Schema vs Instance, Data Independence, Degree vs Cardinality, and Database Keys Explained
1. Schema vs Instance — 6 Marks
A schema is the logical structure or design of a database. It describes tables, attributes, relationships and constraints.
Example: Student(Rollno, Name, Branch, Marks)
This structure is the schema.
Instance
An instance is the actual data stored in the database at a particular moment.
Example:
| Roll No | Name | Branch | Marks |
|---|---|---|---|
| 101 | Rahul | CSE | 78 |
| 102 | Amit | CSE | 85 |
This actual data represents an instance.
Difference Between Schema and Instance
| Schema | Instance |
|---|---|
| Structure/design of database | Actual data |
PWD, Architectural Education and Modernism in India: A Complete Study Resource
PWD and the Early Institutionalisation of Architecture in India
The Public Works Department (PWD) developed during the British period to undertake and control major public infrastructure and construction works.
The expansion of the British administration, railways, roads, canals and other infrastructure created a demand for trained technical personnel.
The PWD expanded significantly around 1854–55, becoming an important institution for surveying, planning and construction.
Its major functions included
Ethos in Early American Writing: Winthrop, Washington, and Madison
Credibility as Persuasion in Early American Writing
In his Rhetoric, Aristotle claimed that “character may almost be called the most effective means of persuasion.” Each of the early American writers knew and utilized this opportunity, but they approached it differently. All of them gained credibility for their speeches and writings, but in different manners. While John Winthrop appealed to the deity, George Washington created credibility with his arguments, and James Madison concealed his identity
Read MoreEnglish Exam Strategies: Discourse Links, Signalling Words and Hedging
1. Required Answer Structure
Memorise these phrases:
To define: “X refers to…” / “X means that…”
To exemplify: “For example,…” / “For instance,…”
Mandatory formula: Name the concept + define it in English + give the example (Definition → Explanation → Example).
2. The 5 Features of Academic Language
- Complexity: Complex grammar and lexical density. (E.g.: union reaction instead of how the unions will react).
- Formality: No colloquial language or contractions. (E.g.: cannot instead of can’t).
- Objectivity:
International Business: Environment, Trade Theories, Globalization and WTO Explained
1. International Business
International Business refers to business activities involving the exchange of goods, services, capital, technology and resources between two or more countries.
Nature / Features
- International transactions: Business takes place across national borders.
- Large market: Firms can serve customers in different countries.
- Different environments: Political, economic, legal and cultural conditions differ.
- Foreign exchange: Different currencies are involved.
- Higher risk: Political instability,
Brat Farrar by Josephine Tey: Plot, Characters and Themes Explained
1. ¿Quién es Brat Farrar? / Who is Brat Farrar?
Brat Farrar is a young English orphan who has had a difficult and lonely life. He is very good with horses. After an accident leaves him with a permanent limp, he returns to England. There he meets Alec Loding, who discovers that Brat looks very much like Patrick Ashby and asks him to pretend to be Patrick.
2. ¿Por qué Brat acepta hacerse pasar por Patrick Ashby? / Why does Brat agree to pretend to be Patrick Ashby?
At first, Brat does not want to
Read MoreBrat Farrar Novel Summary: Identity, Lies and Family Secrets
1. Who is Brat Farrar? Who is Brat Farrar?: Brat Farrar is a young man who has grown up without a family. He has travelled a lot and has always had a difficult life. He is especially talented with horses. When he returns to England, he meets Alec Loding, who notices that Brat looks almost exactly like Patrick Ashby.
2. Why does Brat agree to pretend to be Patrick Ashby? Why does Brat agree to pretend to be Patrick Ashby?: Brat accepts because he is attracted to the idea of having a home and people
Read MoreSecularism in India: Gandhi, Nehru, Ambedkar and Beyond
Introduction
Secularism in India is different from the strict separation of religion and state associated with some Western models. India is a religiously diverse society, and therefore the Constitution attempts to maintain religious freedom while also allowing the state to intervene when religion conflicts with equality, social reform and fundamental rights.
The Indian debate on secularism can broadly be understood through different perspectives: Gandhian secularism, Nehruvian secular-liberalism,
Read MoreNGRBC Principles, Marketing Mix, and CRM: Key Business Concepts
NGRBC Principles
The NGRBC are based on nine principles:
- Ethics and transparency – Businesses should conduct themselves with integrity, transparency, and accountability.
- Sustainable goods and services – Businesses should provide products and services that are safe, sustainable, and beneficial to society.
- Employee well-being – Businesses should respect employees’ rights and provide a safe, healthy, and supportive workplace.
- Stakeholder interests – Businesses should respect and respond to the interests
Heart Transplants and Air Fresheners: Health Facts and Vocabulary
Key Vocabulary: Health and Medicine
Hypertension / high blood pressure
Income / the money a person or company receives in a certain period of time.
Developed / having an advanced economy and a high standard of living.
Decent / of an acceptable standard
Cardiac / relating to the heart.
Significantly / in a way that is important and has an effect.
Severe / very serious
Transplant / an operation in which an organ from one person is put in another person’s body.
Declare / say or state something officially
Temporary
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