> https://www.sqlite.org/whentouse.html :
I am currently relying on SQLite as main database engine for blockchain explorers, that's usually between 1 and 2 millions http queries per day, pretty much all of them hitting more than 60 GB of SQLite databases. There is a mix of simple table queries, complex joins and extensive aggregation/statistics queries. This is kind of a sweet spot for SQLite WAL: the data is queried and updated all the time, but with only one updater task. Performance is very good, better than what I see from client/server DB under much lighter loads. And the latency is just excellent: simple queries run in a matter of microseconds. And while it may not be fashionable to say so, I really like the SQL in SQLite :) There is no query that cannot be performed efficiently and with little code. Worst that happens is you need a new index or a few temporary tables to breakup a complex query in several simpler steps. I would say SQLite is perfectly suited for "front line" web servers that serve, present and generally make accessible live data coming from other systems. Eric