Database Design: Relation Predicates and “Identical Relations”
I found this approach deeply troubling because it moves us away form semantic design towards logic design... which always runs into problems when the database itself becomes semantic content.  The write up was rather confusing.<p>The solution seems straightforward.  A single table that captures the meaning expressed by the separate VIEWS and DOWNLOADS tables.  eg. USERACTION (USER_ID, ITEM_ID, ACTIONTYPE)   where ACTIONTYPE is a value like V for view and D for download.  Of course, that solution is hard to see because it&#x27;s a synthesis of meanings occurring at different levels and not the product of predicate logic.