Which of the following is NOT a characteristic of a flat-file database?

A flat-file database is characterized by its structure and design, which typically involves a single table containing all the data. This means that it organizes data in a straightforward manner where each record is represented as a single line in the file.

The premise of supporting multiple relationships does not apply to flat-file databases, as they are inherently limited to a single table structure without the capability to establish complex relationships between different sets of data. Instead, relational databases are designed to support multiple relationships through the use of multiple tables linked by keys.

In contrast, the other characteristics are indeed features of flat-file databases. They are simpler to manage because of their straightforward design, making them easier for smaller projects or applications where complexity is not necessary. Also, flat-file databases tend to have limitations in scalability, as they can become inefficient when managing large volumes of data or complex queries compared to other types of databases that are built to handle growth in data and relationships efficiently.