Cassandra vs. MongoDB: A Detailed Comparison

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Businesses collect more data than ever, requiring them to rely on data-driven decisions. Traditional Relational Databases can't keep up; they lack scalability and can't process Unstructured Data. In the early 2000s, NoSQL databases were quickly adopted by software giants who recognized their potential. However, due to limited capabilities, they weren't deemed general-purpose databases. Each NoSQL had a specific purpose and addressed a particular workload requirement.

These databases are designed for scalability. Popular NoSQL Databases include MongoDB, Apache Cassandra, Oracle NoSQL Database, and Apache HBase. Your business and data requirements should be considered when selecting the best NoSQL database.

Cassandra and MongoDB are two early NoSQL databases. Cassandra is a distributed hybrid of a tabular and key-value store, while MongoDB is a distributed document data model.

This article will give you the knowledge to decide which relational database management system, Apache Cassandra or MongoDB, best suits your business needs.

Since Cassandra has many different distributions, in this blog, we will focus specifically on Apache Cassandra in this article.

What are NoSQL Databases, and Why Do We Need One? 

NoSQL is a non-relational database that does not follow the table model of traditional relational databases. This type of database is designed for massive scalability and can store, manage and analyze large amounts of data. 

They are often used for real-time web applications, analytics, and other big data workloads where speed and availability pull data are essential. NoSQL stands for "Not only SQL" because it does not require Structured Query Language (SQL) to access data.

NoSQL is classified into four categories: column stores, document stores, key-value stores, and graph databases. It provides a flexible and dynamic, flexible data model with, high scalability, and performance compared to traditional relational databases.

With the explosive growth of data, companies need the ability to store and deploy databases that can accommodate large workloads without losing performance or availability. NoSQL databases provide flexibility regarding schema design and can handle structured, semi-structured, and unstructured data. NoSQL databases are necessary for businesses that store large amounts of data. 

They can also be used in applications where low latency is essential, such as real-time analytics, content management systems or web applications with high user traffic. NoSQL databases, such as search engines, are also great for applications that need to access a large amount of data quickly.

What is Cassandra? 

Apache Cassandra is an open-source distributed database. It's a hybrid of a tabular and key-value store, but it uses its own data model. Cassandra is designed to handle large amounts of data across many commodity servers while providing high availability with no single point of failure. It is a highly distributed NoSQL database, meaning all its nodes are equal and can handle the same tasks.

Cassandra uses asynchronous masterless replication, meaning the same data once is replicated across multiple nodes for fault tolerance. It does not have a single point of failure, as all nodes in the cluster can handle read and write requests. Cassandra also includes tunable consistency levels, flexible data storage, and easy scalability.

Cassandra has built-in replication and complete fault tolerance on multiple commodity servers. It is highly scalable and can easily handle petabytes of data. Cassandra powers the world's most popular applications, including Facebook, Instagram, Netflix, and eBay.

What is MongoDB? 

MongoDB is an open-source, document-oriented NoSQL database. It stores data in collections of documents in the form of key-value pairs. MongoDB is a distributed database that allows for horizontal scaling and high availability with no single point of failure. It's designed to be flexible, making it ideal for rapid development and agile methodologies. MongoDB is great for applications that need to quickly access a large amount of data, such as e-commerce and search engines.

MongoDB uses JSON-like documents with dynamic schemas, making storing and query data easier than relational databases. It also supports various languages including Java, Node.js, Go, and Python. MongoDB is designed to be scalable and can easily handle petabytes of data. It also allows for easy replication across multiple nodes for fault tolerance.

Cassandra vs. MongoDB: Similarities 

Both Cassandra and MongoDB are open-source NoSQL databases that store large amounts of data. Here are the similarities between the two databases:

  • Both are distributed, allowing for scalability and high availability with no single point of failure.
  • Both support flexible data models, making them well-suited for unstructured or semi-structured data.
  • Both have built-in replication for fault tolerance.
  • Both have easy scalability, allowing for the handling of petabytes of data.
  • Both provide tunable consistency levels to ensure availability and performance.
  • Both allow for fast writes and reads in distributed environments.
  • Both support multiple languages such as Java, Node.js, Go, and Python.
  • Both are used in popular applications such as Facebook, Instagram, Netflix, and eBay.
  • Both use JSON-like documents with dynamic schemas for data storage and query processing.

Cassandra vs MongoDB: Differences 

Although Cassandra and MongoDB have many similarities, they have some differences. Here are the main differences:

  • Cassandra uses a tabular data model while MongoDB uses a document-oriented data model.
  • Cassandra has an asynchronous masterless replication while MongoDB has synchronous replication with primary/secondary nodes.
  • MongoDB supports secondary indexes while Cassandra does not.
  • MongoDB offers in-built ad hoc queries and stored procedures for querying data, while Cassandra does not have such features.
  • Cassandra has better performance for write operations compared to MongoDB.
  • MongoDB offers more flexibility when it comes to schema design and data manipulation.

Code Syntax for Cassandra vs MongoDB 

CQL (Cassandra Query Language):

SELECT * FROM table1 WHERE name = 'John';


db.table1.find({name: 'John'})

Pros and Cons of Cassandra 

Cassandra has many advantages and disadvantages lets see them.


  • High scalability
  • Easy data distribution across multiple nodes
  • Fault-tolerant and highly available
  • Tunable consistency levels for better availability and performance
  • Supports various programming languages such as Java, Node.js, Go, and Python


  • No support for secondary indexes
  • No in-built query language
  • No support for stored procedures and ad-hoc queries

Pros and Cons of MongoDB 

MongoDB also has its own set of advantages and disadvantages.



  • Not suitable for complex transactions
  • No support for multi-datacenter replication
  • Slower write performance compared to Cassandra
  • Data stored in JSON-like documents can be difficult to query.

Cassandra Use Cases  

Cassandra is best for applications that require high scalability and performance. It's suitable for large-scale applications with huge data sets, such as online gaming platforms and video-on-demand services. Cassandra also supports tunable consistency levels, which can benefit some applications where availability and performance are more important than data accuracy.

Cassandra also supports various programming languages, making it a great choice for applications that must be implemented in different programming languages.

It can be a good option for many geographically distributed data and systems that need data replication and fault tolerance.

Compare & Contrast 

When comparing Cassandra vs. MongoDB, both databases have strengths and weaknesses. Cassandra is better for applications requiring high scalability and performance, while MongoDB is more suitable for complex database transactions and secondary indexes. MongoDB offers more flexibility regarding schema design and data manipulation, while Cassandra does not have such features. Furthermore, Cassandra supports various programming languages, while MongoDB does not.

Ultimately, depending on your application's use case and data requirements, you should carefully consider which database to choose. Both databases can be used for the same tasks, but each one offers unique advantages and disadvantages that must be weighed before deciding. Cassandra and MongoDB have their own strengths and weaknesses, so it's important to consider your application use case before deciding which is the right choice. You can decide between these two powerful databases with little research and careful analysis.

Which option is best for your company?

That really depends on the project requirements and your use case. Cassandra and MongoDB offer excellent features for different types of applications, so it's important to carefully consider which database is best suited for your needs before deciding. 

Ultimately, both databases can be great options. However, it's up to you to decide which one is the best fit for your application. Consider the pros and cons of Cassandra vs. MongoDB, and do research to ensure that you're selecting the right option for your project. Taking the time to make an informed decision can help you save time and money in the long run.

Final Verdict 

When choosing between Cassandra and MongoDB, several factors must be considered. Each database has strengths and weaknesses that must be carefully weighed depending on the project requirements. MongoDB is better for applications that require complex transactions and secondary indexes, while Cassandra may be more suitable for large-scale projects with huge data sets. MongoDB offers more flexibility regarding schema design and data manipulation, while Cassandra is better for applications that need high performance and scalability.

Ultimately, it's important to carefully consider your application's use case before making a decision between the two databases. Researching can help you select the best option for your project and save time and money in the long run. With a little research and careful analysis, you can decide between these two powerful databases. No matter which database management tool you choose, Cassandra and MongoDB offer great features to help you create a successful application.

Businesses now commonly store data across multiple databases. To analyze this data, it must be integrated from all sources.

Businesses can create in-house data integration solutions, though this requires significant investment, or use existing platforms such as Sprinkledata. It enables businesses to track, analyze, and report on data in a single place by using database management system providing easy integration of multiple databases. Get started now!

Written by
Soham Dutta


Cassandra vs. MongoDB: A Detailed Comparison