Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Database management systems
Description: This is for 3rd semester MBA students. here we get much simpler form of DBMS acting like a guide for you and making you easier to study and score good marks for your exams.!!
Description: This is for 3rd semester MBA students. here we get much simpler form of DBMS acting like a guide for you and making you easier to study and score good marks for your exams.!!
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Database Mangement
Systems
NJW
1
DATABASE
A database is an organized collection of DATA
...
2
DATA
A collection of facts in raw form that
become information after proper
organization or processing
...
A general‐purpose DBMS is a SOFTWARE
system designed to allow the definition,
creation, querying, update, and administration
of databases
6
File
Collection of related information
8
9
• Vishal Sikka
was a member of the Executive
Board of SAP AG and the Global Managing Board,
heading all SAP products and innovation
...
•
Sikka left the SAP board in May 2014 for "personal
reasons“, and was announced as CEO and MD of Infosys
on 12 June 2014
...
Finacle is a web based banking application
designed with Oracle RDBMS at backend; its
open architecture supports wide range of UNIX
servers
...
11
12
13
Father of The Relational Model
Oxford‐trained mathematician working for IBM @
San Jose Laboratory
In 1970, Codd released “A Relational Model of Data
for Large Shared Data Banks
...
“It provides a means of describing data with its natural
structure only‐‐that is, without superimposing any
additional structure for machine representation purposes
...
”(Codd 1970)
14
RDBMS
Oracle
Postgre SQL
IBM DB2
Dbase
MySQL
SAP HANA
Ingres
MS SQL
MS Access
Visual foxpro
15
16
17
18
19
20
21
Front end tools
Java Script
Developer 2000
CSS cascading style sheet
MySQL
HTML
Oracle
HTML SOLR PHP
CSS
22
Advantage of Database
Approach
1, Program – data Independence
2, Minimal data redundancy
3, Improved data consistency
4, Improved data sharing
5, Increased productivity of application development
6, Enforcement of standards
7, Improved data Quality
8, Improved data accessibility and responsiveness
9, Reduced program maintenance
Key Terms cont
...
number,
Designation
Hours
worked, Pay
rate
Insurance,
Pension
24
Database System: Hardware
Set of physical devices on which a database resides
...
25
Database System: Hardware cont
...
A former systems
administrator for the Central Intelligence Agency
and a counterintelligence trainer at the Defense
Intelligence Agency
28
MP Government ban G‐mail for
official communication
According to the new policy, the government officials can no
longer use services such as Gmail, hotmail or rediffmail for
official purposes, they will be provided with an official e‐mail
service
...
Also, digital certificates will be used for confidential
e‐mails, to ensure their safety
...
29
What is an operating system?
Application
OS
Hardware
31
Database System: Software
A database software includes two types of
software
General‐purpose database management software,
usually called the database management system
(DBMS)
Application software that uses DBMS facilities to
manipulate the database to achieve a specific
business function, such as providing reports or
documents, which can be used by users
...
Application software is generally written standard
programming language such as C, or it may be
written in a language (commonly called a fourth‐
generation language) supplied with the DBMS
...
33
Database System: Software cont
...
34
Data Dictionary/Directory
(Repository)
A subsystem that keeps track of the
definitions of all data items in the database
...
indexes that are used to access data quickly
...
35
Data Dictionary
Definitions of data items in the database
includes:
Elementary‐level data items (fields),
group and record‐level data structures, and
files or relational tables
...
• Some of these properties include data definitions, data
structures and rules or constraints
...
• Metadata allow database designers and users to
understand what data exist, what the data mean
...
37
Metadata
E
...
Data Item
Name Type
Value
Length Min Max Description
Name
ID
Dept
Age
30
9
10
2
Character
Number
Character
Integer
Name
Character 15
Manager Number
9
18
60
Employee Name
Employee No
...
No
...
Name
Mgr
...
No
...
(ID) unique
Manager is an employee of the organisation
38
Database System: People
Two different types of people (users and practitioners)
are concerned with the database
...
g
...
Practitioners
people responsible for the
database system and its
associated application software
...
g
...
40
Components of a Database System
Four components: People, H/W, S/W, Data
Practitioners (analysts and database designers) in consultation with
users identify data needs and design database structures to
accommodate these needs
...
41
Components of a DBS cont
...
The entered data are maintained on hardware media such as disks and
tapes
...
42
Components of a DBS cont
...
Database Management System
Systems software that facilitates the management of a database
...
g
...
45
DBMS cont
...
Data
elements are stored in different
tables made up of rows and
columns
...
46
Components of a DBMS
DATA
DICTIONARY/
DIRECTORY
DBMS
USER
USER
User Query and
Reporting
Facilities
Application
Program
Development
Facilities
PROGRAMMER
Data Dictionary/
Directory
Subsystem
Security and
Integrity
Subsystem
Database Access
Subsystem
DATAB
ASE
PROGRAMMER
47
Data Security
The database is a valuable resource needing protection
...
Authorised users will generally be restricted as to the particular data they
can access and whether they can update it
...
1
2
3
4
Data items
49
Data Integrity
The integrity and consistency of the database
are protected via constraints on values that
data items can have and by backup and
recovery capabilities provided within the
DBMS
...
50
Data Integrity
Backup and recovery are supported by software that automatically logs
changes to the database and provides for a means of recovering the current
state of the database in case of system failure
...
The DBMS provides the physical
mechanisms allowing multiple users to
access a variety of related data quickly
and efficiently
...
Easy‐to‐use query languages allow users to
formulate queries and request one‐time reports
directly from the database
...
53
Data Manipulation
Report generators have more powerful reporting
facilities than those in the query language
...
Tools for screen, menu and report generation
application generators
compilers
data and view definition facilities
55
Application Development
Modern database systems provide language components
that are much more powerful than those of traditional
languages, making the programming process itself
considerably more efficient
...
Personal databases
Workgroup databases
Departmental databases
Enterprise databases
Analytic Databases
Operational Databases
57
Personal Computer Databases
Designed to support one user with a standard alone
PC
...
g
...
58
Workgroup Databases
A relatively small team of people (less than 25) who
collaborate on the same project or application
...
g
...
59
Department Databases
A department is a functional unit of an
organisation
...
Department databases are designed to
support the various functions and
activities of a department
...
g
...
60
Enterprise Databases
An enterprise is one whose scope is the entire
organisation or enterprise
...
E
...
a large health care organisation that operates a group of
medical centre's including hospitals, clinics and nursing
homes
...
An enterprise database does support information needs
from many departments
...
Data warehouse
An integrated decision support database whose content is
derived from the various operational databases
...
Ex data of sales records for past 10 years
Used to analyze marketing strategies in
relationship to demographics
63
Operational Databases
OLTP ( Online Transaction Processing)
Operational databases allow you to modify the data
(add,change or delete data)
This type of databases are usually used to track real‐
time information
Ex
...
B
...
De Silva
|222, Galle Road, Colombo
Name (20 characters)
|
Address (40 characters)
650370690V|Senior Lecturer
NID (10 char) Designation (15 char)
70
Physical View
• Physical view provides the disk drives,
physical addresses, indexes and pointers
...
No user is concerned
with this view
...
B
...
De Silva
Designation Senior Lecturer
Address
222, Galle Road, Colombo
72
Logical View
• This is a single logical description of all
data elements and their relationships
...
• SQL CREATE TABLE statement is
used to define the data elements
...
B
...
De Silva
Department
Dept
...
• Each definable user group will have its
own view of the database
...
75
User View
• A logical description of some portion of
the database that is required by a user
to perform some task
...
g
...
76
External View
• It can be derived directly from the
conceptual schema
...
• SQL CREATE VIEW statement is used
to create these views and SQL GRANT
statement is used to restrict its use to a
user group
...
• External Views Allows to
– hide unauthorised data
e
...
salary, dob
– provide user view
e
...
view employee name, designation,
department data taken from employee and
department files
– derive new attributes
e
...
age derived from dob or nid
78
External View cont
...
g
...
g
...
External
Conceptual
Conceptual Physical
• Database exists in reality only at the
internal level
...
• Sub-Schema Data Definition Language
(SDDL)
- is the language component of a DBMS
that defines data elements as it should
appear to the end users and
programmers
...
• Structured Query Language (SQL)
- pronounced as sequel, is the standard
data manipulation for relational DBMSs
...
Main Functions are:
Shared data
Control redundancy
Data integrity
Data security
88
Capabilities of a DBMS
Capabilities vary considerable, but basic operations are:
Data definition
Data entry
Data manipulation
Data display
89
Database Approach
Advantages
•
•
•
•
•
•
•
•
•
Program-data independence
Minimal data redundancy
Improved data consistency
Improved data sharing
Increased productivity of application
development
Enforcement of standards
Improved data quality
Improved data accessibility and responsiveness
Reduced program maintenance
90
Program-Data/Data Independence
• The separation of data descriptions
(metadata) from the application programs
that use the data
...
This property allows an
organisation’s data to change and evolve
(within limits) without changing the
application program that process the data
...
Each primary fact is
recorded (ideally) in only one place in the
database
...
g
...
Note: Data redundancy is not eliminated
entirely
...
g
...
) to
represent the relationship with others
...
E
...
employee address is stored only once
and hence we cannot have disagreement
on the stored values
...
93
Improved Data Sharing
• A database is designed as a shared
corporate resource
...
E
...
employee data common to payroll,
benefit applications will be shared
among different users
...
– Programmer could concentrate on the
specific functions required for the new
application, without having to worry about
design or low-level implementation details;
as related data have already been designed
and implemented
...
– DBMS provides a number of high-level
productivity tools such as forms and report
generations and high-level languages that
automate some of the activities of database
design and implementation
...
– Standards include naming conventions, data
quality standards and uniform procedures for
accessing, updating and protecting data
...
97
Improved Data Quality
A number of tools and processes are available to
improve data quality
...
– One of the objectives of a data warehouse
environment is to clean up operational data
before they are placed in the data warehouse
...
98
Improved Data Accessibility
and Responsiveness
With relational database, end users without
programming experience can often retrieve and
display data, even when it crosses traditional
departmental boundaries
...
99
Reduced Program
Maintenance
Stored data are changed frequently for
variety of reasons such as new data items
types are added, and data formats change
(e
...
date format from two-digit to four
digit)
...
100
Database Approach
Disadvantages
• DBMS are more vulnerable than file-based
system because of the centralised nature of
a large integrated database
...
• Hardware, software and personnel cost are
higher for DBMS
Title: Database management systems
Description: This is for 3rd semester MBA students. here we get much simpler form of DBMS acting like a guide for you and making you easier to study and score good marks for your exams.!!
Description: This is for 3rd semester MBA students. here we get much simpler form of DBMS acting like a guide for you and making you easier to study and score good marks for your exams.!!