Ask HN: Which database would you choose for a blockchain?

OK, OK, I said the cursed "B" word. Feel free to mock me for being in the crypto space.

That said, I am in the process of building a blockchain (funded and all, not a hobby project) and I am exploring the various database options.

The only requirements (just lol) are: - Must be completely local - Must be very performant especially in concurrent reads and writes

I am using sqlite3 as a dummy but of course it is not suitable and not scalable enough.

I was wondering if PostgreSQL might be an idea but I am very basic in my knowledge of databases.

In your opinion, given the high throughput and concurrency, where should I start looking?

Bonus points if it is open source of course