All About Multivaluated Dependency

Duration: 8 min

This video lesson is available to enrolled students.

Return to /learn/ISRO/database-management-system/decomposition-properties-4nf/multivalued-dependency-mvd-4nf/asset-all-about-multivaluated-dependency after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. General Aptitude & Reasoning: Number System, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Speed Time and Distance, Mixture and Alligation, Data Interpretation, Algebra, Probability, Permutation and Combination, Venn Diagram, HCF LCM, Divisibility Rules, Age Problems, Pipe and Cistern, Partnership, Linear Algebra, Sequence and Series (Series), Statistics, Powers and Exponents (Surds and Indices), Arithmetic, Mensuration and Geometry, Calculus, Trigonometry, Vectors, Speed Mathematics and Basic Mathematics, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Analogy, Series (Number and Letter Series) (Numerical Relations and Reasoning), Puzzle Solving (Puzzles), Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Calendar, Seating Arrangements, Coding Decoding, Blood Relations, Directions (Direction Test), Clock, Analytical Reasoning (Counting Figures Reasoning), Ranking, Order and Sequence, Logical Sequence Of Words, Inequality, Data Sufficiency, Cubes & Dices
  3. Computer Networks & Cybersecurity: 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
  4. Programming, Data Structures & Algorithms: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  5. AI, Machine Learning, Big Data & Cloud: Emerging Tech Trends, Artificial Intelligence, Big Data Systems, Approaches to AI, Search Algorithms, Knowledge Representation, Cloud Computing
  6. Digital Logic & Computer Organization: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. TOC & Compiler: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  8. Discrete Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic
  9. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Distributed Systems
  10. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Object Oriented Technology, HTML Basics, JavaScript-Basics, Java, XML
  11. Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Data Warehousing & Mining, Enhanced Data Models, NoSQL
  12. Other Recurring CS Topics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, Multimedia
  13. Live Classes: ISRO Live classes
  14. Full Mock Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture introduces Multivalued Dependencies (MVDs) as a consequence of First Normal Form (1NF) restrictions, which disallow attributes from having sets of values. The instructor defines the notation $A woheadrightarrow B$ and distinguishes it from functional dependencies using a table example. The concept of trivial MVDs is explained, where the right-hand side is a subset of the left-hand side or they form the entire relation. Finally, a detailed example of a Student relation demonstrates how MVDs cause redundancy even when a schema is in BCNF, illustrating the cross-product effect of independent multivalued attributes.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video begins with the title 'Multivalued Dependency' on the slide. The first bullet point states that MVDs are a 'consequence of first normal form (1NF) which disallows an attribute in a tuple to have a set of values'. The instructor introduces the notation $A woheadrightarrow B$, explaining it means 'for every value of A, there may exist more than one value of B'. He writes $A ightarrow B$ on the screen, then corrects it to $A woheadrightarrow B$. He draws a table with columns A and B, populating it with values: 1 maps to a, 2 maps to a, and 1 maps to b. This visual demonstrates that for A=1, there are multiple values of B (a and b), which is characteristic of a multivalued dependency rather than a functional dependency.

  2. 2:00 – 5:00 02:00-05:00

    The lecture transitions to 'trivial multivalued dependency'. The slide text defines this as a dependency $X woheadrightarrow Y$ where 'either Y is a subset of X, or X and Y together form the whole set of attributes of the relation'. The instructor writes 'T' for Trivial and 'NT' for Non-Trivial. He provides an example $AB woheadrightarrow B$, labeling AB as LHS and B as RHS. He writes the condition $RHS \subseteq LHS$ to show that if the right-hand side is a subset of the left-hand side, the dependency is trivial. He draws a table with columns X and Y to visualize this relationship, reinforcing that if Y is contained within X, the dependency holds trivially.

  3. 5:00 – 7:33 05:00-07:33

    The instructor presents a concrete example using a relation named 'Student'. The slide lists two constraints: $S\_name woheadrightarrow Club\_name$ and $S\_name woheadrightarrow P\_no$. He shows two decomposed tables: one linking Kamesh to Dance and Guitar, and another linking Kamesh to phone numbers 123 and 789. He then displays a combined table with columns S_Name, Club_name, and P_no. He explains that because the club names and phone numbers are independent multivalued attributes, the combined table must contain the cross-product of these values. This results in four rows: (Kamesh, Dance, 123), (Kamesh, Guitar, 123), (Kamesh, Dance, 789), and (Kamesh, Guitar, 789). He circles the P_no values 123 and 789 to highlight the repetition. A note at the bottom states the schema is in BCNF but still has redundancy due to MVD.

The lesson progresses from the theoretical definition of Multivalued Dependencies as a consequence of 1NF to the specific notation $A woheadrightarrow B$. It clarifies the distinction between functional and multivalued dependencies through visual table examples. The concept of trivial MVDs is then defined based on subset relationships between attributes. Finally, the practical implication of MVDs is demonstrated using a Student relation, showing how independent multivalued attributes create a cross-product effect that leads to data redundancy, even in a BCNF schema.

Loading lesson…