MongoDB Interview Questions

MongoDB supports following CRUD operations: Create Read Update Delete

By default, the_id collection is created for every collection by MongoDB.

A replica can be specified as a group of mongo instances that host the same data set. In a replica set, one node is primary, and another is secondary. All data is replicated from primary to secondary nodes.

MongoDB uses BSON to represent document structures.

Namespace is a concatenation of the database name and the collection name. Collection, in which MongoDB stores BSON objects.

In MongoDB, primary nodes are the node that can accept write. These are also known as master nodes. The replication in MongoDB is single master so, only one node can accept write operations at a time. Secondary nodes are known as slave nodes. These are read only nodes that replicate from the primary.

Yes. If you remove a document from database, MongoDB will remove it from disk too.

Yes.

MongoDB is a document oriented DBMS

MongoDB doesn’t follow file system fragmentation and pre allocates data files to reserve space while setting up the server. That’s why MongoDB data files are large in size.