Nice comparison by EnterpriseDB.
Below Topics are included in this comparison.
- General Comparison Commentary
- Core Database Features
- Database Capacities
- Transaction Programming and Control
- Query Capabilities
- Business Intelligence and Data Warehousing
- Network/Distributed Services
- Bulk Data Management/Protection
- Security Features
- DBA Tools
- Developer Functionality
- Scalability Solutions
- High Availability Solutions
Here, one more link which can help to understand which should we select for our product or application.