Update Anomalies In Relational Model

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/COGNIZANT-PREPARATION/dbms/relational-model-functional-dependencies/basics-of-relational-model-anomalies/asset-update-anomalies-in-relational-model after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Communication Round: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Direct and Indirect Speech, Active Passive Voice (Voice), Verbal Analogy (Word Based Analogy), Articles, Preposition, Conjunction, Sentence Construction, English Writing Ability, Communication Assessment
  2. Quantitative Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Age Problems, Pipe and Cistern, Probability, Profit and Loss, Simple Interest and Compound Interest, Algebra
  3. Analytical and Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Puzzle Solving (Puzzles), Syllogisms, Seating Arrangements, Calendar, Clock, Blood Relations, Cubes & Dices, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning)
  4. Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
  5. Java (Cluster 1): Java
  6. ANSI SQL MySQL (Cluster 1,2,3): SQL
  7. HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
  8. Python (Cluster 2): Python for Placements by Yash Sir
  9. Cloud Fundamentals (Cluster 2): Emerging Tech Trends
  10. C# (Cluster 3): C#
  11. OOPs: Object Oriented Programming (OOPS)
  12. Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
  13. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  15. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  16. Computer Networks: 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
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video lecture addresses critical problems in relational database design, specifically focusing on data anomalies that occur due to poor normalization. The instructor introduces three main types of anomalies: Update, Insertion, and Deletion. Using a sample relational table containing student details (Roll no, name, Age) and branch details (Br_code, Br_name, Br_hod_name), the lecture demonstrates how redundancy leads to inefficiency and data integrity issues. The visual aid includes a table with four rows of data, which the instructor annotates with red circles and lines to highlight specific problematic areas.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The session begins with the definition of Update Anomalies, described as anomalies causing redundant work during insertion and modification, potentially leading to accidental information loss during deletion. The instructor points to the provided table, which lists student roll numbers, names, ages, and associated branch codes and names. He specifically highlights the redundancy in the first three rows where the branch code 101, branch name Cs, and head of department Abc are repeated. By circling these values in red, he illustrates that if the branch name changes, it must be updated in multiple rows, creating unnecessary work and the risk of inconsistent data if one update is missed.

  2. 2:00 – 5:00 02:00-05:00

    The lecture transitions to Insertion Anomalies, defined as the inability to record an independent piece of information unless irrelevant information is inserted simultaneously. The instructor explains that in the current table structure, one cannot simply add a new branch (like branch 102, named Ec with head Pqr) without also adding a student record. He points out that branch details are dependent on student records in this schema. He writes R3 and AE under the table, likely referring to specific rows or attributes to emphasize that branch information cannot exist independently. This forces the insertion of irrelevant student data just to store branch details, violating database design principles.

  3. 5:00 – 5:33 05:00-05:33

    The final segment covers Deletion Anomalies, defined as the unintentional removal of other information when deleting a piece of data. The instructor demonstrates this by crossing out the entire fourth row, which contains student D and branch 102. He explains that if student D leaves the institution and their record is deleted, the information regarding branch 102 (Ec, Pqr) is also lost because it was only stored in that specific row. This highlights the critical flaw of storing branch details within a student table, as deleting a student inadvertently deletes the branch data.

The video effectively demonstrates the necessity of normalization in database design. By analyzing a single unnormalized table, the instructor shows how Update, Insertion, and Deletion anomalies compromise data integrity and efficiency. The visual annotations clearly link theoretical definitions to practical examples, reinforcing the need to separate entities like students and branches into distinct tables to avoid these common relational database problems.

Loading lesson…