PostgreSQL (alternately Postgres) is a free and open source object-relational database system boasting over 30 years of active development, reliability, feature robustness, and performance. It supports SQL and is designed to support various workloads flexibly.
Four years ago, I needed to choose a web-scale database. Having used relational databases for years (PostgreSQL is my favorite), I needed something that could perform well at scale with no downtime. I considered VoltDB for its in-memory speed, but it's limited in scale. I …
DynamoDB is good and is also a truly global database as a service on AWS. However, if your organization is not using AWS, then Cassandra will provide a highly scalable and tuneable, consistent database. Cassandra is also fault-tolerant and good for replication across multiple …
Cassandra is the only NoSQL database I have extensive experience with. In terms of other open source database solutions, I can say that I like Cassandra as much or equally as traditional Oracle MySQL, and a lot more than PostgresSQL. The decision to use Cassandra was driven by …
PostgrPostgreSQL as a transaction db engine against oracle and sql server works well. TPM wise compared to MySQL and MariaDB, on an evan scale. SQL function supports, far outweighs compared to MySQL and MariaDB. PG Extensions allow for flexibiltity and scalability. Allows …
As I have been telling all along, PostgreSQL is much cheaper compared to the other RDBMS solutions. It has got better performance with some of the application services that we are using and is easy to maintain. Overall, we are satisfied migrating to PostgreSQL database clusters.
It's a viable alternative, with a rich feature set and a reliable system. PostgreSQL is one of the best RDBMS's currently on the market in 2020, it serves just as well as a starter, PoC DB for any software idea as a final, highly valuable database solution for big systems.
Apache Cassandra and PostgreSQL (or Postgres) are popular open-source databases; Apache Cassandra is NoSQL and boasts high availability. PostgreSQL is an object-relational database and overall one of the world’s most adopted database management systems after only MySQL, Oracle, and Microsoft SQL Server. Cassandra is available free under the Apache License 2.0 and PostgreSQL is free under the liberal PostgreSQL License, which is similar to the BSD or MIT licenses.
PostgreSQL and Cassandra are frequently compared but not necessarily competitors as each is suitable for different use cases. PostgreSQL is deployed at companies of all sizes and enterprises, while Cassandra is more often deployed at larger companies and enterprises given its focus on helping users manage large volumes of possibly unstructured data across multiple data centres.
Features
There are differing reasons to deploy either Apache Cassandra or PostgreSQL for a project.
Cassandra is a wide column store suitable for supporting high velocity read and write. It is liked for its core competency, which in its case is scalability and availability. Other advantages users point out is that it is low maintenance, able to perform well on low cost commodity hardware, and that CQL (Cassandra Query Language) is easy to use, being somewhat similar to SQL.
PostgreSQL, unlike Cassandra, is an object-relational database that is typically associated to BI & analytics use cases, and supports sometimes needed complex design with seldom used but powerful features like function overloading and table inheritance. PostgreSQL is popular for a reason: users get, for free and with great open source community support, a highly programmable, feature-rich, fast, JSON & geospatial mapping capable, easy to implement, and all-around good at everything database.
Limitations
For specific use cases, there are reasons to go in a different direction than building with a Cassandra or PostgreSQL database. Drawbacks are somewhat similar, though through the looking glass of comparing a SQL database vs. a NoSQL database.
As a key-value store users note that Cassandra can be inefficient and not as performant as alternatives, and also state that queries that are ad-hoc and don’t closely mirror the database’s particular design process will tend to not work well, or may be impossible. For this reason, users stress that competent data modeling and a basic understanding of NoSQL is a must when working with Cassandra: get an expert to set it up, or risk learning to become an expert by getting it all wrong.
PostgreSQL’s features are powerful, and for inexperienced developers can lead to disastrous, anti-performant design, and it is generally less performant than MySQL, which is why that database is preferred for use cases like powering websites or running simple queries. Also, it lacks in-memory caching. Finally, many users say it can be hard to get started, with a steep learning curve and somewhat lacking documentation.
Pricing
Apache Cassandra and PostgreSQL are open source and both are available at no cost to the user when self-hosted. Cloud hosting may be desirable, in which case pricing will depend on compute costs set by the third-party cloud providers (e.g. the Amazon Keyspaces Cassandra DBaaS, etc.) or managed hosting providers: for example Instaclustr and Aiven, among others, offer managed Cassandra; and, managed PostgreSQL is provided by, to name a few, DigitalOcean, ScaleGrid Aiven.
Features
Apache Cassandra
PostgreSQL
NoSQL Databases
Comparison of NoSQL Databases features of Product A and Product B
Apache Cassandra is a NoSQL database and well suited where you need highly available, linearly scalable, tunable consistency and high performance across varying workloads. It has worked well for our use cases, and I shared my experiences to use it effectively at the last Cassandra summit! http://bit.ly/1Ok56TK It is a NoSQL database, finally you can tune it to be strongly consistent and successfully use it as such. However those are not usual patterns, as you negotiate on latency. It works well if you require that. If your use case needs strongly consistent environments with semantics of a relational database or if the use case needs a data warehouse, or if you need NoSQL with ACID transactions, Apache Cassandra may not be the optimum choice.
PostgreSQL, unlike other databases, is user-friendly and uses an open-source database. Ideal for relational databases, they can be accessed when speed and efficiency are required. It enables high-availability and disaster recovery replication from instance to instance. PostgreSQL can store data in a JSON format, including hashes, keys, and values. Multi-platform compatibility is also a big selling point. We could, however, use all the DBMS’s cores. While it works well in fast environments, it can be problematic in slower ones or cause multiple master replication.
Continuous availability: as a fully distributed database (no master nodes), we can update nodes with rolling restarts and accommodate minor outages without impacting our customer services.
Linear scalability: for every unit of compute that you add, you get an equivalent unit of capacity. The same application can scale from a single developer's laptop to a web-scale service with billions of rows in a table.
Amazing performance: if you design your data model correctly, bearing in mind the queries you need to answer, you can get answers in milliseconds.
Time-series data: Cassandra excels at recording, processing, and retrieving time-series data. It's a simple matter to version everything and simply record what happens, rather than going back and editing things. Then, you can compute things from the recorded history.
The stability it offers, its speed of response and its resource management is excellent even in complex database environments and with low-resource machines.
The large amount of resources it has in addition to the many own and third-party tools that are compatible that make productivity greatly increase.
The adaptability in various environments, whether distributed or not, [is a] complete set of configuration options which allows to greatly customize the work configuration according to the needs that are required.
The excellent handling of referential and transactional integrity, its internal security scheme, the ease with which we can create backups are some of the strengths that can be mentioned.
Cassandra runs on the JVM and therefor may require a lot of GC tuning for read/write intensive applications.
Requires manual periodic maintenance - for example it is recommended to run a cleanup on a regular basis.
There are a lot of knobs and buttons to configure the system. For many cases the default configuration will be sufficient, but if its not - you will need significant ramp up on the inner workings of Cassandra in order to effectively tune it.
The query syntax for JSON fields is unwieldy when you start getting into complex queries with many joins.
I wish there was a distinction (a flag) you could set for automated scripts vs working in the psql CLI, which would provide an 'Are you sure you want to do X?' type prompt if your query is likely to affect more than a certain number of rows. Especially on updates/deletes. Setting the flag in the headless(scripted) flow would disable the prompt.
Better documentation around JSON and Array aggregation, with more examples of how the data is transformed.
I would recommend Cassandra DB to those who know their use case very well, as well as know how they are going to store and retrieve data. If you need a guarantee in data storage and retrieval, and a DB that can be linearly grown by adding nodes across availability zones and regions, then this is the database you should choose.
Postgresql is the best tool out there for relational data so I have to give it a high rating when it comes to analytics, data availability and consistency, so on and so forth. SQL is also a relatively consistent language so when it comes to building new tables and loading data in from the OLTP database, there are enough tools where we can perform ETL on a scalable basis.
The data queries are relatively quick for a small to medium sized table. With complex joins, and a wide and deep table however, the performance of the query has room for improvement.
There are several companies that you can contract for technical support, like EnterpriseDB or Percona, both first level in expertise and commitment to the software.
But we do not have contracts with them, we have done all the way from googling to forums, and never have a problem that we cannot resolve or pass around. And for dozens of projects and more than 15 years now.
The online training is request based. Had there been recorded videos available online for potential users to benefit from, I could have rated it higher. The online documentation however is very helpful. The online documentation PDF is downloadable and allows users to pace their own learning. With examples and code snippets, the documentation is great starting point.
We evaluated MongoDB also, but don't like the single point failure possibility. The HBase coupled us too tightly to the Hadoop world while we prefer more technical flexibility. Also HBase is designed for "cold"/old historical data lake use cases and is not typically used for web and mobile applications due to its performance concern. Cassandra, by contrast, offers the availability and performance necessary for developing highly available applications. Furthermore, the Hadoop technology stack is typically deployed in a single location, while in the big international enterprise context, we demand the feasibility for deployment across countries and continents, hence finally we are favor of Cassandra
Postgres stacks up just [fine] along the other big players in the RDBMS world. It's very popular for a reason. It's very close to MySQL in terms of cost and features - I'd pick either solution and be just as happy. Compared to Oracle it is a MUCH cheaper solution that is just as usable.
I have no experience with this but from the blogs and news what I believe is that in businesses where there is high demand for scalability, Cassandra is a good choice to go for.
Since it works on CQL, it is quite familiar with SQL in understanding therefore it does not prevent a new employee to start in learning and having the Cassandra experience at an industrial level.
The user-role system has saved us tons of time and thus money. As I mentioned in the "Use Case" section, Postgres is not only used by engineering but also finance to measure how much to charge customers and customer support to debug customer issues. Sure, it's not easy for non-technical employees to psql in and view raw tables, but it has saved engineering hundreds of man-hours that would have had to be spent on building equivalent tools to serve finance or customer support.
It provides incredibly trustworthy storage for wherever customer data dumped in. In our 6 years of Postgres existence, we have not lost a byte of customer data due to Postgres messing up a transaction or during the multiple times the hard-drives failed (thanks to ACID compliance!).
This is less significant, but Postgres is also quite easy to manage (unless you are going above and beyond to squeeze out every last bit of performance). There's not much to configure, and the out of the box settings are quite sane. That has saved us engineers lots of time that would have gone into Postgres administration.
