This document provides an overview of different database models and concepts. It discusses flat file/sequential, hierarchical, network, relational, entity-relationship, and object-oriented database models. For each model, it describes the basic concepts, examples, advantages and disadvantages. Key concepts covered include entities, attributes, relationships, normalization, data redundancy, and database management systems.
PHP provides access to a great number of different database systems, many of which are relational in nature and can be interrogated using Structured Query Language (SQL).
Basics, Components, Design and Development of Web Application and Websites. Especially made for seminars and guest sessions for newbies in Web Development field.
STAENZ Academy
https://staenz.com/academy
PHP provides access to a great number of different database systems, many of which are relational in nature and can be interrogated using Structured Query Language (SQL).
Basics, Components, Design and Development of Web Application and Websites. Especially made for seminars and guest sessions for newbies in Web Development field.
STAENZ Academy
https://staenz.com/academy
Operating system 32 logical versus physical addressVaibhav Khanna
How to utilize memory optimally by manipulating objects in the memory is referred to as memory management.
Program must be brought (from disk) into memory and placed within a process for it to be run
Main memory and registers are only storage CPU can access directly
Memory unit only sees a stream of addresses + read requests, or address + data and write requests
Register access in one CPU clock (or less)
Main memory can take many cycles, causing a stall
Cache sits between main memory and CPU registers
Protection of memory required to ensure correct operation
DDBMS, characteristics, Centralized vs. Distributed Database, Homogeneous DDBMS, Heterogeneous DDBMS, Advantages, Disadvantages, What is parallel database, Data fragmentation, Replication, Distribution Transaction
To understand an OS, let’s first look at its components and then how they’re composed or organized.
We’ll come back and look at each of these in detail as the course progresses.
Realize that it’s never as simple as it looks. These basic concepts exist in some form in all systems, however each system implements them in a slightly different way.
Also, the divisions between components may not be as clean in the real world as in the model
Operating system 32 logical versus physical addressVaibhav Khanna
How to utilize memory optimally by manipulating objects in the memory is referred to as memory management.
Program must be brought (from disk) into memory and placed within a process for it to be run
Main memory and registers are only storage CPU can access directly
Memory unit only sees a stream of addresses + read requests, or address + data and write requests
Register access in one CPU clock (or less)
Main memory can take many cycles, causing a stall
Cache sits between main memory and CPU registers
Protection of memory required to ensure correct operation
DDBMS, characteristics, Centralized vs. Distributed Database, Homogeneous DDBMS, Heterogeneous DDBMS, Advantages, Disadvantages, What is parallel database, Data fragmentation, Replication, Distribution Transaction
To understand an OS, let’s first look at its components and then how they’re composed or organized.
We’ll come back and look at each of these in detail as the course progresses.
Realize that it’s never as simple as it looks. These basic concepts exist in some form in all systems, however each system implements them in a slightly different way.
Also, the divisions between components may not be as clean in the real world as in the model
database management system - overview of entire dbmsvikramkagitapu
What is DBMS? Database Management Systems (DBMS) are software systems used to store, retrieve, and run queries on data. A DBMS serves as an interface between an end-user and a database, allowing users to create, read, update, and delete data in the databas
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
2. Database :-
A Database is a structure that can store information
about multiple types of entities ,and the relationships
among the entities .
Entity :-
An entity is a person , place, object or idea for which
you want to store and process data.
Attribute:-
An Attribute is a characteristic or property of an entity.
The term used in this text exactly as it is used.
Data Base Management System :-
A DBMS is a program or a collection
of programs , though which users interact with a database . The actual
manipulation of the underlying in handled by the DBMS .
2
3. Database application:-
An application program (or set of related
programs)that is used to perform a series of database activities (Create, read,
update and delete) on behalf of database users. Each database application
performs some combination of the following basic operation
1)Create :- Add new data to the database.
2)Read :- Read current database data (often presented in a useful format on a
computer screen or on a printed report).
3)Update :- Update or modify current data.
4)Delete :- Delete current data from the database.
3
4. DBMS Advantages
DBMS has many advantages such as:
Reduction in data Redundancy :-
It means that DBMS helps in removing duplicate
data from the database. It will notice that Redundancy leads to several problems:
i) Duplication of Efforts .
ii) Save the storage space /memory where data is saved.
Provides Security :-
Restrict users to access all the information of the database by
providing passwords and rights .there are also various coding techniques to maintain the security of
important and crucial information from unauthorized users and accidents.
4
5. DBMS Advantages
Data can be shared among various users:-
In a database system , data can be
easily shared by different users .For example ,student data can shared by teacher
department subject wise ,Fee department ,library etc.
Data Integrity :-
since a large number of users can access database together at the same
time . So, to maintain the same data/information correct every time and at every
place during any operation is called data integrity.
Maintenance of data integrity :-
data Integration can be understood by the fact
that data contained in the database should be accurate and consistent.
5
6. Types of DBMS Models
These categories are made on the basis of the ways in which data are stored in
the database :
1)Flat file or sequential .
2)Hierarchical
3)Network
4)Relational
5)Entity–relationship model
6)Object database
6
7. Sequential or Flat File
Flat File:-
A Flat File can be defined as a text file in which you can organize the data in
your own format and it is not linked with any other file .In this the data is processed in the
way the data is stored.
Example:-MS Spread Sheet.
Item name Price Quantity Store Name Date of sale
Bread 15 5 saravana 30-08-2014
Butter 46 6 saravana 30-08-2014
Biscuits 56 8 saravana 01-09-2014
7
8. Sequential or Flat File
Advantages of Flat File System:-
1) It is simple and easy to implement.
2) It can be used for small database
3) It is used where no links between data or files are required.
Disadvantage of File System :-
1)Duplication of data Entries.
2)Since the access mode is sequential or in a single order, the system gets
slower for large database.
3)The file is hard to recover if it is corrupted or system crashes .
8
9. Hierarchical Database Model
• In this kind of database, data are stored in the form of a hierarchy .Hierarchy
database is like a tree structure which has one root and many branches .It uses the
concept of parent child relation ship .in this type of database a single file may have
many relationship.
this system is very advance compare to sequential system(a flat file).
9
11. Hierarchical Database Model
Advantages of Hierarchical databases :-
it is having following advantage
1) Hierarchical model is simple to construct.
2)This type of database is generally used in daily life organizations
where data is organized in hierarchically organized domains,
component assemblies in manufacturing ,personnel organization in
companies.
3)Accessing of data is faster in hierarchical database compared to
sequential database.
11
12. Hierarchical Database Model
Disadvantages of Hierarchical Database :-
1) Complex implementation
2)Difficult to manage
3)Lacks structural independence
4)Complex applications programming and use
5)Implementation limitations
6)Lack of standards
12
13. Network database model
• In this model, a parent can have many children and a child can also
have many parent records. These records are physically linked
through linked lists.
network model was developed in mid 1960s as part of work of
CODASYL(Conference on Data Systems Languages) which
proposed programming language COBOL(1966) and then network
model(1971).
13
15. Network database model
Advantages of network Model:-
1)It eliminates unnecessary duplication of data with associated errors and
costs.
2)It uses concept of a data definition language ,data manipulation language .
3)It uses concept of m:n linkages or relationships, which mean that an owner
record can have many members records. Similarly a member record can have
several owners .but a hierarchical model allows only 1:n
Disadvantages of network Model :-
1)System complexity
2)Lack of structural independence
15
16. Relational data model :-
In this model of DBMS ,data is stored in two- dimensional table (rows, and columns ),this is a
model relation between two tables exists with something in common or some data which these
two tables share. Each column of a table is referred ta as an attribute and the values which it may
contain is called domain of values.
In this model was proposed by IBM researcher E.F.Codd in 1970. it is more of a concept than a
data structure varies substantially from one RDBMS to another .Relational database model use
relational concept of mathematics in a table .
You can understand Relational Model where
Each row is a record or tuple.
Each column is an attribute.
Primary Key:-
the Primary Key of a table uniquely identifies the record .
Foreign Key :-
16
The Foreign key is the key of a table which is used for referencing the other table .
17. Relational data model :-
• Example :1 Student table and its primary Key
ID No
(Primary Key)
Student Name Class Department
S34877 Raja Sekhar MLIS Library and Information Science
S34878 Avani MSc Computer Science
S34879 Kadiresan MLIS Library and information science
S34880 Amees MLIS Library and information science
S34881 Gopi MA English
S34882 Shyndeep MLIS Library and information science
S34883 Rajesh MBA Business Management
17
18. Relational data model :-
• Example :- Library Table
Book No
(Primary Key)
ID No
(Foreign Key)
Title Issued Date
12567 S34877 Colon classification 26/09/2014
15498 S34878 Database System 16/09/2014
12578 S34879 Information Resources 22/092014
12576 S34880 MARC21 14/092014
14582 S34881 William Shakespeare 24/09/2014
12565 S34882 Library Associations 22/09/2014
14825 S34883 Business Law 15/09/2014
18
19. Relational data model :-
Advantages of Relational data Model:-
1)Structural independence.
2)Improved conceptual simplicity.
3)Easier database design, implementation, management, and use.
4)Ad hoc query capability.
5)Powerful database management system.
Advantages of Relational data Model:-
1)Substantial hardware and system software overhead.
2)Can facilitate poor design and implementation
3)May promote “islands of information "problems
19
20. Entity Relationship Models
Entity- relationship model is a logical representation of data for
an organization or for a business area .the E-R model consists of entities
which have attributes and relationships between these entities .
E-R model was proposed by peter in 1976. simply stated ,the
ER model is a conceptual data model that views the real world as entities
and relationships.
20
22. Entity Relationship Models
Advantages of Entity Relationship Models:-
1)Exceptional conceptual simplicity
2)Visual representation
3)Effective communication tool
4)Integrated with the relational data model.
Disadvantages of Entity Relationship Models:-
1)Limited constraint representation
2)Limited relationship representation
3)No data manipulation language
4)Loss of information content
22
23. Object Oriented Model
An object database (also object-oriented database
management system) is a database management system in which
information is represented in the form of objects as used in object-oriented
programming. Object databases are different from relational
databases which are table-oriented.
•Object is described by its factual content
•Includes information about relationships between facts within object and
relationships with other objects.
•Subsequent OODM development allowed an object to also contain
operations
••Object becomes basic building block for autonomous structures
23
24. Object Oriented Model
Basic structure of OODB model:-
Object: abstraction of a real-world entity.
Attributes describe the properties of an object.
Objects that share similar characteristics are grouped in classes.
Classes are organized in a class hierarchy.
Inheritance is the ability of an object within the class hierarchy to
inherit the attributes and methods of classes above it.
24
26. Object Oriented Model
Advantages of OODBMS model:-
1)Object model intuitively closer to real world
2)Extensibility – inheritance
3)Complex values
4)Removal of impedance mismatch
5)More expressive query language
6)Tight coupling between data and applications allows schema
to capture more of the meaning of applications
7) Support for long transactions
26
27. Object Oriented Model
Advantages of OODBMS model:-
8) Better support for applications like software engineering or
computer aided design (CAD)
9) Arguably better performance, though benchmarks have mainly
been applied in areas like engineering support to which OODBMS
are better suited.
Disadvantages of OODBMS model:-
1) Lack of a theoretical foundation, so exact meaning of OODM
is not well defined (though this is mitigated by the ODMG model)
27
28. Object Oriented Model
Disadvantages of OODBMS model:-
2)More difficult to get staff experienced with OODBMSs
3)Lack of standards (mitigated by ODMG's OQL)
4)Competition from relational and object-relational DBMS's
5)Encapsulation compromised to optimize queries (but in RDBMS's,
normalization may be compromised to improve performance).
6) OODBMS's usually control concurrency by locking; locking
an inheritance hierarchy is difficult and may affect performance.
28
29. Object Oriented Model
7) OODM is inherently more complex than relational data model;
OODBMS provides more complex functionality than RDBMS;
complexity leads to higher implementation and maintenance costs.
8) Lack of views; but are views necessary with an object model?
29