قاعده البيانات هي مجموعات بيانات موحده وذات العلاقه المتبادله فيما بينها والمخزنه بدون زياده غير ضروريه او ضاره لاستخدامها في نظم عديده للمعلومات
[RIGHT]A database is a mechanized, shared, formally defined and centrally controlled of data
[RIGHT]DBMS (database management system):
[RIGHT]Collection of programs that manages database structure and controls access of data or it is a software package designed to store and manage databases
[RIGHT]Ms Access, oracle, sql, db2 etc
[RIGHT]Computer file system was used in early database design which has many problems like:
[RIGHT]*redundancy (duplication of data)
[RIGHT]*wasteful of space (storage)
[RIGHT]*update inefficiencies (when a teacher moves to anew address or changes her name, the teacher’s record must be changed each place it is stored )
[RIGHT]*data inconsistency (different addresses for the same teacher in different files)
[RIGHT] E-commerce: inventory of books, cds etc at Amazon, B&N etc*
[RIGHT]*Banks, airlines
[RIGHT]*Universities
[RIGHT]*GIS (maps)
[RIGHT]*Www (World Wide Web)
[RIGHT]*Digital libraries
[RIGHT]1-single user
[RIGHT] - supports only one user at a time
[RIGHT]2-desktop
[RIGHT] -Single-user database running on a personal computer
[RIGHT]3-multi-user
[RIGHT] -supports multiple users at the same time
[RIGHT]4-workgroup
[RIGHT] -multi-user database that supports a small group of users or a single department
[RIGHT]5-enterprise
[RIGHT] -multi-user database that supports a large group of users or an entire organization
[RIGHT] To be continued…