It is a mainly in-memory SQL database library with write to disk. You use it as you would MySQL or any other SQL database. Typically, SQL databases are much better at fast writes than nosql type databases. InfluxDB should be an exception to that rule according to the vendors but then SQLite is so small and well written, I think it would be really hard to beat for fast sequential writes.
There is a SQLlite node. You would need to know some SQL but it isn't too hard to learn and is fairly similar to the QL used in InfluxDB.
@ghayne thanks for the reference to the ESP libary for InfluxDB, I wasn't aware of that. Though, in hindsight, it should be fairly simple since IDB uses REST for all queries and updates.