Download DATA - DAV College For Girls, Yamunanagar













TERMINOLOGY
DATA
INFORMATION
NEED OF INFORMATION
QUALITIES OF INFORMATION
FILE SYSTEM APPROACH
LIMITATION OF FILE SYSTEM APPROACH
DATABASE SYSTEM
DATABASE SYSTEM ENVIRONMENT
COMPONENTS OF DATABASE SYSTEM
WHY STUDY DATABASES
DATABASE MANAGEMENT SYSTEM(DBMS)
FUNCTION OF DBMS
STRUCTURE OF DBMS

It is a collection of meaningful facts which can be stored and processed by
computers or humans. Ex Price, Phone no, addresses etc.

In terms of computing, data is defined as collection of facts that has been
translated into the form that is more convenient to analyze or to do further
calculation.

Data can be represented in the form of:
Sounds
Images
Segments
Words
DATA
Numbers
BACK

Information is defined as the processed data which helps us in making
decisions.

It is the intelligent form of data.

For Example:pay check, timetable, reports, merit list, bills etc.

The information is obtained by arranging data into meaningful form.

For Example:Marks obtained by students and their roll numbers form the data and their
report card is the information which help us to make decision, which student
stood at what rank in the class.
BACK

Information is necessary for the people of the modern world because without
proper information, it is very difficult to survive in the modern world.

One should keep himself aware of all the changes occurring in the society.

To keep the system up to date we need to gather information from various
sources like television, internet, newspaper, radio, magazines etc.
BACK





Must be meaningful
Must be accurate and clear
Should convey to the point relevant information
Should confirm and correct the previous knowledge
Should reach at proper time such that proper action is taken
BACK

To computerize the manual way of storing data in the database was File
System approach.

It is basically a collection of application programs that perform services to
the end users

A file is a collection of records which contains logically related data known
as fields

Multiple user access to the information is difficult to provide. This is due to
poor coordination of application program.
BACK








Data redundancy and inconsistency
Data dependence
Difficulty occur to get quick answers to simple queries
Lack of data integrity and quality
Difficult to share data
Transaction problem
Lack of security
Concurrency problems
BACK
Database:
A very large, integrated collection of data.


A Database is a well organized collection of data that are related in a
meaningful way which can be accessed in different logical orders but
are stored only once
The record of students maintained by your college is a useful database
Models a real-world enterprise
◦ Entities (e.g., teams, games)
Related to
each other
data1
data1
organized
Database
database
BACK
DATA BASE SYSTEM ENVIRONMENT
Database
System
Stored data
base
definitoin
(META DATA)
DBMS
S/W
Stored
Database
BACK

The database system contains not only the database itself but also a complete
definition or description of the database structure and constraint. This
definition is stored in the system catalog.

The information stored in the catalog is called metadata that is the “data about
the data”

An important property of database system is that the structure of data files is
stored in the DBMS catalog separately from the access program.
We call this property as program-data-independence .
Due to this property we can change the structure of data files in the
catalog but no need to change the programs.
The Purpose of the database system is to provide an environment that
is both convenient an efficient to use in


Retrieving information from the database
Storing information into the database
BACK

DATA
User data
Meta data
Application meta data

HARDWARE

SOFTWARE

USERS
BACK
Data:The data act as a bridge between the machine part and the user which directly
access it or access it through some application program. Data may be of different
types:
User Data:- It consist of a table of data called relation where columns are
called fields and rows are called records.
Meta Data:- A description of the structure of the database is known as meta
data. it basically means “data about data”.
Application Meta Data:- It stores the structure and format of queries, reports
and other application components.
HARDWARE:In order to run the DBMS and applications, hardware is required. The
hardware consist of the secondary storage device such as magnetic disks
and optical disks on which data is stored together..In addition , it includes
the I/O devices, processor and maim memory etc. which are used for
storing & retrieving the data in fast & efficient manner. Proper care should
be taken for choosing the appropriate hardware for a required database.
SOFTWARE:The software part consist of DBMS which act as a bridge between the user
& the database. In addition to DBMS SOFTWARE, it also includes the
application programs, the operating system..Using these software, the users
interact with the database.
USER:User are those person who need information from the database to carry out
their primary business responsibilities i.e. Personnel, staff clerks,
Managers, Executives etc. On the basis of the job and requirements made
by them, they provided access to the database totally or partially.
The various type of users which can access the database are




Database Administrator(DBA)
Database Designer
End Users
Casual End Users
Naïve End Users
Standalone End Users
Application Programmers
BACK
?



Shift from computation to information
◦ always true for corporate computing
◦ Web made this point for personal computing
◦ more and more true for scientific computing
Need for DBMS has exploded in the last years
◦ Corporate: “customer relationship mgmt”, “supply chain mgmt”,
“data warehouses”, etc.
◦ Scientific: digital libraries, Human Genome project, NASA Mission
to Planet Earth, physical sensors, grid physics network
DBMS encompasses much of CS in a practical discipline
◦ OS, languages, theory, AI, multimedia, logic
◦ Yet traditional focus on real-world apps
BACK
DBMS is the collection of programs which act as an intermediates
between the user and the database
DBMS is the software that interprets and processes user’s request to
retrieve information from a database
DBMS provides security facilities in a variety of forms, both to prevent
unauthorized access and to prevent authorized users from accessing
data concurrently without any inconsistency in the database
The primary purpose of a DBMS which is basically a collection of
programs is to allow a user to store, update, retrieve data.
BACK


Data Definition
DBMS must be able to access data definition in source
form and convert them to the appropriate object form. In other words
DBMS must include language processor component for each of the
various data definition language(DDL).
Data Manipulation
DBMS must include a DML processor component.
The DBMS must be able to handle request from the user to see,
retrieve, update , delete or add the new record to the database.
t


DATA SECURITY AND INTEGRITY
DBMS must monitor user request &
reject any attempt to violate the security & integrity rules define by the
DBA.
DATA DICTIONARY
The dictionary contains data about the data rather
than the raw data.
Data Dictionary contains the information about entities, attributes,
mapping etc.
DBMS should perform all the functions as efficiently as possible.
BACK



A typical DBMS has a layered
architecture.
The figure does not show the
concurrency control and recovery
components.
Each database system has its own
variations.
These layers
must consider
concurrency
control and
recovery
Query Optimization
and Execution
Relational Operators
Files and Access Methods
Buffer Management
Disk Space Management
DB
BACK
BACK