MongoDB

Projection is used to select only the necessary data. It does not select the whole data of a document.

The remove() method is used to remove a document from a collection.

The pretty() method is used to show the results in a formatted way.

The db.dropDatabse() command is used to drop a database.

To create a database, we can use the Database_Name command.

The sharded cluster has the following components:

Horizontal scaling divides the dataset and distributes data over multiple servers, or shards.

Vertical scaling adds more CPU and storage resources to increase capacity.

The oplog records all operations that modify the data in the replica set.

The createIndex() method is used to create an index.