Which NoSQL category is best suited for storing documents with nested data and flexible schemas?

• A. Key-Value
• B. Graph
• C. Column-Family
• D. Document

Answer: (D)

Document-oriented databases are built to store data as self-contained documents that can include nested structures like objects and arrays. Because there’s no fixed schema, each document can have a different shape, letting you evolve the data model over time and easily represent complex, hierarchical data. This makes them ideal for storing nested data such as a user profile with embedded addresses, preferences, and a list of orders, all retrieved in a single document and indexed on fields inside the document. In contrast, key-value stores focus on simple lookups, column-family stores organize data in rigid rows and columns, and graph databases emphasize relationships, so they don’t align as naturally with flexible, nested documents.