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Database Software File Management Systems Database Management Systems Both Groups Contain: File Manager creating file structure adding, deleting, or editing records sorting records Query Facility Report Generator File Management Systems Work with one file at a time Usually cheap and easy to use Inefficient for relating data in different files Example: Order File customer number order Customer File customer number name address Problems with File Management Systems data redundancy - repetition of the same data in different files data integrity - errors caused by differences in redundant data data dependence - files are dependent on hardware or software Database Management Systems Can combine information from more than one file Self-descriptive Expanded query facilities nonprocedural query languages procedural query languages (SQL) Data Security Advantages of Database Management Systems better information faster response time lower operating costs fewer storage requirements improved data integrity better data management and security Disadvantages of Database Management Systems DBMS software is relatively expensive often requires new hardware usually requires training to use Database Management on Large Computer Systems Hierarchical Network Relational Object Oriented Client Server Systems Distributed Database Systems Hierarchical Databases first to be developed stores data in the form of a tree sets up a one to many relationship Network Databases modification of the tree model relationship between data elements can be many to one or many to many Hierarchical and Network Data Models less data redundancy than relational model fast data access for predefined queries good security useful for transaction processing environments not very flexible - designed for speed Relational Database Model based on tables of data objects designed for flexibility useful for decision support slower processing times and less security than other two models Object Oriented Database Can store objects in a database object-relational database management systems Oracle, Access Client-Server Systems Client computers run a desktop DBMS with a GUI Server computer contains and manages the database itself front end - Access, Paradox back end - SQL Server, DB2 Lower hardware cost Scalability Distributed Database Systems database is divided among several smaller computers that are hooked up in a client-server form of a network data is stored at most needed site all clients on the network can access any part of the database