The gist I linked is extremely basic, just insert and read, really, and it does use WAL by default. It'll still end up with database lock, and from there it's a

The gist I linked is extremely basic, just insert and read, really, and it does use WAL by default. It'll still end up with database lock, and from there it's all shallow waters — reverting from a crashed database lock is not trivial and can cause data loss if handled improperly. Not all writes are couple milliseconds. I regularly have transactions that take 15< seconds, and it's not because the data size that's being input is large, it's just that the SQL is recursive and complex enough to warrant recursion (storing graph data).