Database Management System (BSc CSIT, CSC260): the questions likely to come
30 analyzed questions from 7 past papers (2074-2081), grouped by syllabus unit — each with its probability, how often it's been asked, and where to study the answer.
What is a trigger? Explain with an example.
Trigger
A trigger is a special stored procedure that is automatically executed (fired) by the DBMS in response to a specified event (INSERT, UPDATE, or DELETE) on a table or view. Triggers are used to enforce business rules, maintain integrity constraints, audit changes, and automatically update related data.
Classification:
- By timing: BEFORE or AFTER the triggering event.
- By granularity: row-level (
FOR EACH ROW) or statement-level. - Pseudo-records
OLD(existing values) andNEW(new values) reference the affected row.
Example (audit on salary change):
CREATE TRIGGER salary_audit
AFTER UPDATE OF salary ON Employee
FOR EACH ROW
BEGIN
INSERT INTO Salary_Log(empno, old_sal, new_sal, changed_on)
VALUES (:OLD.empno, :OLD.salary, :NEW.salary, SYSDATE);
END;
Whenever an employee's salary is updated, this trigger fires automatically and records the old value, new value, and timestamp in Salary_Log — without any explicit call from the application.
SQL
What is a trigger? Explain with an example.
Differentiate between the DELETE, DROP, and TRUNCATE commands.
Explain aggregate functions in SQL with examples.
Explain indexing in databases. Differentiate between primary, secondary, and clustering indexes, and explain the structure of a B+ tree index.
Explain the concept of a stored procedure.
Explain SQL with examples. Write SQL queries to create tables, insert data, and perform join, group by, and nested subquery operations on a given schema.
What is a join? Explain inner join and outer join.
What is a view in SQL? Explain its advantages.
Sit a probable paper
A full mock exam built from the most likely questions, mirroring the real paper's structure. Every slot is a real past question.
Most Probable Paper
Mirrors the real structure · 60 marks · based on 7 past papers
- 1.[10 marks]
Define a transaction and explain its ACID properties. Discuss the various states of a transaction with a state diagram.
This question has recurred in 3 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 4 of 7 years.
- 2.[10 marks]
Explain Boyce-Codd Normal Form (BCNF). Differentiate it from 3NF and decompose a given relation into BCNF with an example.
This question has recurred in 2 of 7 years; so far only in internal assessments, not the board; and its topic (Relational Database Design) appears in 100% of years.
- 3.[10 marks]
What is normalization? Explain 1NF, 2NF, and 3NF with suitable examples, and discuss why normalization is necessary.
This question has recurred in 2 of 7 years; so far only in internal assessments, not the board; and its topic (Relational Database Design) appears in 100% of years.
- 1.[5 marks]
What is a trigger? Explain with an example.
This question has recurred in 5 of 7 years; so far only in internal assessments, not the board; and its topic (SQL) appears in 100% of years.
- 2.[5 marks]
Differentiate between the DELETE, DROP, and TRUNCATE commands.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (SQL) appears in 100% of years.
- 3.[5 marks]
Explain aggregate functions in SQL with examples.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (SQL) appears in 100% of years.
- 4.[5 marks]
What is data redundancy? How does normalization reduce it?
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (Relational Database Design) appears in 100% of years.
- 5.[5 marks]
Explain lossless join and dependency-preserving decomposition.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic (Relational Database Design) appears in 100% of years.
- 6.[5 marks]
Explain the concept of a weak entity set with an example.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 5 of 7 years.
- 7.[5 marks]
Differentiate between relational algebra and relational calculus.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 5 of 7 years.
- 8.[5 marks]
Define schedule. Differentiate between serial and serializable schedules.
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 4 of 7 years.
- 9.[5 marks]
What is a deadlock in a database? How is it handled?
This question has recurred in 4 of 7 years; so far only in internal assessments, not the board; and its topic recurs in 4 of 7 years.
Behind the numbers
The raw evidence the predictions are computed from: marks per unit per year, syllabus weights, trends, and coverage.
Show the heatmap, topic table and coverage analysis
The receipt: marks per unit, per year
Each row is a syllabus unit, each column an exam year, each cell the marks that unit earned that year. Click any cell to see the actual questions behind it.
| # | Syllabus unit | Probability | Appeared | Avg marks | Syllabus weight | Exam vs syllabus | Trend | Questions |
|---|---|---|---|---|---|---|---|---|
| 1 | U6SQL | Very likely100% | 18.6 | 18%8 lecture hrs | Over-examinedexam 25% · syllabus 18% | Steady | 6 recurring8 total | |
| 2 | U7Relational Database Design | Very likely100% | 17.9 | 16%7 lecture hrs | Over-examinedexam 24% · syllabus 16% | Steady | 6 recurring7 total | |
| 3 | U3Data Modeling Using the Entity-Relational Model | Likely71% | 10 | 13%6 lecture hrs | Balancedexam 10% · syllabus 13% | Steady | 3 recurring3 total | |
| 4 | U5The Relational Algebra and Relational Calculus | Likely71% | 8 | 11%5 lecture hrs | Balancedexam 8% · syllabus 11% | Steady | 2 recurring2 total | |
| 5 | U8Introduction to Transaction Processing Concepts and Theory | Likely57% | 12.5 | 9%4 lecture hrs | Balancedexam 10% · syllabus 9% | Steady | 2 recurring2 total | |
| 6 | U1Database and Database Users | Likely57% | 11.2 | 4%2 lecture hrs | Balancedexam 9% · syllabus 4% | Steady | 3 recurring3 total | |
| 7 | U9Concurrency Control Techniques | Likely57% | 10 | 9%4 lecture hrs | Balancedexam 8% · syllabus 9% | Steady | 2 recurring2 total | |
| 8 | U4The Relational Data Model and Relational Database Constraints | Possible43% | 5 | 7%3 lecture hrs | Balancedexam 3% · syllabus 7% | Steady | 1 recurring1 total | |
| 9 | U10Database Recovery Techniques | Occasional29% | 10 | 7%3 lecture hrs | Balancedexam 4% · syllabus 7% | Steady | 1 recurring1 total | |
| 10 | U2Database System – Concepts and Architecture | Occasional14% | 10 | 7%3 lecture hrs | Balancedexam 2% · syllabus 7% | Fading | none repeat1 total |
Study smart, not hard
Drag the slider: studying the top 6 units in priority order covers ~84% of all observed marks.
- ~80% line
Lecture time vs exam marks
Where the exam pays more than the curriculum spends: ● lectures vs ● exam marks, as a share of the whole course. A long teal-leading bar = high-yield unit.