There are few people who have used both MySQL and Postgresql in production at scale. Both are great Open Source databases, so I thought I’d add some comments on both based on my experience.
| Feature | MySQL/InnoDB | Postgresql |
|---|---|---|
| Replication | Many options | Few built-in options |
| Index Write Amplification | No | Yes |
| Error handling on disk full | Sketchy | Yes |
| Grants complexity | Simple to understand | Complex |
| Sync and Semi-sync options | Several | Yes |
| Easy-to-use CREATE PARTITION | Yes | PG 10+ |
| CHECK CONSTRAINT | Ignored | Yes |
| CTE (WITH) | MySQL 8+ | Yes |
| ON DUPLICATE KEY | Yes | PG 9.5+, but odd |
| Partial Indexes | No | Yes |
| Functional Indexes | No | Yes |
| DELETE Purging | Automatic Purge thread | VACUUM |
| Object Names | Finely-scoped | Globally-scoped |
| Invisible Indexes | 8.0+ | hypopg extension |