Transcript Chapter 2: Introduction to Microprocessor

Definition
 Components
 Advantages
 Limitations
Definition

Components
 Advantages
 Limitations
 Objectives
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Contents
Definition
It is a computer based record keeping system whose overall
purpose is to record & maintain the information. In other
word, database system is a pool (reservoir) of data.
It is composed of collection of files that are linked in such a
way that information from one of the files may be combined
with information from other files so that a user may receive
the exact required information.
Definition Contd..
It is well organized collection of data that are related in a
meaningful way which can be accessed in different
logical orders that re stored only once.
Users
Database
Users
DBMS
Components of Database
Data
 Hardware
 Software
 Users
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Data
Hardware
Software
Users
Data
It refers to values physically recorded in the database. Data
stored in the system is partitioned into two or more files.
But in general, data is integrated & shared.
Integrated means that database may be thought of
unification of several distinct files without any duplicacy.
Data Contd…
Shared means individual piece of data may be shared
between different users in the sense that each user may
access the data. Concurrent sharing is also possible i.e.
several users can access same data simultaneously at same
time in different ways.
Hardware
It consists of secondary storage devices like tape,
disk etc. in which data is actually stored. It also
consists of control unit and Input / output devices.
Software
Between the physical database itself and users of the
system there is a layer of software called DBMS. All
requests from the users are handled by DBMS. In
other word, DBMS protects the user from hardware
level details.
Users
Application Programmers
 End Users
 DBA (Database Administrator)
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Users Contd..
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Application Programmer :
It writes the programs in some programming
language to use the database. These programs
operate the data in all the ways i.e. creating new
information, deleting or changing existing
information, retrieving information.
Users Contd..
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End Users :
The users who uses the programs written by
programmer to work with database system. A end
user may use query language or written program to
issue a request.
Users Contd..
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DBA :
A DBA is a person or group of persons responsible
for overall control of database system. A DBA may
perform functions like deciding information contents,
deciding storage structure & access strategies,
defining strategies of backup & recovery etc.
Advantages of Database
System
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Redundancy can be removed
Inconsistency can be avoided
Data can be shared
Standards can be easily enforced
Integrity can be maintained
Conflicting requirements can be balanced
Data Independence is there
Limitations of Database
System
Security Problem
 Privacy Problem
 Sophisticated Software is required
 High speed I/O devices are required
 Sophisticated backup procedure is required
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Objectives of Database
System
There should be centralized control
 Redundancy should be avoided
 Inconsistency should be avoided
 System should be easy to use
 Standards should be enforced
 Data should be sharable
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Objectives Contd..
Conflicting requirements should be balanced
 User’s requirements should be fulfilled
 Security should be provided
 Privacy should be provided
 Data Independence should be there
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Points to think……
Difference between Database & Database
System
 Difference between Advantages & Objectives
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Thank You