Couchbase
An optimised version of MongoDB, data is written into memory and then disk.
Query language is using standard SQL to convert to JSON. Unlike MongoDB which use its own proprietary query language
| Feature | Couchbase | MongoDB |
|---|---|---|
| Architecture | Memory-First: Data is written to RAM first, then disk. | Disk-First: Relies on the OS file cache. |
| Scaling | Masterless: All nodes can handle reads and writes. | Primary-Secondary: Only one node handles writes. |
| Querying | SQL++ (N1QL): Standard SQL on JSON. | MQL: Proprietary JSON-based query language. |
| Caching | Built-in: No need for a separate Redis. | Usually requires an external cache for speed. |