@gosha If it helps, some of my hacks/tools use postgres. It's not the single source of truth then, but makes some concepts easier.
E.g. my investments now have quarterly "price" entries: so a chart of "net worth over time" will be very coarse. Adding daily prices helps, and putting it in a prices.ledger that gets included makes it somewhat manageable. But if I need hourly pricing, which I rarely need, I'll copy it into a postgres db.