DBMS PRACTICE QUESTIONS

Duration: 5 min

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Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Mensuration and Geometry, Age Problems, Arithmetic, Statistics, Probability, Profit and Loss, Simple Interest and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, Powers and Exponents (Surds and Indices), Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy
  3. Paper-1 & 2 | Data Interpretation: Data Interpretation
  4. Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
  5. Paper-1 & 2 | Logical Reasoning and Analytical Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Analogy, Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Arrangement, Logical Sequence Of Words, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: Selection Decision Table (Decision Making)
  7. Paper-1 | General Science: Physics, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: State Wise GK, GK- Current Affairs
  9. Paper-2 | Fundamentals of Computer: Basics of COA, Number System, Floating Point Rep, Number Representation
  10. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits
  11. Paper-2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Linux OS, Distributed Systems
  12. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Relational Calculus, File Organization & Indexing, Transaction Management, Concurrency Control
  13. Paper-2 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  15. Paper 2 | Oops, C++, Java: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  16. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  17. Paper 2 | Emerging Trends and AI: Emerging Tech Trends, Artificial Intelligence
  18. Paper-2 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Advanced Algorithms
  19. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Ethical Hacking
  20. Paper-2 I Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  21. Paper-2 | Computer Organization and Architecture: Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations
  22. Paper-2 | Web Development: JavaScript-Basics, HTML Basics, CSS, XML
  23. Pedagogy: Child Development, Concept of Pedagogy, Psychology, Theories, Inclusive Education, Experiential Pedagogy, Curriculum Framework & Reforms, National Education Policy (NEP) 2020
  24. Live Sessions: RSSB Live Sessions
  25. RSSB Paper 1 - Full Mock Tests:
  26. RSSB Paper 2 - Full Mock Tests:
  27. SCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video is an educational lecture on database theory, specifically focusing on the process of finding candidate keys for a relational schema. The problem presented is R(WXYZ) with a set of functional dependencies: X -> W, WZ -> XY, and Y -> WXZ. The instructor systematically applies the attribute closure method to determine which attribute sets can function as candidate keys. He begins by testing individual attributes and small combinations, calculating their closures to see if they encompass all attributes in the relation. The lecture progresses from identifying obvious keys to using heuristics for finding multiple candidate keys, culminating in a final list of keys.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor starts by writing the problem statement "Q. R(WXYZ) Find candidate key" and listing the functional dependencies: X -> W, WZ -> XY, and Y -> WXZ. He begins the analysis by calculating the closure of X, denoted as X+, which he writes as {X, W}. He notes that this is not a superkey because it lacks Y and Z. Next, he calculates the closure of the combination WZ, writing (WZ)+ = {W, X, Z, Y}. He identifies this as a Super Key (SK) and a Candidate Key (CK). He then checks the subsets W and Z, writing W+ = {W} and Z+ = {Z}, marking them as not keys. Finally, he calculates the closure of Y, writing Y+ = {Y, W, X, Z}, identifying Y as a Candidate Key. He summarizes the candidate keys found so far as {Y, WZ}.

  2. 2:00 – 4:30 02:00-04:30

    The instructor moves on to discuss finding multiple candidate keys. He writes a rule on the board: "To find multiple CKs: X -> PA then X must be apart of any CK". He identifies the Prime Attributes (PA) as {W, Y, Z}. He then explores the combination XZ. He reasons that since X -> W, the set XZ can derive WZ. Since WZ -> XY, XZ can derive all attributes. He writes "CK {Y, WZ, XZ}" on the board. He also writes "X -> Y" and crosses out "X -> W", possibly correcting a dependency or exploring a relationship, but the final boxed answer clearly lists Y, WZ, and XZ as the candidate keys. He boxes the final answer "CK {Y, WZ, XZ}" to conclude the problem.

The lecture provides a clear, step-by-step demonstration of finding candidate keys using attribute closure. It covers the initial identification of keys through direct calculation and then introduces a heuristic method to find additional keys involving prime attributes. The instructor uses board writing to visually track the closure calculations and the final set of candidate keys, ensuring students can follow the logical progression from functional dependencies to the final solution.

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