Hi, I know this is a pretty common topic, but I haven't found any solution that really satisfy me. The problem is well known: you have a table with user information with a UUID as primary key, but you want to avoid email duplicates when new users register.
The closest solution I've found is this: https://www.mail-archive.com/user@cassandra.apache.org/msg19766.html It achieves the goal of avoiding confirmed users account with the same email, but I think that does not avoid malicious users to fill your user table with pending registrations (if you don't confirm any). I know that this is a minor thing, but anyway. I have though of a solution and it would be great if you could confirm that it is a good one. Assume you have a table with the user information with a UUID as primary key, and an "index" table email_to_UUID with email as primary key. When a user registers, the server generates a UUID and performs an INSERT ... IF NOT EXISTS into the email_to_UUID table. Immediately after, perform a SELECT from the same table and see if the read UUID is the same that the one we just generated. If it is, we are allowed to INSERT the data in the user table, knowing that no other will be doing it. Does this sound right ? Is this the right way to have sort of UNIQUE columns ? Thanks in advance
