Storage Engines The storage engine is the component of the database that is responsible for managing how data is stored, both in memory and on disk. MongoDB supports multiple storage engines, as different engines perform better for specific workloads. Choosing the appropriate storage engine for your use case can significantly impact the performance of your applications.
Starting in version 4.2, MongoDB removes the deprecated MMAPv1 storage engine.
➤ WiredTiger Storage Engine (Default) WiredTiger is the default storage engine starting in MongoDB 3.2. It is well-suited for most workloads and is recommended for new deployments. WiredTiger provides a document-level concurrency model, checkpointing, and compression, among other features.
In MongoDB Enterprise, WiredTiger also supports Encryption at Rest. See Encrypted Storage Engine.
➤ In-Memory Storage Engine In-Memory Storage Engine is available in MongoDB Enterprise. Rather than storing documents on-disk, it retains them in-memory for more predictable data latencies.
原文 - Storage Engines