Which are the storage engines used by MongoDB?

MMAPv1 and WiredTiger are two storage engine used by MongoDB.

As of my last knowledge update in January 2022, MongoDB supports multiple storage engines, but the default storage engine has changed over the course of its versions. As of MongoDB 4.0, the WiredTiger storage engine became the default. WiredTiger is known for its performance, scalability, and support for features such as document-level concurrency control.

Historically, MongoDB has also supported the MMAPv1 storage engine, but it was deprecated in MongoDB 4.0. Therefore, for modern versions of MongoDB, WiredTiger is the primary storage engine.

Please note that MongoDB evolves over time, and it’s always a good idea to check the official MongoDB documentation for the latest and most accurate information regarding storage engines and their support in the version you are using.