الملخص

This research concerned with the designing and implementation of a distributed database system for the medical purposes. The system has been applied on dental clinic unit and statistics department at Al-Khansaa Educational Hospital at Mosul, and dental clinic unit at Woman Health Care Center at Mosul as a case study. Client/server model has been used to implement the proposed system's architecture. The computers have been connected together through a local area network (LAN). Horizontal fragmentation technique has been used to distribute the database which achieved a good level of local autonomy. Oracle software were used and utilized to implement the system. It played a dramatic role in protecting data using combination of passwords and user roles hierarchies in addition to achieving transparency and data integrity concepts in the system. The proposed system simplified saving and retrieving data of dental clinics. It also provides dental clinics units  and statistics department with necessary reports and statistics. The proposed system has the ability to automatically perform daily backup for the database in addition to the manual options for database backup and recovery.