NoSQL Interview Questions- With Simple Answers

NoSQL Interview Questions

This set of NoSQL interview questions was created by industry experts to help you breeze through your NoSQL interview. There is a collection of the most commonly asked NoSQL interview questions that are typically asked in job interviews that need this ability in this blog. It may be tough to prepare for a NoSQL interview; but, by reading through typical questions, you can have a good sense of what the interviewer might ask.

The way NoSQL operates is the topic of most NoSQL interview questions. Only the most basic questions about what it is and what services it performs will be asked. But, remembering how to answer a question isn’t the most important thing. Being confident in the way you speak is key to helping you get one step closer to passing that interview.

NoSQL Interview Questions With Sample Answers

What exactly is NoSQL?

NoSQL refers to a group of database systems that were created in response to an increase in the amount of data being saved about goods, people, and objects. The number of times this data is accessed, as well as the speed and processing requirements. Relational databases, on the other hand, were not meant to handle the scale and agility issues that current applications confront, nor were they designed to make use of today’s low-cost computation power.

What distinguishes NoSQL from other databases?

NoSQL databases are more scalable and give greater performance than relational databases, and its data format tackles numerous difficulties that the relational model is not meant to address:

  • Semi-structured, structured, and unstructured data in large quantities
  • Rapid iteration, agile sprints, and frequent code pushes are all part of the process.
  • Easy-to-use and versatile object-oriented programming
  • Instead of costly, monolithic architecture, use efficient, scale-out architecture.

State the differences between NoSQL and MySQL databases.

NoSQL databases are quickly becoming a key part of the database landscape, and with their unique set of benefits, they have the potential to be a game-changer in the industry. However, NoSQL isn’t ready yet, and industry experts should proceed with care. This is due to the fact that it lacks the maturity that SQL databases such as MySQL provide.

If your application isn’t like Google, Facebook, Yahoo, or Wikipedia, you should contemplate adopting NoSQL and stay with MySQL alternatively. Not only is there a significant skills gap in the NoSQL field, but there are also concerns like analytics, performance reporting, and migration to consider.

What is a NoSQL database in Oracle?

Oracle NoSQL Database is a key-value database that is spread over several servers. It’s made to store data in a highly reliable, scalable, and accessible manner over a customizable collection of storage nodes. Data is saved as key-value pairs that are written to certain storage nodes based on the main key’s hashed value. To guarantee high availability, quick failover in the case of a node loss, and efficient load balancing of requests, storage nodes are duplicated.

To read and write data, customer apps employ an easy-to-use Java/C API. Oracle NoSQL Driver establishes a connection with the client application, allowing access to the data via the required key’s suitable storage node. For convenient cluster management, a web-based console, as well as a command-line interface, is provided.

When is it better to utilize a NoSQL database over a relational database?

ACID is enforced by a relational database. As a result, you’ll have transaction-oriented data stores that are schema-based. It’s been tested and shown to work in 99 percent of real-world scenarios. Relational databases allow you to accomplish almost anything. When it comes to huge high-availability data storage, however, there are performance and scale limits.

Google and Amazon, for example, have massive data centers with terabytes of data. Due to the extreme blocking/schema/transaction characteristics of the RDBMS, querying and inserting are not performant in these circumstances. That is why, for huge performance and scalability, they have developed their own databases (really, key-value stores). The concept of NoSQL databases has been around for a long time, although the name is relatively new. Object, graph, column, document databases, and XML, are examples of these types of databases.

What are some of the benefits and drawbacks of NoSQL?

Given below are some advantages and disadvantages of NoSQL:

Advantages – 

  • The database of NoSQL may be extended to the defined limit using the new node ideas. This is an extra benefit of low-cost commodity hardware.
  • NoSQL databases are used to store enormous amounts of data. The notion of NoSQL is used in big data and newly posted user evaluations.
  • The database of NoSQL does not require any expensive administration.
  • Instead of investing money in complex systems, NoSQL may be deployed for a low cost.

Disadvantages – 

  • Though NoSQL is a new database storage technique, there are many other systems on the market that are already industry leaders.
  • The previously developed systems provide round-the-clock support, while the NoSQL support system is significantly less.
  • Because NoSQL is a new technology, it does not support the system’s existing commands.

What is the memory budget for a NoSQL database management system?

The replication node is the node that handles the data in the NoSQL database storage. It is also the memory’s biggest user. In terms of speed, the size of the java heap and the cache utilized by the replication node are critical. By default, NoSQL calculates these two parameters in terms of the amount of RAM accessible to the storage node. It is suggested that a storage node’s available memory be specified. If the storage node supports more than one replication node, the RAM will be equally distributed among all RNs.

What are the advantages and disadvantages of using a graph database with a NoSQL database?

The following are the advantages and disadvantages of graph databases which are a form of NoSQL database:

Benefits of the database – 

  • these are specifically designed for networking applications. A good example is a social networking site.
  • They’re also ideal for use in an object-oriented programming environment.

Cons of utilizing graph databases –

  • Because graph databases have a high degree of connectivity between notes, they are not ideal for network segmentation. 
  • Graph databases don’t scale well and NoSQL databases either.

List the many types of NoSQL data stores

The four types of no SQL data storage are commonly accessible or divided into four categories. They are as follows:

  • Key-value store – A key-value store is a basic data storage key system that uses a key to access various values.
  • Column family store – It’s a sparse metric system with column family storage. The keys are columns and rows.
  • Graph store – The graph store is utilized for dealing with situations that need a lot of relationships.
  • Document store – document stores are used to store hierarchical data structures in the database directly.

What exactly do you mean when you say “eventual consistency” about NoSQL databases?

NoSQL, eventual consistency implies that the system is left in a consistent state after all of the service logic has been completed. This idea is utilized in distributed systems to achieve high availability. It ensures that if no new changes I made to a particular item, all access to that item will ultimately return the last modified value. It is expressed in terms of BASE and RDMS, which are also known as ACID characteristics in NoSQL

Client applications may now rely on eventual consistency thanks to no SQL databases. Mongo DB and Cassandra are two NoSQL databases that are eventually consistent in various start-ups.

In NoSQL, what do you mean by “Polyglot persistence”?

It is advisable to use several data storage systems when saving data so that the system can store a variety of data in the future. We don’t want to take a chance on a single data storage system, therefore this is a simple option. Polyglot persistence is the name given to this sort of storage in NoSQL.

Explain the distinctions between NoSQL and RDBMS.

The following are some of the distinctions between NoSQL and RDBMS –

  • In terms of data format, no SQL does not adhere to any particular order. When it comes to the format of its data, RDBMS is more ordered and systematic.
  • In terms of scalability, NoSQL is far superior and more scalable. I DBMS, on the other hand, is average and less scalable than NoSQL.
  • Since NoSQL does not include a joint clause, it is restricted in terms of data querying. I DBMS, on the other hand, can imply querying since it uses the structured query language.


This article on NoSQL interview questions aims to help you understand the essential concepts of an OSQL to prepare for an interview. For your convenience, all of the main NoSQL questions are covered in-depth with examples to help you better understand each question.


What is an example of NoSQL?

Big data and real-time web apps both employ NoSQL. Every day, businesses like Twitter, Google, and Facebook, for example, acquire gigabytes of user data. The term “Not Only SQL” or “Not SQL” refers to a database that is not SQL. NoSQL has become popular, even though a better word would be “NoREL.” In 1998, Carl Strozz coined the term “NoSQL.”

Is JSON a NoSQL database?

Many people nowadays prefer JSON to XML, and a lot of NoSQL data storage utilizes it. On the other hand, JSON lacks indexing, which is why the JSONB data format was established. Instead of a basic JSON blob, JSONB holds data in binary format.

What exactly is the goal of NoSQL?

Non-structured data can be stored in NoSQL databases. The NoSQL data format is a novel way to store big datasets. When it comes to storing textual data, NoSQL is a viable alternative to SQL databases.

NoSQL Interview Questions- With Simple Answers

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