The use of keys is instrumental in database management. Primary keys allow for distinct records and foreign keys tie records together to create unique relationships between two or more entities and/or tables. In Blockchain, we know that a hash is the equivalent to a key – and makes the chain secure and indisputable (or so we think). Why is it then that with an RDBMS, a primary key and foreign key can still create redundancy, thereby causing data anomalies? Can the same be said about blockchain?