Apache Cassandra vs PostgreSQL

Apache Cassandra is a free, open-source NoSQL distributed database for mission-critical data and large active datasets. Its masterless architecture gives each node the same functionality. The project says read and write throughput can grow linearly as machines are added, without downtime or application interruption. Cassandra can run on premises, with one cloud provider, across multiple providers, or in a combination of those environments. It supports replication across data centers and configurable consistency levels for queries, along with CQL, transactions, and horizontal scaling. The project lists audit logging for DML, DDL, and DCL activity, and fqltool for recording and replaying production workloads. Drivers are available for Java, Go, Python, and Node.js; downloads include tarballs and packages, and installation guidance covers Debian and RPM. The ecosystem includes tools and connectors for Apache Kafka, Apache Flink, Apache Spark, and Kubernetes. The project identifies version 5.0 as the latest GA release and says it is maintained until the 8.0 release. Cassandra is self-managed, and listed third-party ecosystem projects are not supported by its community.

PostgreSQL is a free, open-source database system for storing and scaling complex data workloads. It uses SQL and adds object-relational capabilities, with support for primitive and structured values as well as documents, geometric data, and custom types. Its supported formats include JSON/JSONB, XML, arrays, ranges, and UUIDs. For data integrity, it provides keys, constraints, locks, transactions, savepoints, and SQL-standard transaction isolation levels. Performance tools include multiple index types, query planning and optimization, parallel processing, partitioning, just-in-time expression compilation, and asynchronous I/O. Recovery and availability features include write-ahead logging, several replication methods, point-in-time recovery, and active standbys. Security options include multiple authentication methods, access controls, row- and column-level security, and multi-factor authentication. Extensions, procedural languages, and foreign data wrappers can connect PostgreSQL to other databases or streams. It runs on Linux, macOS, and Windows, and is self-hosted; no managed service is listed. The PostgreSQL License permits use, copying, modification, and distribution without a fee, subject to its conditions.