SPPU DBMS Important Questions - Brief Exam
Notes
1. Advantages of DBMS over File System
Reduces redundancy, improves integrity, security, data sharing, backup/recovery and supports
multi-user access.
2. Data Abstraction and Levels
Physical level (how data stored), Logical level (what data stored), View level (user-specific view).
3. Data Independence
Ability to change schema without affecting applications. Types: Logical and Physical.
4. ER Model Components
Entity, Attribute, Relationship. Converted into tables using keys and foreign keys.
5. Keys in DBMS
Primary Key uniquely identifies records; Foreign Key links tables; Candidate Key can become
primary key.
6. Normalization
Organizes data to remove redundancy. 1NF removes repeating groups, 2NF removes partial
dependency, 3NF removes transitive dependency.
7. Normalization vs Denormalization
Normalization improves consistency; Denormalization improves performance.
8. ACID Properties
Atomicity, Consistency, Isolation, Durability ensure reliable transactions.
9. DBMS Security Challenges
Unauthorized access, SQL injection, data theft. Solutions: authentication, authorization, encryption.
10. Concurrency Control
Manages simultaneous transactions using locking, timestamps and MVCC.
11. EER Model
