3. R D B M S
Relational Data base Management System
4. Data
• Data is defined as facts or figures, or information that's stored
in or used by a computer.
• Word 'Data' is originated from the word 'datum' that means
'single piece of information‘.
Example: 1 , A , B.Com , B.A. , @ , etc.
5. Database
• A database is an organized collection of data, so that it can be
easily accessed and managed.
• They support electronic storage and manipulation of data.
Databases make data management easy.
Example: An online telephone directory uses a database to store
data of people, phone numbers, other contact details.
Example of Database: MySQL, Oracle, etc.
6. Database Management
Database Management, allows a person to organize, store and
retrieve data from a computer.
Managing a database involves designing and implementation of
stored data.
7. Database Management System
• Database management system is a software which is used to
manage the database. For example: MySQL, Oracle, etc are a
very popular commercial database which is used in different
applications.
• DBMS provides an interface to perform various operations like
database creation, storing data in it, updating data, creating a
table in the database and a lot more.
• It provides protection and security to the database. In the
case of multiple users, it also maintains data consistency.
8. DBMS allows users the following tasks:
• Data Definition: It is used for creation, modification, and
removal of definition that defines the organization of data in
the database.
• Data Updation: It is used for the insertion, modification, and
deletion of the actual data in the database.
9. • Data Retrieval: It is used to retrieve the data from the
database which can be used by applications for various
purposes.
• User Administration: It is used for registering and monitoring
users, maintain data integrity, enforcing data security,
monitoring performance and recovering information
corrupted by unexpected failure.
10. Advantages of DBMS
• Controls database redundancy: It can control data
redundancy because it stores all the data in one single
database file and that recorded data is placed in the database.
• Data sharing: In DBMS, the authorized users of an
organization can share the data among multiple users.
11. • Easily Maintenance: It can be easily maintainable due to the
centralized nature of the database system.
• Reduce time: It reduces development time and maintenance
need.
• Backup: It provides backup and recovery subsystems which
create automatic backup of data from hardware
and software failures and restores the data if required.
• Multiple user interface: It provides different types of user
interfaces like graphical user interfaces, application program
interfaces
12. Disadvantages of DBMS
• Cost of Hardware and Software: It requires a high speed of
data processor and large memory size to run DBMS software.
• Size: It occupies a large space of disks and large memory to
run them efficiently.
13. • Complexity: Database system creates additional complexity
and requirements.
• Higher impact of failure: Failure is highly impacted the
database because in most of the organization, all the data
stored in a single database and if the database is damaged
due to electric failure or database corruption then the data
may be lost forever.
14. RDBMS
• RDBMS stands for Relational Database Management Systems.
• All modern database management systems like SQL, ORACLE,
My-SQL and Microsoft Access are based on RDBMS.
• It is called Relational Data Base Management System (RDBMS)
because it is based on relational model introduced by E.F.
Codd.
16. What is File Oriented System?
A File Management system is a DBMS that allows acces to
single files or tables at a time. In a File System, data is directly
stored in set of files. It contains flat files that have no relation
to other files (when only one table is stored in single file, then
this file is known as flat file).
17. File system is basically a way of arranging the files in a
storage medium like hard disk. File system organizes
the files and helps in retrieval of files when they are
required. File systems consists of different files which
are grouped into directories. The directories further
contain other folders and files. File system performs
basic operations like management, file naming, giving
access rules etc.
22. DBMS Architecture
• The DBMS design depends upon its architecture. The basic
client/server architecture is used to deal with a large number
of PCs, web servers, database servers and other components
that are connected with networks.
• The client/server architecture consists of many PCs(personal
computers) and a workstation which are connected via the
network.
• DBMS architecture depends upon how users are connected to
the database to get their request done.
23. Types of DBMS Architecture
Database architecture can be seen as a single tier or multi-tier.
But logically, database architecture is of two types like: 2-tier
architecture and 3-tier architecture.
24. 1-Tier Architecture
• In this architecture, the database is directly available to the
user. It means the user can directly sit on the DBMS and uses
it.
• Any changes done here will directly be done on the database
itself. It doesn't provide a handy tool for end users.
• The 1-Tier architecture is used for development of the local
application, where programmers can directly communicate
with the database for the quick response.
25. 2-Tier Architecture
• The 2-Tier architecture is same as basic client-server. In the
two-tier architecture, applications on the client end can
directly communicate with the database at the server side.
• The user interfaces and application programs are run on the
client-side.
• The server side is responsible to provide the functionalities
like: query processing and transaction management.
• To communicate with the DBMS, client-side application
establishes a connection with the server side.
27. 3-Tier Architecture
• The 3-Tier architecture contains another layer between the
client and server. In this architecture, client can't directly
communicate with the server.
• The application on the client-end interacts with an application
server which further communicates with the database system.
• End user has no idea about the existence of the database
beyond the application server. The database also has no idea
about any other user beyond the application.
• The 3-Tier architecture is used in case of large web
application.
29. Three Level/Schema/Tier Architecture
• The three schema architecture is also called ANSI/SPARC
architecture or three-level architecture.
• This framework is used to describe the structure of a specific
database system.
• The three schema architecture is also used to separate the
user applications and physical database.
30. • The three schema architecture contains three-levels. It breaks
the database down into three different categories.
Definition of schema:
Design of a database is called the schema.
The three-level architecture is as follows:
33. In the above diagram:
• It shows the DBMS architecture.
• Mapping is used to transform the request and response
between various database levels of architecture.
• Mapping is not good for small DBMS because it takes more
time.
• In External / Conceptual mapping, it is necessary to transform
the request from external level to conceptual schema.
• In Conceptual / Internal mapping, DBMS transform the
request from the conceptual to internal level.
34. 1. Internal Level
• The internal level has an internal schema which describes the
physical storage structure of the database.
• The internal schema is also known as a physical schema.
• It uses the physical data model. It is used to define that how
the data will be stored in a block.
• The physical level is used to describe complex low-level data
structures in detail.
35. 2. Conceptual Level
• The conceptual schema describes the design of a
database at the conceptual level. Conceptual level is also
known as logical level.
• The conceptual schema describes the structure of the
whole database.
36. • The conceptual level describes what data are to be stored in
the database and also describes what relationship exists
among those data.
• In the conceptual level, internal details such as an
implementation of the data structure are hidden.
• Programmers and database administrators work at this level.
37. 3. External Level
• At the external level, a database contains several schemas
that sometimes called as subschema. The subschema is used
to describe the different view of the database.
• An external schema is also known as view schema.
• Each view schema describes the database part that a
particular user group is interested and hides the remaining
database from that user group.
• The view schema describes the end user interaction with
database systems.
38. DBMS Schema
• Design of a database is called the schema.
• Schema is of three types: Physical schema, logical schema and
view schema.
• The design of a database at physical level is called physical
schema, how the data stored in blocks of storage is described
at this level.
39. • Design of database at logical level is called logical schema,
programmers and database administrators work at this level,
at this level data can be described as certain types of data
records gets stored in data structures, however the internal
details such as implementation of data structure is hidden at
this level (available at physical level).
• Design of database at view level is called view schema. This
generally describes end user interaction with database
systems.
40. • For example: In the following diagram, we have a schema that
shows the relationship between three tables: Course, Student
and Section. The diagram only shows the design of the
database, it doesn’t show the data present in those tables.
Schema is only a structural view(design) of a database as
shown in the diagram below.
42. Evolution of Database Technology
The evolution of database starts from early 1960 when
databases only used to retrieve the information. The evolution
of database are as follows:
•File Based Database
Earlier users stored data into flat files. Punch card technology
was used by the end user to store the data. At that time the
sequential and random method was used to access the data
from flat files. It was best for the small database where a
relationship was not required.
43. File-oriented system is a method, in which the operating
system keeps the records of data in different files. Each and
every operating system having a specific file system to store
data. Windows operating system has following file systems.
1. FAT 32 (File Allocation Table 32) :
It was introduced in 1977, used to store the data into a
computer in a different manner. Inbuilt security was not there
in this file system. File storage size was limited. It was the
oldest file system so it can be used by a mostly operating
system. It supports maximum file size 4GB.
44. 2. NTFS (New File System) :
It was introduced in 1993, used to store the large data into a
computer. It provides inbuilt security, compression, and
recoverability features. The speed of data storage and
retrieval is high as compared to FAT 32. It supports maximum
file size 16 TB.
45. • Hierarchical Model
• This database model organizes data into a tree-like-structure, with a
single root, to which all the other data is linked. The hierarchy starts
from the Root data, and expands like a tree, adding child nodes to
the parent nodes.
• In this model, a child node will only have a single parent node.
• In hierarchical model, data is organized into tree-like structure with
one one-to-many relationship between two different types of data,
for example, one department can have many courses, many
professors and of-course many students.
47. • Network Model
• This is an extension of the Hierarchical model. In this model
data is organized more like a graph, and are allowed to have
more than one parent node.
• In this database model data is more related as more
relationships are established in this database model. Also, as
the data is more related, hence accessing the data is also
easier and fast. This database model was used to map many-
to-many data relationships.
• This was the most widely used database model, before
Relational Model was introduced.
49. • Entity-relationship Model
• In this database model, relationships are created by dividing object
of interest into entity and its characteristics into attributes.
• Different entities are related using relationships.
• E-R Models are defined to represent the relationships into pictorial
form to make it easier for different users to understand.
• This model is good to design a database, which can then be turned
into tables in relational model (explained below).
50. • Let's take an example, If we have to design a School Database,
then Student will be an entity with attributes name, age,
address etc. As Address is generally complex, it can be
another entity with attributes street name, pin code, city etc,
and there will be a relationship between them.
51. • Relational Model
• In this model, data is organized in two-dimensional tables and the
relationship is maintained by storing a common field.
• This model was introduced by E.F Codd in 1970, and since then it
has been the most widely used database model, in fact, we can say
the only database model used around the world.
• The basic structure of data in the relational model is tables. All the
information related to a particular type is stored in rows of that
table.
• Hence, tables are also known as relations in relational model.
53. Object-Oriented Databases
Object-oriented databases (OODB) are databases that
represent data in the form of objects and classes. In object-
oriented terminology, an object is a real-world entity, and
a class is a collection of objects. Object-oriented databases
follow the fundamental principles of object-oriented
programming (OOP). The combination of relational model
features with object-oriented principles results in an object-
oriented database model.
55. Object-Relational Database Management
System
An object-relational database (ORD), or object-relational
database management system (ORDBMS), is a database
management system (DBMS) similar to a relational database,
but with an object-oriented database model: objects, classes
and inheritance are directly supported in database
schemas and in the query language.
56. Data Mining?
• The process of extracting information to identify patterns,
trends, and useful data that would allow the business to take
the data-driven decision from huge sets of data is called Data
Mining.
• In other words, we can say that Data Mining is the process of
investigating hidden patterns of information to various
perspectives for categorization into useful data, which is
collected and assembled in particular areas such as data
warehouses, efficient analysis, data mining algorithm, helping
decision making and other data requirement to eventually
cost-cutting and generating revenue.
57. What is Data Warehousing
• A Data Warehousing (DW) is process for collecting and
managing data from varied sources to provide meaningful
business insights. A Data warehouse is typically used to
connect and analyze business data from heterogeneous
sources .
• It is electronic storage of a large amount of information by a
business which is designed for query and analysis instead of
transaction processing. It is a process of transforming data
into information and making it available to users in a timely
manner to make a difference.
58. Web database
A Web database is a database application designed to be
managed and accessed through the Internet. Website
operators can manage this collection of data and present
analytical results based on the data in the Web database
application.
59. XML Database
• Extensible Markup Language is a markup language that
defines a set of rules for encoding documents in a format that
is both human-readable and machine-readable.
• XML database is a data persistence software system used for
storing the huge amount of information in XML format. It
provides a secure place to store XML documents.
60. Evolution of database technology:
1950s : Computers used for Census.
1958s : Data was maintained in flat files.
1960s : Hierarchical database, Network database, IMS.
1970s : E-R model, Relational model
1980s : RDBMS, Advanced data models.
1990s : Data mining, Data warehousing, Web databases.
2000s : Web based systems: XML databases.
2010s : Sensor DB systems, DBs on embedded systems
61. Client Server Platform
• In Client server architecture, computers are connected
through a Central Server.
• Each computer on the network is either a client or a server.
• Servers are most powerful and they can manage the clients
from the central location.
• Clients request and receive signals from a centralized server.
62. Client Server Platform
• Servers wait for requests to arrive from clients and then
respond to them.
• The server can also manage the files on the file servers or can
control the network traffic.
• Clients are less powerful than a server.
• All the clients and server are connected to a network device.
64. Database System in the Organization
Operational Data
• Basically the data is raw facts.
• These raw facts, available in any enterprise must be identified
and collected.
• The identified data of an enterprise are called as operational
data.
65. Operational Data
• The recording of such operational data is required to produce
the information.
• These data may be the facts of objects, persons or things of
an enterprise.
• The identification of operational data in any enterprise is
beginning step of the database management system.
• All the activities of the DBMS are initiated from the collection
of operational data itself.
66. Introduction to Database
• Database is a storage that holds large amount of data.
• The stored data is used to produce information as and when
required.
• Generally speaking the database is nothing but a storage place of
data which is of interest to the enterprise.
• The database is physically present on the secondary storage or disk.
• So, the data stored in the database remains permanent so that it
can be used later.
• The quantity of the data stored in database depends on the size of
the enterprise.
67. Introduction to Database
• The functionalities related to the database are :
– Creation of the database
– Insertion of data into the database
– Updating data in the database
– Effective retrieval of data from the database
– Securing of data stored in the database
– Deletion of data from the database
• These functionalities of the database can only be implemented
through proper programs. The set of programs that manages the
database is called as DBMS, the Database Management System.
68. Types of Database
Common Operational Database
• Operational database stores complete data need to support
the entire business enterprise .
• They are also called Subject area database(SADB), transaction
database and manufacturing database.
• Example: Customer database, Inventory database, Finance
database, etc.
69. Types of Database
Database Sharing
• Shared database is used to distribute the organization data to
the external and internal environment using network.
• The distributed database is kept on central server on the
global network (WWW), on companies intranet or extranet.
70. • Intranet :
Intranet is owned by a single organization and is a tool for
sharing information throughout the organization. It is the type
of Internet that is used privately. Since, intranet is a private
network so no one can use the intranet whose have not valid
username and password. In intranet, there are a limited
number of connected devices as compared to internet.
Intranet is highly secure and has a small number of visitors. It
is used in order to get employee information, telephone
directory etc.
71. • Extranet :
Extranet is owned by either a single or a many organization. It
is managed on a contractual basis between organizations and
is a tool for sharing information between the internal
members and external members. Like intranet, it is also a
private network so only those who have a valid username and
password can use the extranet. Extranet is used to check
status, access data, send mail, place order etc.
72. Types of Database
Personal Database
• Personal database is used to keep the data of particular
employee.
• Only the authorized user is able to access their own database,
it is called home directory of a user where a user can kept
their official and personal file.
• In a large organization, every user has their own database.
73. Types of Database
External Database
• External database is available for commercial purpose by the
organizations and end users.
• End users are paid for these databases.
• These databases can contain newspapers, magazines and journals,
etc.
• External database is used as online paid database.
• Example: e-journals, e-magazines, etc.
74. Data Ware House
• Data warehouse is a data storage area of an enterprise.
• The data warehouse is designed for reporting and analysis
purpose.
• It is a central source of data that has been structured and
analyses, so they can be used by managers for decision
making capability.
• The tool which is used to extract the data and information
from the data ware house is called Data. Mining.
75. Data Abstraction
• When the data is retrieved effectively and efficiently then it is
in the utilizable form.
• When such efficient retrieval system is required the data
structure design becomes more complex.
• Most of the users of DBMS normally do not have enough
knowledge of computer systems.
• Training them in all aspects is not possible.
76. Data Abstraction
• They can only be trained to use the FORMS or DATA ENTRY
SCREENS to work with.
• So, it is the duty of the developers to provide user friendly
environment.
• Here comes the need of hiding the details of data.
• The database management system developers hide the
complexity of data in the system.
• It is done through several levels of abstraction to simplify user
interaction with the system.
77. Levels of Data Abstraction
• The details of the data are hidden at the three levels namely
Physical Level, Logical Level and View Level.
• The View Level is at the highest level of data abstraction
whereas the Physical Level is the lowest level. In between
comes the Logical Level.
78. Strategic Database planning
• Database is used to store, manipulate and retrieve data in
every organization.
• It is used by either individually or department wise.
• Database planning is strategic corporate effort to determine
the necessity of information for the organization from the
current time to the future time.
• Organization's managers should know the futuristic demand
of databases and their size.
79. Management Control
• Every organization databases need control and protection and
DBA is responsible for this.
• Management control is the mechanism by which the users
and managers assure that the data and information are
gathered and efficiently used to achieve desired goal of an
organization.
• Management control is also used to protect the database
system and the data within.
• Different types of management controls are as follows:
80. Management Control
• Integrity control Mechanism
• This type of control is used by the organization to help
prevent the wrong data being entered into a system.
• It prevents data from unauthorized access and malicious
programs.
• The main purpose of integrity control is to enter the correct
data into a system and maintain the record of each and every
transaction occurs in the organization.
81. Management Control
• Access Control Mechanism
• In this, the system prevents to add, modify and delete the record
from the database system.
• Security Control Mechanism
• In this, organization protect the data from the outside threats using
security. Each and every database has assigned the controls to
access these contents using authentication or authorization.
82. Management Control
• Security Control Mechanism
• In this organization protect the data from the outside threats
using security.
• Each and every database has assigned the controls to access
these contents using authentication or authorization.
83. Risks and Cost of Database
Planning, creating and implement the database in an
organization always involves a time, risk, and cost. Every
organization invests in a database when they need it.
Following factors are categorized in cost and risk.
• Specialized DBA
• The technology is growing rapidly and every time when the
new database is going to design, it requires a DBA and their
team.
84. Risks and Cost of Database
• Installation Cost
• Each and every time new hardware and software is required
for creating a new database, it involves huge cost and
investment.
• The DBMS must be efficient and will generally need more
space and memory.
• These overhead costs may not always bring benefits.
85. Risks and Cost of Database
• Design Risk
• Design problem is there at the time of database creation. The
design problem involves:
1. Not estimated the proper budget (over budget)
2. Lack of communication between user and developer
3. Redesign the database always involves more cost and time.
4. Not fulfill the user's requirements.
5. Complex design, not understand by end users
86. Risks and Cost of Database
• Training and Developing
• When the new database is designed, at that time organization
needs a specialized person to operate it, or required a training
and development programs for their existing employees, so
that the organization utilize the database resources.
87. Risks and Cost of Database
• Backup cost rate
• It involves backup and recovery of the database.
• In this organization creates a secondary database for backup
purpose and prevents from fault tolerance and it involves a
higher cost
88. Risks and Cost of Database
• Security risk
• Risk is always involved for accessing the data from a database.
• Risks are:
■ Unauthorized access to a database :-
Unauthorized user can easily theft the data from the database if
proper security mechanism is not there.
89. Risks and Cost of Database
• Security risk
■ Damaging the data: -
If proper security and authentication is not there, then someone
can- easily damage the important data from the database. Each and
every database should have security and privacy features like:
(i) Authentication
(ii) Complex Password (at least one capital letter, one symbol, and
one number)
(iii) Antivirus
(iv) Firewall
(v) Database failure
90. Risks and Cost of Database
• Security risk
■ System Failure :-
• If the users are working and main computer system goes down, at
that time all the users cannot access the database until the system
is functional again.
• Sometime this may require a long wait.
• So it is important that all the softwares required for database
maintenance are carefully handled.
91. Logical and physical data representation
• Data representation is a methodology to describe the
structure of database.
• The data structure explains the data type and relationship
that hold the data.
• A data which enters into the computer can be of any type like
number, text, and multimedia.
92. Logical and physical data representation
Logical Data representation
• Logical data is used to represent the need for business rather than
design the database.
• In this data is representing as an attribute, entity, and relationship.
• An entity defines the real-time objects such as details of products
describe in a database.
• An attribute represents the property of the entity such as product's
name and their prize.
• In relationship 2 or more entities are associated with each other
and defines the relationships among them.
93. Logical and physical data representation
Physical Data representation
• The concept of physical data is that how data is stored on the
computer.
• Data can be represented in secondary storage like hard disk,
CD, DVD, and Removable device.
• The data is representing in a proper context.
