Which is a valid rule for Key-Value pairs?

Which is a valid rule for Key-Value pairs?

• A. Contain a serialized JSON string, Must be unique within an object, Can't be an object or an array
• B. Keys can be any primitive type
• C. Pairs can include nested objects
• D. They must reside in a fixed schema table

Answer: (A)

In a key-value setup, the rule focuses on keeping data simple and uniformly retrievable. Storing the value as a serialized JSON string ensures the value is always a single, transportable string regardless of its original structure. Keys must be unique within the container so every key maps to one specific value, preventing ambiguity. And prohibiting direct objects or arrays means you’d serialize complex data before storage, keeping the storage format consistent and easy to query by key. That’s why this option is the best fit: it enforces a consistent, simple storage format (serialized JSON strings), guarantees one value per key (uniqueness), and avoids storing complex types directly. The other ideas don’t align with common KV-store rules: keys aren’t freely any primitive type (they’re typically strings), you can’t rely on nested objects being stored as-is, and many KV models aren’t tied to a fixed schema table.

In a key-value setup, the rule focuses on keeping data simple and uniformly retrievable. Storing the value as a serialized JSON string ensures the value is always a single, transportable string regardless of its original structure. Keys must be unique within the container so every key maps to one specific value, preventing ambiguity. And prohibiting direct objects or arrays means you’d serialize complex data before storage, keeping the storage format consistent and easy to query by key.

That’s why this option is the best fit: it enforces a consistent, simple storage format (serialized JSON strings), guarantees one value per key (uniqueness), and avoids storing complex types directly. The other ideas don’t align with common KV-store rules: keys aren’t freely any primitive type (they’re typically strings), you can’t rely on nested objects being stored as-is, and many KV models aren’t tied to a fixed schema table.