Data dictionary views for managing users

DBA_USERS

DBA_ROLES

DBA_COL_PRIVS

DBA_ROLE_PRIVS

DBA_SYS_PRIVS

DBA_TAB_PRIVS

ROLE_ROLE_PRIVS

ROLE_SYS_PRIVS

ROLE_TAB_PRIVS

SESSION_PRIVS

SESSION_ROLES