Cache will only do a write lock on /a, /a/b, and /a/b/c for the node creation. After that, only write lock on /a/b/c.
Thanks for your reply. So. for updating node c, the entire path /a/b/c will have a write lock, correct? So, I cannot update 2 nodes /a/b/c and /a/b/d simultaneously as /a/b will have a write lock. Thanks again.
No, a and a/b will have a RL, a/b/c a WL. So you can update /a/b/c and a/b/d concurrently, except with isolation level SERIALIZABLE (where RLs cannot be concurrently held)