-by-Step Solution:
Step 1: Identify that a proper definition of a distributed database requires logical unity with physical distribution.Step 2: Examine the option that explicitly mentions a single logical database spread across multiple locations connected by a network.Step 3: Note that options describing loose collections of files do not guarantee an integrated schema or unified access.Step 4: Reject options that limit the database to a single location, since this contradicts the notion of distribution.Step 5: Confirm that the option describing a single logical database physically spread across sites fits the standard textbook definition.

Verification / Alternative check:
Standard definitions in database textbooks and vendor documentation describe a distributed database as a collection of multiple, logically interrelated databases distributed over a computer network. The user sees the system as one integrated database, while the DBMS manages the complexity of where data resides. This aligns with the option that emphasizes a single logical database spread across multiple locations interconnected by a network. The other options either omit the idea of logical unity or ignore the requirement of physical distribution, which confirms the correctness of the chosen answer.

Why Other Options Are Wrong:
A loose collection of files at multiple locations may be distributed in a storage sense but lacks the logical integration and schema that characterize a distributed database. A single logical database limited to one location is a centralized database, not a distributed one. A loose collection of files at a single location does not involve distribution or integrated management. A set of independent spreadsheets shared by email does not form a managed distributed database either, as there is no integrated DBMS, schema, or network based coordination.

Common Pitfalls:
Students sometimes equate any data stored at multiple locations with a distributed database, forgetting the importance of logical integration and DBMS support. Another pitfall is to think only in terms of physical storage and ignore the user perspective. Remember that a distributed database must provide a unified logical view while managing physically distributed data through a network. Keeping both aspects in mind helps distinguish a true distributed database from informal data sharing methods or simple file replication.

Final Answer:
The correct definition is that a distributed database is a single logical database that is physically spread across multiple locations and interconnected by a network.