DATABASE Lecture 1 and 2.pptx

DATABASE
By: Rubab
Instructor Computer Science
IBA Sukkur- Institute of Emerging
Technologies

What is a Data?
Data: A collection of raw facts and figures.
Raw material that can be processed by any computing
machine.
A collection of facts from which conclusions may be drawn.
Data can be represented in the form of numbers and words
which can be stored in computer’s language.

What is Information
Information: Systematic and meaningful form
of data.
Knowledge acquired through study or
experience.
Information helps human beings in their
decision making.

What is Database
Database: A repository of logically related and similar
data. •
An organized collection of related information so that
it can easily be accessed, managed and updated.
E.g Dictionary, Airline Database, Student Database,
Library, Railways Timetable YouTube

Entity
•Person
•Place
•Object
An entity is an
object that
exists, and
Data can be
stored about it.
An entity can
be

Attribute
An attribute is characteristics or properties that describes an entity
Example: A Person is an Entity, and it has Attributes like :
Name
Age
Height

Example we have Entity Chair
Legs
Material
Color

Column (field, attribute):
A column is the smallest unit of storage in a database.
A column stores an Attribute about an object.
Every column has a name and a data type.
Columns run vertically. They are grouped to form a Row.

Row (Record, Tuple)
A row is a collection of column values
Row is composed of the same set of columns
A row represents the information of a real-world entity based
on its attributes
Rows run horizontally.

What is a Table?
A table (relation, class, file) is responsible for storing data in the database.
Database tables consist of rows and columns.
Row 1
Row 2
Row 3
Row 4
Row 5
Column 1 Column 2 Column 3

Types of Databases
1. Hierarchical databases
2. Centralized databases
3. Distributed databases
4. Flat File Database
6. Relational databases
7. Object oriented
databases
8. NoSQL databases
9. Cloud databases
10. Network Databases
11. Enterprise Database
12. Personal Database
13. Operational Database

Centralized
Database
It is the type of database that stores data at a centralized
database system. It allows users to access the stored data
from different locations through several applications. These
applications contain the authentication process to let users
access data securely. An example of a Centralized database
can be Central Library that carries a central database of each
library in a college/university.

Distributed
Databases
Unlike a centralized database system, in distributed
systems, data is distributed among different database
systems of an organization. These database systems are
connected via communication links. Such links help the
end-users to access the data easily. Examples of the
Distributed database are Apache Cassandra, HBase, Ignite,
etc.

Distributed
Databases
There are
two types
of
Distributed
Databases
Homogeneous DDB: Those
database systems which execute
on the same operating system
and use the same application
process and carry the same
hardware devices.
Heterogeneous DDB: Those
database systems which execute
on different operating systems
under different application
procedures and carries different
hardware devices.

Relational Database
This database is based on the relational data model, which stores data in
the form of rows(tuple) and columns(attributes), and together forms a
table(relation). A relational database uses SQL for storing, manipulating,
as well as maintaining the data. E.F. Codd invented the database in 1970.
Each table in the database carries a key that makes the data unique from
others. Examples of Relational databases are MySQL, Microsoft SQL
Server, Oracle, etc.

ACID Properties of Relational Database
Atomicity: This ensures the data operation will complete either with success or with failure. It follows the
'all or nothing' strategy. For example, a transaction will either be committed or will abort.
Consistency: If we perform any operation over the data, its value before and after the operation should
be preserved. For example, the account balance before and after the transaction should be correct, i.e.,
it should remain conserved.
Isolation: There can be concurrent users for accessing data at the same time from the database. Thus,
isolation between the data should remain isolated. For example, when multiple transactions occur at the
same time, one transaction effects should not be visible to the other transactions in the database.
Durability: It ensures that once it completes the operation and commits the data, data changes should
remain permanent.

NoSQL Database
Non-SQL/Not Only SQL is a type of database that is used for storing a
wide range of data sets. It is not a relational database as it stores data not
only in tabular form but in several different ways. It came into existence
when the demand for building modern applications increased. Thus,
NoSQL presented a wide variety of database technologies in response to
the demands

Types of NoSQL DB
1. Key-value storage: It is the simplest type of database storage where it stores every
single item as a key (or attribute name) holding its value, together.
2. Document-oriented Database: A type of database used to store data as JSON-like
document. It helps developers in storing data by using the same document-model
format as used in the application code.
3. Graph Databases: It is used for storing vast amounts of data in a graph-like
structure. Most commonly, social networking websites use the graph database.
4. Wide-column stores: It is like the data represented in relational databases. Here,
data is stored in large columns together, instead of storing in rows.

Cloud Database
A type of database where data is stored in a virtual environment and
executes over the cloud computing platform. It provides users with
various cloud computing services (SaaS, PaaS, IaaS, etc.) for accessing
the database. There are numerous cloud platforms, but the best options
are:
Amazon Web Services(AWS), Microsoft Azure and Google cloud.

Object Oriented Database
The type of database that uses the object-based data model approach for
storing data in the database system. The data is represented and stored
as objects which are like the objects used in the object-oriented
programming language.

Hierarchical Databases
It is the type of database that stores data in the form of parent-children
relationship nodes. Here, it organizes data in a tree-like structure.
Data get stored in the form of records that are connected via links. Each
child record in the tree will contain only one parent. On the other hand,
each parent record can have multiple child records.

Network Database
It is the database that typically follows the network data model. Here, the
representation of data is in the form of nodes connected via links between
them. Unlike the hierarchical database, it allows each record to have
multiple children and parent nodes to form a generalized graph structure.

Personal Databases
Collecting and storing data on the user's system defines a Personal
Database. This database is basically designed for a single user.

Operational Database
The type of database which creates and updates the database in real-
time. It is basically designed for executing and handling the daily data
operations in several businesses.
For example, An organization uses operational databases for managing
per day transactions.

Enterprise Database
Large organizations or enterprises use this database for managing a
massive amount of data. It helps organizations to increase and improve
their efficiency. Such a database allows simultaneous access to users.

Flat File Database
A flat file/ flat form database is a system that stores data within a single table. It
is known as a flatform database due to it only containing a two-dimensional
structure (data fields and records). The database contains data fields which is
the name of each piece of data being collected example address meaning that
there will be a list of multiple addresses contained within that column. The
database also contains records which is the information of each individual for
example when you want to find out information about a particular person you
could search their name and the database will show all the data collected within
each data field for that certain individual. Example MS Excel

DBMS
Database Management System (DBMS) is a software for storing and retrieving
users’ data while considering appropriate security measures. It consists of a
group of programs which manipulate the database. The DBMS accepts the
request for data from an application and instructs the operating system to
provide the specific data. In large systems, a DBMS helps users and other third-
party software to store and retrieve data.
DBMS allows users to create their own databases as per their requirement. The
term “DBMS” includes the user of the database and other application programs.
It provides an interface between the data and the software application.

RDBMS
RDBMS stands for Relational Database Management System
An RDBMS is a type of database management system (DBMS) that
stores data in a row-based table structure which connects related data
elements. An RDBMS includes functions that maintain the security,
accuracy, integrity and consistency of the data. This is different than the
file storage used in a DBMS.

RDBMS
Database application
Relational Database
Management System
Database
User 1 User 2 User n

DATABASE Lecture 1 and 2.pptx

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DATABASE Lecture 1 and 2.pptx