Comment by andix

It's something completely different. A database like SQLite runs in the same process as the application

All the filesystem calls go through the kernel. A userspace file system is another process.

It's not like SQLite, it's more like Postgres. Try sending a few hundred thousand small queries to Postgres, and be surprised how slow it's going to be.

The file system api is not like sql that allows complex queries. It's a lot of tiny and simple requests that assume very low latency.