What Is Trivial Functional Dependency

Duration: 4 min

This video lesson is available to enrolled students.

Return to /learn/HEXAWARE-PREPARATION/dbms/relational-model-functional-dependencies/functional-dependencies-axioms/asset-what-is-trivial-functional-dependency after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Ability: Speed Mathematics and Basic Mathematics, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Speed Time and Distance, Number System, HCF LCM, Data Interpretation, Age Problems, Mixture and Alligation, Partnership, Algebra, Sequence and Series (Series), Mensuration and Geometry, Arithmetic
  2. Reasoning Ability: Puzzle Solving (Puzzles), Seating Arrangements, Coding Decoding, Blood Relations, Directions (Direction Test), Syllogisms, Data Sufficiency, Ranking, Order and Sequence, Series (Number and Letter Series) (Numerical Relations and Reasoning), Logical Sequence Of Words, Calendar, Clock, Cubes & Dices, Analytical Reasoning (Counting Figures Reasoning), Data Arrangement, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning)
  3. Verbal Ability: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Vocabulary, Sentence Completion (Fill in the blanks), Active Passive Voice (Voice), Direct and Indirect Speech, Subject Verb Agreement (Verb Noun Agreement), Tenses, Preposition, Articles, Sentence Correction (Error Correction)
  4. Programming Basics (MCQs + Interview): C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  5. OOPs (MCQs + Interview): Object Oriented Programming (OOPS)
  6. DBMS (MCQs + Interview): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Transaction Management, Decomposition Properties & 4NF, Concurrency Control, Database Recovery, File Organization & Indexing, Relational Algebra, Database Security & Authorization
  7. SQL (MCQs + Interview): SQL
  8. Operating Systems (MCQs + Interview): Introduction to OS, Process Management, CPU Scheduling, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Process Synchronization, Disc Scheduling, File Management, Security
  9. Computer Networks (MCQs + Interview): Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, 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, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
  10. Coding: Coding Questions by Yash Sir
  11. HR Interview: MR & HR Interview Preparation
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a clear explanation of Trivial Functional Dependency within the context of Database Management Systems. The instructor starts by defining the concept: a functional dependency alpha -> beta is trivial if beta is a subset of alpha. He uses visual aids, including a table and handwritten notes, to illustrate that knowing the superset automatically provides the subset. The lecture then applies this theory to a multiple-choice question from the GATE 2016 exam. The problem involves a relation with attributes P, Q, R, S, T, and U. The instructor systematically evaluates the given options to find the dependency where the right-hand side is a subset of the left-hand side, ultimately selecting {P, S} -> {S} as the trivial dependency. He emphasizes that this holds true regardless of the specific data values in the relation.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by defining Trivial Functional Dependency. The slide states: 'If beta is a subset of alpha, then the functional dependency alpha -> beta will always hold.' He emphasizes this concept with Hindi text 'जिसका होना न होना बराबर हो,' translating to 'whatever happens or doesn't happen is equal,' implying the dependency is always true. He writes the example XY -> X on the screen, circling it in red to show that X is a subset of XY. He further formalizes this with the notation beta subset alpha and alpha -> beta, marking the dependency as 'valid' and 'trivial.' He also points to a data table with columns X, Y, and Z to provide context for how attributes relate, although the primary focus remains on the abstract definition.

  2. 2:00 – 3:40 02:00-03:40

    The lecture transitions to a specific problem from GATE 2016. The slide presents a relation X(P, Q, R, S, T, U) with a set of functional dependencies F = { {P, R} -> {S, T}, {P, S, U} -> {Q, R} }. The question asks to identify the trivial functional dependency in the closure of F. The instructor reviews the options: (a) {P, R} -> {S, T}, (b) {P, R} -> {R, T}, (c) {P, S} -> {S}, and (d) {P, S, U} -> {Q}. He identifies option (c) as the correct answer because the attribute S on the right side is a subset of the attributes {P, S} on the left side. He writes {P, S} -> {S} on the screen to reinforce the logic, circling the option to highlight the solution.

The lesson effectively bridges theory and practice. It begins with a rigorous definition of trivial functional dependencies, using set notation and Hindi explanations to ensure clarity. It then immediately applies this definition to a standard exam problem, demonstrating how to spot the subset relationship in a list of complex functional dependencies. This progression helps students understand not just the 'what' but the 'how' of identifying trivial dependencies in database normalization tasks.

Loading lesson…