dbms

1. Day 1 Class/
Orientation
WELCOME TO AI&DS DEPARTMENT

2. Overview of Syllabi: Module 1

3. Module 2

4. Module 3

5. Module 4

6. Module 5

7. Text book (Recommended)
Fundamentals of Database Systems (Seventh Edition)
Author: Ramez Elmasri and Shamkant Navatne
Advantages: 1. Syllabi and text book content go hand in hand
2. Good practical datasets given
3. Link to softcopy released by authors:
https://www.auhd.site/upfiles/elibrary/Azal2020-01-22-12-28-11-76901.pdf

8. Course outcomes of DBMS

9. WHAT EXACTLY IS A DATABASE

10. Introduction to DataBase Systems
1. Definitions
2. Database management system –Definition and functionalities
3. Properties of Database
4. A simplified Database System Environment
Example of University Database

11. Slide 1-11
Basic Definitions
Database: A collection of related data.
Data: Known facts that can be recorded and have an implicit meaning.
Mini-world: Some part of the real world about which data is stored in a
database. For example, student grades and transcripts at a university.
Database Management System (DBMS): A software package/ system to
facilitate the creation and maintenance of a computerized database.
Database System: The DBMS software together with the data itself.
Sometimes, the applications are also included.

46. Slide 1-46
Typical DBMS Functionality
Define a database : in terms of data types,
structures and constraints
Construct or Load the Database on a
secondary storage medium
Manipulating the database : querying,
generating reports, insertions, deletions and
modifications to its content
Concurrent Processing and Sharing by a set
of users and programs – yet, keeping all data
valid and consistent

47. Slide 1-47
Typical DBMS Functionality
Other features:
◦ Protection or Security measures to prevent unauthorized access
◦ “Active” processing to take internal actions on data
◦ Presentation and Visualization of data

48. Slide 1-48
Example of a Database
(with a Conceptual Data Model)
Mini-world for the example: Part of a UNIVERSITY
environment.
Some mini-world entities:
◦ STUDENTs
◦ COURSEs
◦ SECTIONs (of COURSEs)
◦ (academic) DEPARTMENTs
◦ INSTRUCTORs
Note: The above could be expressed in the ENTITY-
RELATIONSHIP data model.

49. Slide 1-49
Example of a Database
(with a Conceptual Data Model)
Some mini-world relationships:
◦ SECTIONs are of specific COURSEs
◦ STUDENTs take SECTIONs
◦ COURSEs have prerequisite COURSEs
◦ INSTRUCTORs teach SECTIONs
◦ COURSEs are offered by DEPARTMENTs
◦ STUDENTs major in DEPARTMENTs
Note: The above could be expressed in the ENTITY-RELATIONSHIP data
model.

50. Slide 1-50
Main Characteristics of the
Database Approach
Self-describing nature of a database
system: A DBMS catalog stores the
description of the database. The description
is called meta-data). This allows the DBMS
software to work with different databases.

51. Figure 1.2
A database that stores student and course
information.

55. Figure 1.3
An example of a database catalog for the database in Figure 1.2.

58. Slide 1-58
Main Characteristics of the
Database Approach
Insulation between programs and data:
Called program-data independence.
Allows changing data storage structures
and operations without having to change
the DBMS access programs.

59. Slide 1-59
Main Characteristics of the
Database Approach
Data Abstraction: A data model is used to
hide storage details and present the users
with a conceptual view of the database.
Support of multiple views of the data:
Each user may see a different view of
the database, which describes only the
data of interest to that user.

60. Figure 1.5
Two views derived from the database in Figure 1.2. (a) The TRANSCRIPT view.
(b) The COURSE_PREREQUISITES view.

62. Slide 1-62
Main Characteristics of the
Database Approach
Sharing of data and multiuser transaction
processing : allowing a set of concurrent users to
retrieve and to update the database. Concurrency
control within the DBMS guarantees that each
transaction is correctly executed or completely
aborted. OLTP (Online Transaction Processing) is a
major part of database applications.

63. Next Topic
ADVANTAGES OF USING THE DATABASE APPROACH

64. Slide 1-64
Advantages of Using the
Database Approach
Controlling redundancy in data storage and in development and maintenance efforts.
Sharing of data among multiple users.
Restricting unauthorized access to data.
Providing persistent storage for program Objects
Providing Storage Structures for efficient Query Processing

65. Slide 1-65
Advantages of Using the Database
Approach
Providing backup and recovery services.
Providing multiple interfaces to different classes of users.
Representing complex relationships among data.
Enforcing integrity constraints on the database.
Drawing Inferences and Actions using rules

66. Slide 1-66
Additional Implications of Using
the Database Approach
Potential for enforcing standards: this is very
crucial for the success of database applications
in large organizations Standards refer to data
item names, display formats, screens, report
structures, meta-data (description of data) etc.
Reduced application development time:
incremental time to add each new application
is reduced.

67. Slide 1-67
Additional Implications of Using
the Database Approach
Flexibility to change data structures: database
structure may evolve as new requirements are
defined.
Availability of up-to-date information – very
important for on-line transaction systems such as
airline, hotel, car reservations.
Economies of scale: by consolidating data and
applications across departments wasteful overlap
of resources and personnel can be avoided.

68. Next Topic
HISTORICAL DEVELOPMENT OF DATABASE TECHNOLOGY

69. Slide 1-69
Historical Development of
Database Technology
Early Database Applications: The
Hierarchical and Network Models were
introduced in mid 1960’s and dominated
during the seventies. A bulk of the worldwide
database processing still occurs using these
models.
Relational Model based Systems: The model
that was originally introduced in 1970 was
heavily researched and experimented with in
IBM and the universities. Relational DBMS
Products emerged in the 1980’s.

72. Slide 1-72
Historical Development of
Database Technology
Object-oriented applications: OODBMSs were
introduced in late 1980’s and early 1990’s to cater
to the need of complex data processing in CAD
and other applications. Their use has not taken
off much.
Data on the Web and E-commerce
Applications: Web contains data in HTML
(Hypertext markup language) with links among
pages. This has given rise to a new set of
applications and E-commerce is using new
standards like XML (eXtended Markup
Language).

74. Chapter 1 Ends

75. Database management system –
Definition and functionalities
Definition:-Collection of programs that enables users to create and maintain the database.
Functionalities:-
Define:-Specifying the data type, structures and constraints for the data to be stored.
Construct:-Process of storing data on some storage medium
Manipulate:-Querying the database to retrieve specific data, updating database and
generating reports.
Share:-Allows multiple users and programs to access the database concurrently.

76. Properties
1. A database represents some aspects of the real world
2. A database is a logically coherent collection of data with some inherent meaning
3. A database is designed, built and populated with data for a specific purpose

77. Case Scenario 1: Mobile Phone
In the world when everyone around us have mobile phone, storing of contacts becomes a
key component.
Fields while storing a contact includes:
Names (First Name, Middle Name, Last Name)
Contact Number (1st
contact number, 2nd
contact number etc)
Email Address
For companies, URL of website and fax number become key details

78. Snippet of the various fields while creating
contact

79. Advantages:
You can now ask questions such as “Show me all my contacts who
work for this particular organisation
live in this city
Have birthday on October 19th
OR a question like:
"I am visiting Mysore; for each education organisation in that city, show me contacts
who's birthday is coming up in the month of November"

80. Layman’s insight to database
Data is unit of information and database is the container for holding
the data.
Scenario 1: Book is database whereas the individual chapters
become data.
Scenario 2: Library is database whereas the book becomes data.
Scenario 3: University is database whereas library becomes data.

81. Scenario 2: Library is database
whereas the book becomes data.
Lending of book is a basic functionality of library.
Key Aspect: Readers being able to search particular book efficiently.
How to achieve: Organization of the books (data) in the form of
labelled racks, book shelves, drawers etc.
Library is indeed a real-world database as it involves organizing of
data in the form of books for effective retrieval of knowledge.

82. Q. Is RAM (Random Access
Memory) a database?
Absolutely, YES!!
Here, byte (8 bits of information) is the data unit.
Data in the form of byte/s need to be organized and stored as an
array.
Objective of random access in an array storage shall be achieved.
RAM is an example of Hardware database

83. Q. Is Harddisk a database?
YES!!
Blocks of data in the form of various kinds of files is the data unit.
Objective of storage organization facilitating quick location of Files and
stuffs, just like file cabinet.
Can we pool in RAM and Hard-disks separately to create a bigger
database?
Indeed yes!

84. Q. What probably is MySQL?
A good container for data with lot of relations.
Data is organized in such a way, so that we can ask pretty tough
questions to it.
E.g Tell me the names of all males who are between ages 20 to 30,
and love database?