Hi ML, I wonder if someone has already experiment some kind of unique index on a column family key.
Let's go for a short example : the key is the username. What happens if 2 users want to signup at the same time with the same username ? So has someone already addressed this "pattern" in Cassandra point of view ? My idea to solve such use case is to have both thread writing the username, but with a colum like "lock-<RANDOM VALUE>", and then read the row, and find out if the first lock column appearing belong to the thread. If this is the case, it can continue the process, otherwise it has been preempted by another thread. Has someone another idea to share ? Thanks in advance, Kind regards, Benoit.
