MongoDB Interview Questions and Answers

Mention what are the different types of NoSQL databases?

There are four types of NoSQL database:

  • Document store NoSQL database
  • Graph base NoSQL database
  • Key value store NoSQL database
  • A column store NoSQL database

There are some other NoSQL databases such as Cassandra, CouchBD, Hybertable, Redis, Riak, Neo4j, HBASE, Couchbase, MemcouchDB, Voldemort, RevenDB and so on.

Explain why MongoDB is at best NoSQL database?

The MongoDB is the best NoSQL database because it is:

  • Easily Scalable
  • Document Oriented
  • High Performance
  • Rich Query Language
  • High Available

What do you understand by Namespace in MongoDB?

MongoDB store BSON objects in collections. The Namespace is a connection of the database name and the collection name.

Can journaling features be used to perform safe hot backups?

Yes.

Explain why profiler is used in MongoDB?

The MongoDB uses a database profiler to perform features of each operation against the database. You can also use  a profiler to find issues and write operations.

Explain – if you terminate an object attribute , is it deleted from the database?

Yes, it is. Terminate the attribute and then re-save () the object.

In which language MongoDB is written?

MongoDB is written and implemented in C++.

Does MongoDB need a more space of RAM?

No, a MongoDB can be run on small free space of (RAM) Random Access Memory.

Is MongoDB database having tables for storing records?

No, Instead of tables, MongoDB uses “Collection” to store data.

Compare MongoDB with CouchDB and CouchBase?

The MongoDB and CouchDB are both document oriented databases. In other words MongoDB and CouchDB are the best examples of open source NoSQL database. Besides both storing documents though, it turned out that they are not famous much in common. There is more difference between MongoDB and CouchDB in terms of implementation of their data-model, object store, interface, and replication techniques and so on.