The leading NoSQL document database, emphasizing flexible schema and developer productivity. 2025 Relevance: Very high. MongoDB remains a dominant force in the document database space, with its Atlas cloud offering being particularly popular. Its flexible schema and rich query language make it a go-to for many modern applications.
CouchDB (Document): Another document database, focusing on eventual consistency, offline capabilities, and peer-to-peer replication. 2025 Relevance: Moderate (niche). Still active and valued for specific use sri lanka phone number list cases (e.g., mobile sync, offline-first apps), but its general adoption is smaller than MongoDB.
Neo4j (Graph): The pioneering and leading graph database, essential for highly connected data. 2025 Relevance: Very high. , have seen increasing adoption for use cases like fraud detection, recommendation engines, and knowledge graphs.
Redis (Key-Value/Data Structure Store): A blazing-fast, in-memory data structure store, widely used for caching, session management, and real-time operations. 2025 Relevance: Extremely high. Redis is indispensable for high-performance use cases and microservices architectures. Its versatility and speed ensure its continued dominance.