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 front end - Access, Paradox Server computer contains and manages the database itself 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