Cassandra vs PostgreSQL comparison

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Cassandra

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Executive SummaryUpdated on Jun 3, 2026

PostgreSQL and Cassandra both operate in the database management category. While PostgreSQL is suitable for structured data with its comprehensive features, Cassandra has the advantage in handling large-scale data quickly and reliably.

Features: PostgreSQL provides ACID compliance, geospatial support, and robust data types like JSONB, making it a versatile platform for various applications. On the other hand, Cassandra offers high availability and fault tolerance, ideal for distributed systems, and excels in managing large volumes of time-series data with exceptional speed.

Room for Improvement: PostgreSQL could improve its user-friendliness by enhancing installation tools and performance monitoring. It also needs better support for large-scale deployments and advanced analytics. Cassandra could benefit from improved handling of complex queries, particularly those involving JOIN operations, and integrating more user-friendly interfaces could broaden its usability.

Ease of Deployment and Customer Service: PostgreSQL shows flexibility in hybrid, private cloud, and on-premises environments, supported by a robust community and third-party services. Cassandra also offers diverse deployment options, excelling in cloud environments. Both rely on community-driven assistance, but PostgreSQL's tighter integration with hosting platforms gives it a slight edge.

Pricing and ROI: PostgreSQL is a cost-effective solution due to its open-source nature, offering significant savings compared to proprietary databases. Cassandra is available in a free edition, but enterprise-level features may incur additional costs if commercial support is needed through vendors like DataStax, which can be justifiable for large-scale demands.

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

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Cassandra vs. PostgreSQL

August 2026

Helped 913,683 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

12th

Average Rating

8.0

Reviews Sentiment

6.0

Number of Reviews

Ranking in other categories

NoSQL Databases (5th)

PostgreSQL

Ranking in Vector Databases

7th

Average Rating

8.4

Reviews Sentiment

7.4

Number of Reviews

128

Ranking in other categories

Open Source Databases (1st)

Mindshare comparison

As of September 2026, in the Vector Databases category, the mindshare of Cassandra is 3.9%, up from 1.9% compared to the previous year. The mindshare of PostgreSQL is 9.1%, up from 5.3% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Vector Databases Mindshare Distribution
Product	Mindshare (%)
PostgreSQL	9.1%
Cassandra	3.9%
Other	87.0%

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

"I am satisfied with the performance."

"Setup was very straightforward."

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

"Cassandra is a stable solution."

"A consistent solution."

"Based on my experience, Cassandra is good for document management system, as well as distributed database system, and the automatic recovery process is there."

"Cassandra offers high availability and fault tolerance, making it suitable for large-scale data storage and real-time processing."

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

More Cassandra pros

"Postgres has some functions called JSONB aggregators or other aggregators, which are quite useful."

"The solution is very easy to use; you don't have to be extremely knowledgeable or technical to take advantage of it, and the product is quite flexible while being one of the cheapest options on the market."

"PostgreSQL is stable. It's available, stable, and reliable."

"It is very scalable and comes with a bonus: no licensing issues as you scale with your databases."

"The solution is scalable, it is very good."

"The main value is that it is open source, which means it is free. Our organization has the initiative to go to open source to cut down on cost. Oracle costs us $6 million a year right now, which is killing us, and Postgres costs nothing. So, there is a big push to go to Postgres."

"The most valuable features are the price, stability, it is scalable and is used by our clients in small business environments, and it is a simple product to use."

"We managed to reduce the storage space needed to 10% of the original size, without affecting data integrity, and we significantly improved the performance."

Cons

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

"One of the issues with the solution is that you cannot drop write like you're able to in MongoDB and MySQL, where you can join tables."

"Row-level locking is not available; might be very helpful in update use cases."

"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."

"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 clustering needs to be better; it is getting there."

"There were challenges with the query language and the development interface. The query language, in particular, could be improved for better optimization. These challenges were encountered while using the Java SDK."

"Depending upon our schema, we can't make ORDER BY or GROUP BY clauses in the product."

More Cassandra cons

"PostgreSQL doesn't have a feature for temporal SQL, which is useful for gathering versions of data. This feature should be included in PostgreSQL. This feature is available in MariaDB, SQL Server, Oracle Database, and DB2."

"Logical replication would be a major improvement and it's already being worked on."

"One of the features it needs is a tighter integration with business intelligence software, so that the optimisation of the requests can be handled natively in the database."

"Yes, as the database grows, one has to perform a full vacuum in order to continue to work on the database."

"They need to have a better graphical interface."

"It was a bit complex to setup, although I think this was due to ignorance on the project."

"The search option is not very good."

"This extension hasn’t been updated in several releases and would benefit from an overhaul."

Pricing and Cost Advice

"Cassandra is a free open source solution, but there is a commercial version available called DataStax Enterprise."

"We pay for a license."

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

"I use the tool's open-source version."

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

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

"The need for our customers to pay for licences is contingent on their projects and budgets."

"Affordable solution."

"There is an annual license."

"The solution requires a license."

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

"We use the open-source version of PostgreSQL and not the enterprise edition."

"Our company pays for it. There are free versions available, but for advanced features, you obviously have to pay."

"PostgreSQL is open-source, so if capable admins are available then the setup cost can be $0."

Top Industries

By visitors reading reviews

Financial Services Firm

15%

Comms Service Provider

10%

Construction Company

Outsourcing Company

Financial Services Firm

11%

Comms Service Provider

10%

Outsourcing Company

Computer Software 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	58
Midsize Enterprise	26
Large Enterprise	49

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 is your experience regarding pricing and costs for PostgreSQL?

I am not directly involved in the licensing or procurement decisions, so I cannot comment in detail on the price. From an engineering perspective, PostgreSQL is cost-efficient because it is open so...

What needs improvement with PostgreSQL?

While improving reliability, I have noticed that the limitations in PostgreSQL can be complex. For large-scale deployments, configuration, performance tuning, and related tasks can be complex and i...

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Product Reports

Download Cassandra product report

Cassandra

September 2026

Download PostgreSQL product report

September 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