Role of Entity Realtionship Model. Units in Entity Relationship ... Important to know wether the specialization is a partition-it influences the implementation ...
abstraction. Data models serve for describing the structure ... Abstraction level is law-the programmer should know the physical level for writing new programs ...
unlock(X) This simple tehnique is not satisfactory, the system throughput ... The transaction does not submit an UNLOCK(A) statement, if the data item A has ...
K sz lt a HEFOP-3.3.1-P.-2004-06-0018/1.0 projekt keret ben. Database ... if this driver is assigned to drive a bus, a tram and an underground vehicle? ...