The p-type data model was designed first to answer database needs. Some of its features were and still are quite unusual for a DBMS and, by some aspects, make it nearer Description Logic (DL) systems than classical DBMS. Views play a central role in the model. They are defined in a hierarchical manner, with constraints on role (attribute) types as in DLs, and instance classification (view recognition) is a basic mechanism in p-type implementation by the Osiris system.