Methods, systems, and computer-readable storage media for quantifying a redundancy of data stored in tables of a database. In some implementations, actions include, for each primary key and table pair in a set of primary key and table pairs, determining an aggregate severity sub-score based on one or more values of the primary key in the table, the primary key being included in a set of primary keys and the table being included in a set of tables, determining an aggregate severity score for each primary key in the set of primary keys based on aggregate severity sub-scores associated with the primary key to provide a plurality of aggregate severity scores, each aggregate severity score indicating a relative redundancy of values of the primary key across all tables in the set of tables, and providing a list of aggregate severity scores and corresponding primary keys for display to a user.