Cassandra vs PostgreSQL comparison

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Cassandra

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Executive SummaryUpdated on Mar 5, 2025

PostgreSQL and Cassandra are prominent players in the database management system category, each offering unique advantages. PostgreSQL stands out for its adherence to SQL standards and robust feature set, while Cassandra excels in scalability and handling high data volumes. Based on the comparison, PostgreSQL's rich functionality and cost-effectiveness give it an edge for feature-rich applications, whereas Cassandra's superior scalability is ideal for large-scale data needs.

Features: PostgreSQL boasts SQL standards compliance, extensive complex query support, and ACID compliance, making it ideal for transactional applications. It supports asynchronous commit and offers strong scalability for write-intensive tasks. Cassandra focuses on handling vast data volumes with high availability, thanks to its peer-to-peer architecture. Its real-time analysis capability and linear scalability are valuable for write-heavy workloads.

Room for Improvement: PostgreSQL could enhance its read-only query handling, offer better support for SQL commands like 'INSERT IGNORE,' and address the absence of unsigned integer data types. It also lacks sophisticated built-in clustering features. Cassandra's management complexity is a challenge, with room to improve query optimization and integration capabilities, simplifying setup and maintenance.

Ease of Deployment and Customer Service: Both PostgreSQL and Cassandra are flexible across on-premises, hybrid, and cloud environments. PostgreSQL benefits from a strong community with ample documentation, though official customer service is not as direct as paid services. Cassandra is community-driven but lacks a centralized knowledge base, relying on open-source support.

Pricing and ROI: Both PostgreSQL and Cassandra provide open-source solutions with minimal direct costs. PostgreSQL offers lower hardware and operating expenses due to GPL licensing, while Cassandra's open-source nature is cost-effective; however, DataStax Enterprise may incur additional support costs. Both achieve significant ROI from the lack of licensing fees and adaptable scalability.

To learn more, read our detailed Cassandra vs. PostgreSQL Report (Updated: April 2026).

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Cassandra vs. PostgreSQL

April 2026

Helped 893,221 peers since 2012

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 Vector Databases

14th

Average Rating

8.0

Reviews Sentiment

6.0

Number of Reviews

Ranking in other categories

NoSQL Databases (7th)

PostgreSQL

Ranking in Vector Databases

6th

Average Rating

8.4

Reviews Sentiment

7.4

Number of Reviews

127

Ranking in other categories

Open Source Databases (1st)

Mindshare comparison

As of May 2026, in the Vector Databases category, the mindshare of Cassandra is 3.4%, up from 1.7% compared to the previous year. The mindshare of PostgreSQL is 7.9%, up from 4.9% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Vector Databases Mindshare Distribution
Product	Mindshare (%)
PostgreSQL	7.9%
Cassandra	3.4%
Other	88.7%

Vector Databases

Featured Reviews

Monirul Islam Khan

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.

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Shobhit Goel

Data Science Architect at publicis Sapient

High-volume transactions have reduced failures and improve customer service efficiency

The best feature is performance, because of which I decided on PostgreSQL. I have also enabled the PG vector plugin on top of PostgreSQL. I have the opportunity to use two different features and two different flavors in a single product, which is the best thing about PostgreSQL. Initially, we had some hiccups around the performance part, but later we did indexing in PostgreSQL and now it is working very well. Even when we are doing 100,000 transactions in a day, PostgreSQL is working excellently. The interface is another best feature. If I need to do any query, I simply install the plugin on my local, which is pgAdmin. Through pgAdmin, I am able to communicate with PostgreSQL and execute all my SQL queries. I am getting a better UI with PostgreSQL as the backend, which is also one of the best options. PG vector is also very strong from PostgreSQL where I have implemented RAG and on a daily basis, I inject thousands of pages of PDF. More than 100 PDFs are coming into my system and one PDF is around 1,000 pages. We are injecting them into PostgreSQL and converting them into dimensions and inserting them into PG vector. The level of transactions we are doing on a daily basis is substantial, and we are getting very good throughput and low latency from PostgreSQL. When we were doing more than 50,000 transactions in a minute with the previous database, we were getting a lot of latency issues with threads getting blocked and abruptly closed unwantedly. After doing extensive research, we decided to move to PostgreSQL. Now, we are doing around 100,000 transactions in PostgreSQL and we are getting good throughput with no latency.

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Quotes from Members

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

Pros

"Overall, I would rate Cassandra as nine because of its fast writes, which really suit our use cases mostly."

"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 time series data was one of the best features along with auto publishing."

"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."

"It's used as our cloud based backend store as a temporary cache and for storing data that streams through our data pipe."

"The solution's database capabilities are very good."

"The most valuable features of Cassandra are its scaling capabilities and its non-SQL nature capabilities."

"Its retrieval is similar to an RDBMS, so our team finds it easy to adapt."

More Cassandra pros

"It is very simple to manage."

"The solution provides complete support in terms of the SQL dialect and behaves nicely when it comes to transactions."

"We use the solution to store tables. It is stable and performs well."

"The spatial extension, PostGIS, is amazing and probably the gold standard."

"We switch to this solution due to its stability and that it is open source."

"The PostgreSQL database is similar to the SQL Server but has a slightly different technology that has similar resources as well, and if the customer has the confidence using SQL Server, they will be fairly comfortable using this solution."

"The community support and the open-source community for it are good."

"PostgreSQL is an open source database engine that is very powerful, highly configurable, and more flexible than MySQL or MariaDB because you can create several databases with many schemas and define roles like owners, not only grants over tables or procedures."

Cons

"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."

"The secondary index in Cassandra was a bit problematic and could be improved."

"Some issues arise from our vendors like Apache slowness and distribution or load balancing from HAProxy, which should better handle consumption for high-level concurrency."

"It can be difficult to analyze what's going on inside of the database relative to other databases."

"The initial setup of Cassandra can be difficult in the configuration. There might be a need to have assistance. The implementation process can six months for connecting to certain databases."

"The solution is not easy to use because it is a big database and you have to learn the interface. This is the case though in most of these solutions."

"The secondary index in Cassandra was a bit problematic and could be improved."

More Cassandra cons

"The interface climate could be better."

"The only thing that could potentially be improved is PGAdmin3, the DB Client that's has not been updated in quite a while."

"PostgreSQL could be used for small to medium databases but not for a huge production database."

"Defaults for PostgreSQL are very low."

"The search option is not very good."

"That said, there is a learning curve when it comes to server configuration."

"I find, sometimes, that it is too restrictive in cross-table/view constraints."

"The product has room for improvement with horizontal scalability and multi-master replication options, where community work is already in progress."

Pricing and Cost Advice

"We pay for a license."

"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."

"There are licensing fees that must be paid, but I'm not sure if they are paid monthly or yearly."

"I don't have the specific numbers on pricing, but it was fairly priced."

"We are using the open-source version of Cassandra, the solution is free."

"Affordable solution."

"The licensing model is good."

"This solution can offer a cheaper choice for customers since it is open-source."

"The solution requires a license."

"We do not pay for licensing."

"It is free. There is no license on it."

"It is open source. There is no licensing."

"It is free. In terms of operating costs, it basically needs the same platform on which Oracle runs."

Top Industries

By visitors reading reviews

Financial Services Firm

16%

Comms Service Provider

Computer Software Company

Retailer

Financial Services Firm

11%

Computer Software Company

11%

Comms Service Provider

10%

Manufacturing Company

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	9
Midsize Enterprise	2
Large Enterprise	14

By reviewers
Company Size	Count
Small Business	57
Midsize Enterprise	27
Large Enterprise	47

Questions from the Community

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 is your primary use case for Cassandra?

My use case for Cassandra is for a document and other unstructured data management system as well as structured data for ultra-poor member community edition, community members' PII information, so ...

How does Firebird SQL compare with PostgreSQL?

PostgreSQL was designed in a way that provides you with not only a high degree of flexibility but also offers you a cheap and easy-to-use solution. It gives you the ability to redesign and audit yo...

What do you like most about PostgreSQL?

It's a transactional database, so we use Postgres for most of our reporting. That's where it's helping.

What is your experience regarding pricing and costs for PostgreSQL?

I purchased from the marketplace, so licensing and pricing cost is acceptable. To be honest, there is a separate team who handles the cost of licensing everything. I have admin access on Azure and ...

MongoDB Enterprise Advanced vs Cassandra

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Compared 5% of the time

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Compared 16% of the time

MySQL vs PostgreSQL

Compared 8% of the time

MariaDB vs PostgreSQL

Compared 6% of the time

LanceDB vs PostgreSQL

Compared 5% of the time

Chroma vs PostgreSQL

Compared 5% of the time

Product Reports

Download Cassandra product report

Cassandra

May 2026

Download PostgreSQL product report

April 2026

Overview

Cassandra is a distributed and scalable database management system used for real-time data processing.

It is highly valued for its ability to handle large amounts of data, scalability, high availability, fault tolerance, and flexible data model.

It is commonly used in finance, e-commerce, and social media industries.

Apache

PostgreSQL is a versatile and reliable database management system commonly used for web development, data analysis, and building scalable databases.

It offers advanced features like indexing, replication, and transaction management. Users appreciate its flexibility, performance, and ability to handle large amounts of data efficiently. Its robustness, scalability, and support for complex queries make it highly valuable.

Additionally, PostgreSQL's extensibility, flexibility, community support, and frequent updates contribute to its ongoing improvement and stability.

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

1. Apple 2. Cisco 3. Fujitsu 4. Instagram 5. Netflix 6. Red Hat 7. Sony 8. Uber 9. Cisco Systems 10. Skype 11. LinkedIn 12. Etsy 13. Yelp 14. Reddit 15. Dropbox 16. Slack 17. Twitch 18. WhatsApp 19. Snapchat 20. Shazam 21. SoundCloud 22. The New York Times 23. Cisco WebEx 24. Atlassian 25. Cisco Meraki 26. Heroku 27. GitLab 28. Zalando 29. OpenTable 30. Trello 31. Square Enix 32. Bloomberg