IMO you’re overcomplicating it.
- Ghost uses Knex (and bookshelf, but let’s ignore that for this conversation) instead of writing raw SQL. Knex is relatively agnostic when it comes to SQL backends, allows for parameterized queries, and handles connection pooling. It also does a lot of other stuff.
- In the past, Ghost has supported multiple databases (including PostgreSQL at one point), but the core team doesn’t have the bandwidth/knowledge to maintain support.
- Ghost (Pro) uses MySQL in production. Around the time of Ghost 5.0.0, MySQL 5 was EoL’d, and MySQL 8 is the next version.
- Ghost announced that MySQL 8 will be required for Ghost 5.0.0 to streamline the database support requirements, and reiterated (probably a bit more forcefully) that MariaDB was never officially supported
- MySQL 8 diverged more from MariaDB than MySQL 5
- Some MariaDB users have had issues with Ghost migrations over the past few years after the Ghost 5.0.0 announcement. There’s not just 1 bug in Knex. You can search the Ghost issues page to see the migration issues.
What has simply been said is Ghost’s production stack is designed for MySQL 8. What I’m saying is feel free to try another database, but don’t be surprised if stuff randomly breaks.