INFORMATION MANAGEMENT
Unit 2 SO 4
Explain the advantages of
using a database approach
compared
to
using
traditional file processing;
Advantages including speed, efficiency, cost; data
quality: completeness, validity, consistency,
timeliness and accuracy; data handling, data
processing.
What are Traditional File
Processing systems?
 Traditional file based system is basically a file based
system, in which we manually handle the database
such as updating, inserting, deletion or adding new
files to database, etc.
ADVANTAGES
DISADVANTAGES
•
•
• Need of external storage
No need of highly technical person to
handle the database.
Provide less security.
• Redundancy is high
• Less integrity
• High complexity in updating of
database records
• Processing speed is low.
What is a Database?
Fields
a structured collection
of records or
data that is stored
in a computer system
This represents 1
unit of
information in a
database – e.g.
Title of DVD,
Genre
Records
Contains information relating to 1 item of data in
a DB
What is a Database Management
System (DBMS)?
 is computer software designed for the purpose of
managing databases based on a variety of data models
Security can be
improved
Redundancies can
be improved!
Integrity can be improved
Confidentiality, privacy and
security
Data quality concerns
Advantages
Better services
to users
Disadvantages
Cost of delivering and
maintaining the system is
lowered
Standards can be enforced
Faster response to query processing
Data integrity concerns
Enterprise vulnerability
may be higher
The cost of using DBMS
Database Views
view that the individual user of the
database has
the information model of the enterprise and
contains the view of the whole enterprise
without any concern for the physical
implementation
view about the actual physical storage of
data
Role of Database Administrator
Deciding and Loading the Database
Contents
Assisting and Approving Applications
and Access
Deciding Data Structures
Backup and Recovery
Monitor Actual Usage
INFORMATION MANAGEMENT
Unit 2 SO 5
Describe the different types and
organization of files and
databases;
File types including master and transaction files; file
organization including serial, sequential, random or direct,
indexed sequential database types including personal,
workgroup, department and enterprise databases; database
organization including hierarchical, relational, network and
object-oriented.
Files Types in Database
MASTER FILE
A master file or master table
contains a group of common
records. Item Data, Customer Data,
and Supplier Data are examples of
tables.
Additional
Content
Check this out!
A computer file containing
relatively transient data
about a particular data
processing task
File Access Methods:
Sequential vs. Direct
Serial Access
This means ...start at the
beginning of the file and
access each record
in turn until the one
needed is found.
If files are stored
on magnetic tape
then serial access
is the only method
of access.
Quiz!
Direct Access
The computer can calculate
(from the key field)
where the record is stored
in the file, and can then access
the record directly from that position.
Direct Access can only be used
if files are stored on media such
as disk, CD, DVD. Direct Access
of records will generally be much faster
than Serial Access.
Direct Access is
also known as Random Access.
File Access Methods:
Sequential Access
Sequential Access
A group of elements (e.g. data in a
memory array or a
disk file or on a tape) is
accessed in a
predetermined,
ordered sequence
Personal – used for recording
self information and for
one’s own access. A database
created to store phone
contacts and
addresses and friends
would be a good example.
Workgroup – used by teams
working on tasks
that needs access to the same data.
Departmental - by a unit in an
organization which provides
some functional
application of the
data in the
department’s domain
Enterprise - Centralized data
that is shared by
many users throughout
the organization
Database Organization
NETWORK
DATABASE
HIERARCHICAL
DATABASE
RELATIONAL
DATABASE
OBJECT ORIENTED
DATABASE