The new Memory Optimized Index (MOI) feature in Couchbase Server 4.5 is designed to support demanding applications that require fast query performance and real-time data access, such as travel booking, leader boards, fraud detection, and interactive recommendations. MOI provides improved latency and throughput under heavy data mutations by utilizing lock-free processing, skiplist structure in-memory storage, forcing the index into memory storage, and regular snapshots persisted to disk for recovery. This feature is particularly useful for applications that require interactive access to data and can benefit from reduced query times and increased scalability. With MOI, Couchbase clusters can now scale data services linearly while also querying at high performance levels, making it an attractive solution for businesses seeking to improve their data processing capabilities.