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Cassandra vs Microsoft Azure Cosmos DB comparison

 

Comparison Buyer's Guide

Executive SummaryUpdated on Jan 25, 2026

Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Categories and Ranking

Cassandra
Ranking in NoSQL Databases
7th
Ranking in Vector Databases
14th
Average Rating
8.0
Reviews Sentiment
6.0
Number of Reviews
25
Ranking in other categories
No ranking in other categories
Microsoft Azure Cosmos DB
Ranking in NoSQL Databases
2nd
Ranking in Vector Databases
1st
Average Rating
8.2
Reviews Sentiment
6.9
Number of Reviews
109
Ranking in other categories
Database as a Service (DBaaS) (4th), Managed NoSQL Databases (1st)
 

Mindshare comparison

As of January 2026, in the NoSQL Databases category, the mindshare of Cassandra is 8.0%, down from 12.3% compared to the previous year. The mindshare of Microsoft Azure Cosmos DB is 6.7%, up from 1.4% compared to the previous year. It is calculated based on PeerSpot user engagement data.
NoSQL Databases Market Share Distribution
ProductMarket Share (%)
Microsoft Azure Cosmos DB6.7%
Cassandra8.0%
Other85.3%
NoSQL Databases
 

Featured Reviews

Monirul Islam Khan - PeerSpot reviewer
Head, Data Integration & Management at a non-profit with 10,001+ employees
Has maintained secure document storage and efficient data distribution with peer-to-peer architecture
The functions or features in Cassandra that I have found most valuable are that it is a distributed system similar to Mongo. It's good enough for comparison with another SQL database, so it's smooth and organized for distributed database system. The peer-to-peer architecture in Cassandra is helpful for network decentralization, and I have already introduced that feature. Cassandra features in peer-to-peer as well as another monitoring, so basically, it's good enough for our service. The tunable consistency level in Cassandra is good, and we are using that feature already. In terms of built-in caching and lightweight transactions in Cassandra, the transaction level is good, and it's optimized, so there are no more issues in that database. Based on my experience, Cassandra is good for document management system, as well as distributed database system, and the automatic recovery process is there. Additionally, the database monitoring system or auditing system is well-comparable with other database systems, so we are actually happy to be using this Cassandra database.
reviewer2724105 - PeerSpot reviewer
Senior Director of Product Management at a tech vendor with 1,001-5,000 employees
Provides super sharp latency, excellent availability, and the ability to effectively manage costs across different tenants
For integrating Microsoft Azure Cosmos DB with other Azure products or other products, there are a couple of challenges with the current system. Right now, the vectors are stored as floating-point numbers within the NoSQL document, which makes them inefficiently large. This leads to increased storage space requirements, and searching through a vast number of documents in the vector database becomes quite costly in terms of RUs. While the integration works well, the expense associated with it is relatively high. I would really like to see a reduction in costs for their vector search, as it is currently on the expensive side. The areas for improvement in Microsoft Azure Cosmos DB are vector pricing and vector indexing patterns, which are unintuitive and not well described. I would also like to see the parameters of Fleet Spaces made more powerful, as currently, it's somewhat lightweight. I believe they've made those changes intentionally to better understand the cost model. However, we would like to take a more aggressive approach in using it. One of the most frustrating aspects of Microsoft Azure Cosmos DB right now is that you can only store one vector per document. Additionally, you must specify the configuration of that vector when you create an instance of Microsoft Azure Cosmos DB. Once the database is set up, you can't change the vector configuration, which is incredibly limiting for experimentation. You want the ability to try different settings and see how they perform, as there are numerous use cases for storing more than one vector in a document. While interoperability within the vector database is acceptable—for example, I can search for vectors—I still desire a richer set of configuration options.

Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Pros

"The technical evaluation is very good."
"Since I haven't had years of experience with it, it's still new to me. One valuable feature is its distribution, so I can run it partly in the cloud and part on-prem. That's a feature I'd like to use but haven't yet because we're trying to move to Azure. I don't know if or when that will happen. Ideally, we'd have it distributed over the cloud and on-prem simultaneously, so if something happens to our on-prem, we can keep going in the cloud, like a pay-as-you-go model with Azure."
"Cassandra is good. It's better than CouchDB, and we are using it in parallel with CouchDB. Cassandra looks better and is more user-friendly."
"The most valuable features are the counter features and the NoSQL schema. It also has good scalability. You can scale Cassandra to any finite level."
"Cassandra offers high availability and fault tolerance, making it suitable for large-scale data storage and real-time processing."
"The solution's database capabilities are very good."
"The most valuable feature of Cassandra is its fast retrieval. Additionally, the solution can handle large amounts of data. It is the quickest application we use."
"Some of the valued features of this solution are it has good performance and failover."
"What I appreciate most are the latency and the access, which are guaranteed by the tool, which is really impressive."
"The scalability and ease of use with the APIs of Microsoft Azure Cosmos DB have allowed us to meet our customers' expectations pretty easily with little barrier to entry."
"The most valuable feature of Microsoft Azure Cosmos DB is its ability to handle concurrency and consistency."
"Our team has found the vCore index to be one of the most valuable features. We have tokenized and vectorized our entire database and stored this data in MongoDB collections with a vCore index, which works like magic for keyword selection."
"Cosmos DB is a pretty stable solution. I would rate it a ten out of ten."
"Overall, I would rate Microsoft Azure Cosmos DB a nine out of ten."
"Microsoft Azure Cosmos DB has reduced our total cost of ownership by about half, allowing us to sell our product for about half of what we were selling it before, and Microsoft Azure Cosmos DB is probably 70% of the reason why that's true."
"Latency and availability are incredible."
 

Cons

"The solution is limited to a linear performance."
"Cassandra is very complex to manage. Sometimes, I need to involve a senior DevOps engineer if we encounter a problem."
"It can be difficult to analyze what's going on inside of the database relative to other databases. It can also be difficult to troubleshoot sometimes."
"Cassandra can improve by adding more built-in tools. For example, if you want to do some maintenance activities in the cluster, we have to depend on third-party tools. Having these tools build-in would be e benefit."
"Batching bulk data can cause performance issues."
"The secondary index in Cassandra was a bit problematic and could be improved."
"Cassandra could be more user-friendly like MongoDB."
"Interface is not user friendly."
"I have to say technical support is not very good as it takes too long. Sometimes it can take them two or three days to respond to your ticket."
"The main area of improvement is the cost, as the expense is high. Also, when writing processes into Cosmos, sometimes the threshold is met, which can be a problem if developers have not written the code properly, limiting calls to five thousand. These aspects need addressing."
"What is missing in Microsoft Azure Cosmos DB is definitely cold storage. We know it's coming, but that's currently what is missing—the possibility to park older data in a cold tier."
"We would like to see advancements in AI with the ability to benchmark vector search capabilities, ensuring it answers questions accurately. During our initial implementation, we faced challenges with indexing and sorting, which are natively available in other offerings but required specific configurations in Cosmos."
"Because there is no local way of doing things, Azure Cosmos DB will always be considered expensive."
"It would be nice to have more options to ingest the data, for example, more file options or more search options. Currently, you can use JSON, but if there were other file types you can use for data ingestion, that would be nice."
"We should have more freedom to tweak it and make our own queries for non-traditional use-cases."
"One of the primary challenges with Cosmos DB as a non-relational data store is the careful data modeling required due to the lack of collection-level joins when using the SQL API."
 

Pricing and Cost Advice

"I don't have the specific numbers on pricing, but it was fairly priced."
"I use the tool's open-source version."
"Cassandra is a free open source solution, but there is a commercial version available called DataStax Enterprise."
"We are using the open-source version of Cassandra, the solution is free."
"There are licensing fees that must be paid, but I'm not sure if they are paid monthly or yearly."
"We pay for a license."
"The cost is the biggest limitation of this solution."
"The customer had a high budget, but it turned out to be a little bit cheaper than what they expected. I am not sure how much they have spent so far, but they are satisfied with the pricing."
"The price of Microsoft Azure Cosmos DB could be a bit lower."
"Pricing is mid- to high-end."
"Pricing is one of the solution's main features because it is based on usage, scales automatically, and is not too costly."
"We are not consuming so much yet since we are at the beginning of using this solution. I would rate the pricing of Microsoft Azure Cosmos DB a six out of ten."
"Microsoft Azure Cosmos DB pricing is based on RUs. Reading 1 KB document costs one RU, whereas writing one document costs five RUs. Pricing for querying depends on the complexity of the query. If you increase the document size, it will automatically increase the RU cost."
"Azure Cosmos DB's pricing is competitive, though there is a need for more personalized pricing models to accommodate small applications without incurring high charges. A suggestion is to implement dynamically adjustable pricing that accounts for various user needs."
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Top Industries

By visitors reading reviews
Financial Services Firm
16%
Computer Software Company
7%
Comms Service Provider
7%
Retailer
7%
Legal Firm
13%
Financial Services Firm
11%
Comms Service Provider
9%
Manufacturing Company
8%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
By reviewers
Company SizeCount
Small Business8
Midsize Enterprise1
Large Enterprise14
By reviewers
Company SizeCount
Small Business33
Midsize Enterprise21
Large Enterprise58
 

Questions from the Community

What do you like most about Cassandra?
The use of Cassandra in real-time data analytics has been pivotal for our e-commerce platform. As our platform operates 24/7, providing services to sellers and customers alike, the need for real-ti...
What is your experience regarding pricing and costs for Cassandra?
The pricing for Cassandra is a little bit high, so it would be better for our community services if they consider community pricing for any non-profit organization like an NGO or other things. It w...
What needs improvement with Cassandra?
Regarding areas of improvement for Cassandra, currently, we are not facing significant issues. Some issues arise from our vendors like Apache slowness and distribution or load balancing from HAProx...
What do you like most about Microsoft Azure Cosmos DB?
The initial setup is simple and straightforward. You can set up a Cosmos DB in a day, even configuring things like availability zones around the world.
What is your experience regarding pricing and costs for Microsoft Azure Cosmos DB?
Microsoft Azure Cosmos DB's pricing model has aligned with my budget expectations because I can tune the RU as I need to, which helps a lot. Microsoft Azure Cosmos DB's dynamic auto-scale or server...
What needs improvement with Microsoft Azure Cosmos DB?
I have not utilized Microsoft Azure Cosmos DB multi-model support for handling diverse data types. I'm not in the position to decide if clients will use Microsoft Azure Cosmos DB or any other datab...
 

Also Known As

No data available
Microsoft Azure DocumentDB, MS Azure Cosmos DB
 

Overview

 

Sample Customers

1. Apple 2. Netflix 3. Facebook 4. Instagram 5. Twitter 6. eBay 7. Spotify 8. Uber 9. Airbnb 10. Adobe 11. Cisco 12. IBM 13. Microsoft 14. Yahoo 15. Reddit 16. Pinterest 17. Salesforce 18. LinkedIn 19. Hulu 20. Airbnb 21. Walmart 22. Target 23. Sony 24. Intel 25. Cisco 26. HP 27. Oracle 28. SAP 29. GE 30. Siemens 31. Volkswagen 32. Toyota
TomTom, KPMG Australia, Bosch, ASOS, Mercedes Benz, NBA, Zero Friction, Nederlandse Spoorwegen, Kinectify
Find out what your peers are saying about Cassandra vs. Microsoft Azure Cosmos DB and other solutions. Updated: January 2026.
881,082 professionals have used our research since 2012.