Transcript Database Software

Database Software
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File Management Systems
Database Management Systems
Both Groups Contain:
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File Manager
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creating file structure
adding, deleting, or editing records
sorting records
Query Facility
Report Generator
File Management Systems
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Work with one file at a time
Usually cheap and easy to use
Inefficient for relating data in different
files
Example:
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Order File
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customer number
order
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Customer File
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customer number
name
address
Problems with File
Management Systems
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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
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Can combine information from more
than one file
Self-descriptive
Expanded query facilities
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nonprocedural query languages
procedural query languages (SQL)
Data Security
Advantages of Database
Management Systems
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better information
faster response time
lower operating costs
fewer storage requirements
improved data integrity
better data management and security
Disadvantages of Database
Management Systems
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DBMS software is relatively expensive
often requires new hardware
usually requires training to use
Database Management on
Large Computer Systems
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Hierarchical
Network
Relational
Object Oriented
Client Server Systems
Distributed Database Systems
Hierarchical Databases
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first to be developed
stores data in the form of a tree
sets up a one to many relationship
Network Databases
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modification of the tree model
relationship between data elements can
be many to one or many to many
Hierarchical and Network Data
Models
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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
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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
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Can store objects in
a database
object-relational
database
management
systems
Oracle, Access
Client-Server Systems
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Client computers run a desktop DBMS
with a GUI
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Server computer contains and manages
the database itself
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front end - Access, Paradox
back end - SQL Server, DB2
Lower hardware cost
Scalability
Distributed Database Systems
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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