Is Full-Text Search in MongoDB based on Lucene?
Yes for MongoDB Atlas. see https://www.mongodb.com/blog/post/full-text-search-and-auto-scaling-coming-to-mongodb-atlas
Atlas Search (previously known as Atlas Full-Text Search) builds on Apache Lucene. There have been several updates since the original announcement referenced by @Omid, but one important change is that this feature is now available across all cluster tiers running MongoDB 4.2 (originally an M30 or above cluster was required).
There is also a Text Search feature available in the core MongoDB server since MongoDB 2.4. This feature supports more basic text search options and is not based on Lucene.
- Is Atlas Search available on non-cloud MongoDB?
- Why are there two different text search types for MongoDB (Atlas Search, Text Search). Which one is preferable?
- Can both of the text search types index data that are spread across different shards?
Atlas Search is currently not available on-prem. There is a relevant feature request you can watch and upvote: Atlas Search: support on-prem installations.
Atlas Search is a cloud-first initiative which provides more comprehensive search features for MongoDB Atlas users without any additional installation & management requirements. If you are a MongoDB Atlas user with advanced search requirements (and a MongoDB 4.2+ cluster), I would consider using Atlas Search.
However, Atlas Search does add some resource overhead because there are additional processes and storage requirements for the Lucene integration. See: Atlas Search Performance Considerations.
If you are not using Atlas (or have more basic text search requirements) you can use standard Text Search.
Yes, both of these text search indexes support sharded clusters.