> Are you sure?

No, and anyone who says yes is lying. (Lockless NFS exists and is no fun.)

> Well, fundamentally it’s very hard to get it exactly right, and I imagine that’s why the implementation is a little involved

SQLite has set itself the horrible task of updating files in-place. I know of two reliable, simpler alternatives:

1. Appending to files through O_APPEND

2. Rewriting files through rename()

If SQLite has different magic syscalls then I would very much like to learn.