Which characteristic is typical of a NoSQL database?

The characteristic that is typical of a NoSQL database is its flexibility in data models that can accommodate unstructured data. This flexibility is crucial because NoSQL databases are designed to handle a wide variety of data types, including unstructured and semi-structured data. Unlike traditional relational databases that require a fixed schema, NoSQL databases such as document stores, key-value stores, and wide-column stores allow for more dynamic and adaptable data structures. This means that data can be stored in various formats without the need for prior definitions, making it easier to manage complex data and scale applications efficiently.

In addition to handling unstructured data, NoSQL databases typically allow for horizontal scaling, meaning they can grow by adding more nodes rather than requiring significant changes in structure or design. This ability makes them particularly useful in applications involving large volumes of diverse datasets, such as big data applications, real-time web applications, and any scenario where data types are likely to change frequently.

In contrast, the other options describe characteristics more aligned with traditional relational database systems, which emphasize structured schemas, relationships, data integrity, normalization, and the use of SQL for querying. These traits are not typical of NoSQL systems, which prioritize flexibility and scalability over strict adherence to predefined structures and relationships.