This includes logical (entity relationship) and physical (table, column and key) design tools for data. Physical data modeling is becoming almost mandatory for applications using relational database management systems (RDBMSs). Strong support for physical modeling is paired with facilities to manage multiple models, to submodel or extract from larger models, and to reverse-engineer a database design from established tables. Data architects/analysts and database designers/administrators are the primary targeted users of these tools, although developers are a secondary market often targeted with a subset of the complete functionality.