For the specific use case in question, what I've been doing for years is not just hashing the data, but hashing an internal secret AND the data. The secret isn't stored in the database anywhere (usually an env var but could be a secret in vault or other outside config), so our hashes are deterministic (and don't need a seperate salt for each one), but our hashes will never cooincide with another system's hashes. I didn't see this mentioned in article but didn't read thoroughly, I thought this was a pretty good compromise but curious for other perspectives/forget if I read this technique somewhere or just made it up as a reasonably good safeguard.