> 2. Is it possible to build a hybrid database schema? For example, SQLite+JSON? Postgres and MySQL both have JSON support that can do fancy things which inclu

> 2. Is it possible to build a hybrid database schema? For example, SQLite+JSON? Postgres and MySQL both have JSON support that can do fancy things which includes indexes, but it's extra work and I don't think it actually gains you anything. I'd recommend using regular old columns for anything you ever plan to want a query on. But if you have other stuff, it's perfectly reasonable to dump a bunch of random garbage into a JSON column. People use this for things like user settings, and are generally happy with it. > 4. Is it possible to build a custom file format based on SQLite or hybrid one based on SQLite+JSON? SQLite is already basically a file format. You can store JSON blobs in strings somewhere inside it if that's convenient.