Document Store

A document store is a NoSQL database that stores data as semi-structured documents - typically JSON or BSON objects. Each document can have its own structure with nested objects and arrays, without requiring all documents in a collection to share the same schema.

Document stores are a natural fit for API response data. A property listing returned by a real estate API is already a JSON object with nested fields (location, photos, agent details) - it can be inserted directly into MongoDB or Firestore without transformation to a flat relational schema.

The flexibility of document stores has trade-offs: queries across nested fields can be slower than SQL queries, and the absence of enforced schemas means data inconsistency can creep in without application-layer validation. They are best suited for storing heterogeneous records where schema flexibility is more valuable than strict consistency.