S.no PostgreSQL MySQL
1. PostgreSQL is open-source software. MySQL has several paid editions.
2. It is ACID compliant from the ground up. It is only ACID compliant when suing NDB and InnoDB Cluster Storage engines.
3. Largely SQL compliant Partially compliant to some of the SQL versions
4. Used for large systems where to write and read speeds are crucial, and data need to be validated. Used for web-based projects that require a database for data transaction
BY Best Interview Question ON 15 Apr 2020