Database Management System
Prerequisites :

Fundamentals of Programming
Course Objectives:

To understand the fundamental concepts of database management

To provide a strong formal foundation in database concepts, technology

To give systematic database design approaches covering conceptual design, logical design
and an overview of physical design

To learn basic issues of transaction management and concurrency control

To learn and understand various Database Architectures and Applications

To learn a powerful, flexible and scalable general-purpose database to handle big data
Course Outcomes:

Demonstrate programming fundamental using python language.

Apply object-oriented programming concept using python language.

Make use of data structure and algorithm using python language.


Build MYSQL database connectivity with python for Database navigation operations
such as select, create, insert, delete, update.
Demonstrate programming fundamental using python language.
Units:

Unit I: Introduction to DBMS

Unit II: Relational Algebra, SQL and PL/SQL

Unit III: Relational Database Design

Unit IV: Database Transactions and Query Processing

Unit V: Database architecture

Unit VI: Advances in Databases and Big Data
Units:


Unit I: Introduction to DBMS
Introduction to Database Management Systems, Advantages of a DBMS
overfile-processing Systems, Database-System purpose and applications,
Levels of Database Systems, Database Languages, Data Models, Components
of a DBMS and overall structure of a DBMS, Database Design and ER Model:
Entity, Attributes, Relationships, Constraints, types of Keys, Design Process,
Entity Relationship Model, ER Diagram, Design Issues, Extended E-R Features,
converting E-R & EER diagram into tables.
Introduction to DBMS:

What is DBMS

Why DBMS

Advantages of a DBMS overfile-processing Systems
What is DBMS?
DBMS consist of two parts
Database and
Management System
Data is the basic building block of any DBMS
Data
- Data can be anything like name,age,address,contact no, etc.
- Facts, figures, statistics etc. having no particular meaning
For Example : 5,ABC,Pune,etc.
Record
- Collection of related data items
For Example : 5,ABC,Pune,19,etc.
- No meaning to the data items mentioned above
- It is raw and unorganized, that need to processed to make it meaningful as mentioned
below
Roll Number
Name
City
Age
5
ABC
Pune
19
Table
- Collection of related records
Roll Number
Name
City
Age
5
ABC
Pune
20
9
XYZ
Pune
18
3
LMN
Pune
19
Database:
- Database can be access at different levels with their own customized front-end
application.
e.g. Faculties of different departments will have different levels of access
Database:
- Data is organized strictly in row and column format in In a database.
- The rows are called Tuple or Record and the columns are called Domain or Attribute.
Note : The data items within one row may belong to different data types.
All the data items within a single columns are of the same data type.
Database-management system (DBMS):
- DBMS Can be defined as
->collection of interrelated data
->Set of programs to access those data
- interrelated data have some implicit meaning hence it is called as database.
- The collection of data is called database.
Importance of management system
- The database can be maintain with some kind of rules.
e.g.
- Common attributes to create relationship between two tables
- Easily insertion and deletion of records
- etc.
All these issues can be resolved by having some kind of rules to maintain the integrity of
the database.
Purpose Of DBMS
- DBMS helps users to create, insert, retrieve and update the information contained in the
database as per the requirement .
- Information can be of an individual, school, college,etc.
Applications Of DBMS
- Below mentioned are few applications of DBMS
1. College Management System
2. Banking
3. Online Shopping
etc
front-end and back-end
Front-end : what the user can see
Back-end : supports front -end
Front -end and Back-end both are necessary to develop application.
Front-end : user interface
Back-end : means the server, application and database.
front-end and back-end
Back-end : it can be called as server side, it provides data on request and it also contains
the database.
front-end and back-end
Back-end Tools :
Databases like Oracle, Microsoft SQL Server, IBM DB2, MySQL, NoSQL and PostgreSQL
useful to develop backend
Levels of Database Systems
Levels of Database Systems
Physical Level :
It is also called as Internal View.
The lowest level of abstraction describes how the data are actually stored.
It also describes complex low-level data structures in detail.
In this level data is stored in the external hard drives i.e. data is stored in files and folders.
Actual physical storage structure and access paths can be describe with the help of this level.
Levels of Database Systems
Conceptual Level :
It is also called as logical level.
It is the next-higher level of abstraction describes what data are stored in the database
It also describes what relationships exist among those data.
It describes how the database appears to the users conceptually and the relationships between various
data tables.
Defines all database entities, their attributes, and their relationships
Programmers and database administrators work at this level.
Levels of Database Systems
External Level :
It is also called as View level.
The highest level of abstraction describes only part of the entire database.
The external level only shows the relevant database content to the users in the form of views and hides
the rest of the data.
So different users can see the database as a different view as per their individual requirements.
External schema level is nearest to the user
Database Languages
Database languages can be used to read, store and update the data in the database.
Data Models
Data models define how data is connected to each other and how they are processed and stored inside the
system.
A Data model provides a way to describe the design of a database at the physical, logical, and view levels.
1)Relational Data Model
2)Entity-Relationship Data Model
3)Object-based Data Model
4)Semistructured Data Model
Relational Data Model
The data in this model is in the form of rows and columns within a table.
This model uses tables for representing data and in-between relationships.
Tables are also called relations.
This model uses a collection of tables to represent data as well as the relationships among those data.
Each table has multiple columns, and each column has a unique name.
Each table contains records of a particular type with fixed number of fields, or attributes.
The relational data model is the most widely used data model
Data is stored in tables called relations.
Database
Stud
_id
Nam
e
City
Age
5
ABC
Pune
19
9
3
XYZ
LMN
Pune
Mumb
ai
18
19
Stud_id
Name
Div
5
ABC
A
9
XYZ
B
3
LMN
A
DIV
Year
A
FY
B
A
SY
SY
Database
Stud_id
Name
Div
5
ABC
A
9
XYZ
3
LMN
DIV
Year
A
FY
B
B
SY
A
A
SY
Database
Stud_id
Name
Div
Year
5
ABC
A
FY
9
XYZ
B
SY
3
LMN
A
SY
Entity-Relationship Data Model
An ER model is the logical representation of data as objects and relationships among them.
These objects are known as entities, and relationship is an association among these entities.
A set of attributes describe the entities.
For example, Emp_name, Emp_id describes the 'Emp' entity.
Set of the same type of entities is known as an 'Entity set', and
Set of the same type of relationships is known as 'relationship set'.
The entity-relationship (E-R) data model uses a collection of basic objects, called entities, and relationships among
these objects.
Object-based Data Model
It is an extension of the ER model with notions of functions, encapsulation, and object identity, as well.
This model supports a rich type system that includes structured and collection types.
object-oriented data model that can be called as extending the E-R model as it contains encapsulation,methods
and identity of object.
Combination of object-oriented data model and relational data model called object- relational data model.
Semistructured Data Model
Semi-structured data model consist of specification of data where individual data items of the same type may have
different sets of attributes.
The Extensible Markup Language (XML) is used to represent semi-structured data.
Components of DBMS
Components of DBMS :

Software

Hardware

Procedures

Data

Users
Components of DBMS
Software :
The primary aspect of a DBMS is the software.
Software is the set of programs used to manage the database
Software in DBMS is used to store, retrieve, and update data in the database.
Software is capable of understanding the database language and which runs the commands into the
database.
Components of DBMS
Hardware :
Hardware components includes computer, I/O channels for data, hard disks.
Hardware components is mainly used for keeping and storing the data in the database.
Components of DBMS
Procedures :
This component consist of set of instructions and rules to apply a database management system
It is used to setup and install database management system
It also consists methods to setup to login logout of the DBMS, maintain backups, handle database
and also to guide users for operating the databases, etc.
Components of DBMS
Data :
One of the most important component of the database management system.
Important task of DBMS is to process the data, in DBMS data is stored, retrieved, and updated to and from the
databases.
Components of DBMS
Users :
Person who control and manage the databases
Below mentioned are the different types of users in DBMS
Application Programmers : writes the application programs to interact with databases
Database Administrators : who manages the overall DBMS
End-Users : who interact with the DBMS to perform various operations using the different types of
commands such as insert, update, retrieve, and delete, etc.
Database Design – (ER) Modeling
Below mentioned are the Database Design Techniques.
ER Modeling
Normalization
ER Modeling
ER model : Entity-Relationship model.
It is a technique for organizing the data independent of the actual database implementation
ER model is used to define the data elements and relationship for a specified system.
ER model very simple and easy to design view of data can develop.
Entity
Entity :
Entity has an independent existence
Entity is anything for which we collect data.
Rectangle is used to represent Entity
Student
Entity
Entity instance :
It is particular member of the entity type.
Example for entity instance : A particular student
Entity
Regular Entity :
Consist of its own key attribute
Example for entity instance : A particular student
Entity
Weak entity :
An entity which depends on other entity for its existence
Weak entity doesn't have any key attribute of its own
In ER diagram double rectangular box is use to represent weak entity
Attributes
Properties which defines entity called Attribute
For example : Id, Name, Age
Oval is use to represent attribute in ER diagram
Attribute
Key attribute
The attribute which uniquely identifies every entity instance is called key attribute
For Example : Student_id
oval with underlying lines is used to represnt key attribute
Student_id
Simple attribute
The attribute that can not be divided into simpler components is called Simple attribute.
For Example : Student_id,Student_Name
Composite attribute
Attribute that can be split into components called as composite attribute.
For Example : Address
Address
City
State
Single valued Attributes
The Attribute that can take only a single value for each entity instance called as Single
valued attribute
For Example : Student_age
Multi-valued Attributes
The attribute that can take more than one value for each entity instance called as multivalued attribute.
For Example : Student_Contact_No
Stored Attribute
The attribute that need to be stored permanently is called stored attribute
For Example : Student_Name
Derived Attribute
When value of an attribute can be calculated based on other attributes is called derived
attribute.
For Example : Student_age can be calculated from DOB and Current date
Relationships
Interrelation between entities are called relationships
For Example : Teacher teaches to student
Here teaches is a relation between the entities Teacher and Student
Teacher
Teaches
Student
Relationships
Relation of Weak Entity with other entities can be represent with the help of below
mentioned symbol
Relationships
Relation of Weak Entity with other entities can be represent with the help of below
mentioned symbol
Cardinality of a Relationship
Mapping Cardinality : It is the number of entities to which another entity can be
associated via a relationship set which can have four possible connectivities as given
below :
One to one relationship
One to many relationship
Many to one relationship
Many to many relationship
Cardinality of a Relationship
One to One relationship
For Example : One faculty Cabin is allotted to One Faculty
It is a 1:1 relationship
cardinality is One-To-One (1:1)
Cardinality of a Relationship
One to One relationship in ER modeling
Cardinality of a Relationship
One to many relationship
For Example : One department can have many faculties, .
Hence it is a 1:N relationship
and cardinality is One-To-Many
Cardinality of a Relationship
One to Many relationship in ER modeling
Cardinality of a Relationship
Many to One relationship
For Example : One faculty works in only one college But one college can
have many faculties. Hence it is Many-to-One relationship.
Cardinality of a Relationship
Many to One relationship in ER modeling
Cardinality of a Relationship
Many to Many relationship
For Example : One student can select multiple subject and One subjects can be enrolled
by many students.
Hence it is a M:N relationship and cardinality is Many-to-Many
Cardinality of a Relationship
Many to Many relationship in ER modeling
Relationship Participation
Relationship Participation
1. Total
In this type of participation each entity instance will be connected through each entity instance through the
relationship.
2. Partial
Example for relationship participation.
Consider the relationship - Faculty is head of the department. All the faculties will not be the head of
the department. Only one faculty will be the head of the department.
Advantages and Disadvantages of ER Modeling
Advantages :
- Simple and easily to understand.
- It is use to describe design of database.
- Can be generalized and specialized as per the requirnments
Disadvantages :
- No industry standard for notation
- Limited relationship representation
Constraints in DBMS
- Constraints plays important role to ensure the correctness of data in the database
- Constraints are the restrictions on the database
Types of Relational Constraints :

Domain Constraint

Key Constraint

Entity Integrity Contstraint

Referential Intergrity Constraint

Domain Constraint
- It defines valid set of values or domain values for an attribute and the value of the attribute
must be available in the corresponding domain.
- For Example :
In Name Column values “ 33 ”
Not allowed as it is integer value
And name is string value.
Stud_id
Name
City
Age
5
ABC
Pune
19
9
XYZ
Pune
18
3
33
Pune
19
Key Constraint
- To identify an entity uniquely from entity set of entity, keys are the entity set which are used.
- Multiple keys can be available with entity set.
- Primary key must be unique
Table 2
Table 1
Stud_id
Name
City
Age
Stud_id
Name
City
Age
5
5
9
9
3
3
ABC
ABC
XYZ
XYZ
LMN
LMN
Pune
Pune
Pune
Pune
Pune
Pune
19
19
18
18
19
19
5
ABC
Pune
19
5
XYZ
Pune
18
3
LMN
Pune
19
Primary Key
In Table 2 relation does not satisfy the key constraint since all
the values of primary key are not unique.
Stud_id : 5 for 2 records
Entity Integrity Constraint
- Entity integrity constraint says that primary key value can't be null.
- As the use of primary key value is to identify individual record, if the primary key contains NULL
value, then we can't identify those records.
Stud_id
Name
City
Age
5
ABC
Pune
19
9
XYZ
Pune
18
LMN
Pune
19
NULL
Does not satisfy the entity integrity constraint
Referential Integrity Constraint
- A referential integrity constraint is in between two tables.
- It says that if a foreign key in Table 1 refers to the Primary Key of Table 2, then every value of the Foreign Key
in Table 1 must be null or be available in Table 2.
Referential Integrity Constraint
Stud_Id
Name
Div
Dept_Id
1
ABC
B
1
2
XYZ
B
2
3
LMN
B
5
Primary
Key
Primary Key
Foreign Key
It does not satisfy Referential Integrity Constraint
Relationship
Dept_Id
Dept_Name
College_Name
1
AI and DS
VIIT
2
Computer
VIIT
3
IT
VIIT
Keys
- Key is used to uniquely identify any record present in the table.
- A DBMS Key can be an attribute or a set of attributes which helps to identify a record of a table.
For Example :
Stud_id
Name
PRN
Age
1
Prashant
121
19
2
Ritesh
122
18
3
Vivek
123
21
4
Prashant
124
25
5
Rahul
125
23
- Key can also used to establish and identify relationships between tables.
Keys
Types of key:
- Primary key
- Candidate key
- Super Key
- Foreign key
Keys : Primary Key
Primary key :
- Primary key is used to identify one instance of an entity uniquely.
- Table can have multiple keys, the key which is most suitable from those lists become a primary key.
- Selection of primary key in table is completly based on requirement and developers.
For example :
Primary Key
Stud_id
Name
PRN
Age
1
Prashant
121
19
2
Ritesh
122
18
3
Vivek
123
21
4
Prashant
124
25
5
Rahul
125
23
Keys : Candidate Key
Candidate key :
- It is an attribute or set of an attribute that can uniquely identify a tuple.
Candidate Key
- The candidate key can having only one attribute or composite as well.
For example :
Primary Key
Stud_id
Name
PRN
Aadhar
Number
Age
1
Prashant
121
4****9
19
2
Ritesh
122
4****3
18
3
Vivek
123
4****5
21
4
Prashant
124
4****6
25
5
Rahul
125
4****7
23
Keys : Super Key
Super Key :
- It is a set of an attribute that can uniquely identify a tuple.
- In Super key there is no restriction on number of attributes, it may consist of any number of attributes
For example :
Super Key
Stud_id
Name
PRN
Aadhar
Number
Age
1
Prashant
121
4****9
19
2
Ritesh
122
4****3
18
3
Vivek
123
4****5
21
4
Prashant
124
4****6
25
5
Rahul
125
4****7
23
Keys : Foreign Key
Foreign key :
- To point to the primary key of another table foreign key columns are used.
- Foreign Key is used to establish relationships between two tables
Keys : Foreign Key
Stud_Id
Name
Div
Dept_Id
1
ABC
B
1
2
XYZ
B
2
3
LMN
B
3
Primary
Key
Primary Key
Foreign Key
Relationship
Dept_Id
Dept_Name
College_Name
1
AI and DS
VIIT
2
Computer
VIIT
3
IT
VIIT
Keys : Alternate Key
Alternate key :
Those candidate keys which are not the Primary key are Alternate keys.
Design Process
Design process consist of Collection of multiple tasks including designing, development,
implementation, and maintenance of data management system.
It provide the technical drawing of how the data is going to be stored in a system.
Design process provides clear idea about the behavior of any application
It also the reduces the processing time of an application
Design Process
Life Cycle
- Requirement Analysis :
- Planning : based on basic requirements which defines boundaries and scope of database
- Database Designing :
- Splitting into various models
Physical Model
Logical Model : It is paper work, actual implementation of database not required
- Implementation
- behavior of the application based on the requirements
- Data conversion and loading
- Testing
Design Process
Database design must able to do below mentioned things :
- Eliminating redundant data
- Accuracy of Data
- Proper access to the data
Extended Entity-Relationship (EE-R)
- It is extensions to the original ER model.
- EE-R includes below mentioned concepts to create EE-R diagrams −
Subclasses and Super classes.
Specialization and Generalization.
Category or union type.
Aggregation.
Extended Entity-Relationship (EE-R)
- Subclasses and Super class
Super class is kind of entity which can be divided into further subtype.
Sub classes are the group of entities consist of some unique attributes.
Sub class inherits the properties and attributes from super class.
For example − consider Department super class.
Super class Department has sub groups: AInDS, Computer and IT.
Extended Entity-Relationship (EE-R)
Generalization
- By identifying common attributes from a set of entities, a generalized entity can be created.
- Generalization Is a bottom-up approach.
- Two or more entities can be generalized to a higher level entity, if these entities have some
attributes in common.
Extended Entity-Relationship (EE-R)
Generalization
Extended Entity-Relationship (EE-R)
Specialization
- In specialization process an entity is divided into sub-entities based on their features.
- It is a top - down approach.
- In this process higher level entity can be specialized into two or more entities.
Extended Entity-Relationship (EE-R)
Specialization
Extended Entity-Relationship (EE-R)
- Category or Union
- This type consist of relationship of one super or sub class with more than one super class.
Extended Entity-Relationship (EE-R)
Category or Union
Extended Entity-Relationship (EE-R)
Aggregation
- In the case of E-R diagram it is not possible to represent relationship between as entity and a
relationship.
- With the help of aggregation relationship with its corresponding entities is aggregated into a higher
level entity.
Extended Entity-Relationship (EE-R)
Aggregation
References
Abraham Silberschatz, Henry Korth, S.Sudarshan," Database System concepts".
References
https://www.conceptatech.com
https://www.javatpoint.com
https://www.tutorialspoint.com
https://www.guru99.com
https://www.gatevidyalay.com
https://www.geeksforgeeks.org