.

Just so, where is Oplog size in MongoDB?

To view the current size of the oplog, switch to the local database and run db. collection. stats() against the oplog.rs collection. stats() displays the oplog size as maxSize .

Beside above, can I use MongoDB locally? Using a local instance of MongoDB is a very simple process. We will use mongooseJS, the Node package for working with MongoDB. We will also give mongoose a database name to connect to (it doesn't need to be created since mongoose will create it for us). Here's some sample code to connect to a database in Node.

Herein, what is the use of journaling in MongoDB?

MongoDB uses an on-disk journal to guarantee write operations and provide crash resiliency. MongoDB also creates a journal for every write that includes the exact disk location and the bytes that changed in the write.

What is default database in MongoDB?

Default created database of MongoDB is 'db' present within the data folder. The command creates a new database if it doesn't exist, otherwise, it will return the existing database. you can run this command in mongo shell to create a new database. Your newly created database is not present in the list of Database.