Normalization_problems in Database Management Systems
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DBMS
Normalization_problems in Database Management Systems
- 1. Normalize the following into 1 NF Member id First Name Last name Hobbies 101 Jayson Mark Cricket, Swimming, Football 102 Ram Ganesh Swimming, Running, Music 103 Raj Kishore Dancing, Singing, Running To normalize the provided data into First Normal Form (1NF), we need to eliminate repeating groups and ensure that each attribute contains only atomic (indivisible) values. Original Table: Member id First Name Last name Hobbies 101 Jayson Mark Cricket, Swimming, Football 102 Ram Ganesh Swimming, Running, Music 103 Raj Kishore Dancing, Singing, Running 1NF Requirements: Atomic values (no multiple values in a single cell). Unique rows. Order of data does not matter.
- 2. Normalized Table (1NF): Member ID First Name Last Name Hobby 101 Jayson Mark Cricket 101 Jayson Mark Swimming 101 Jayson Mark Football 102 Ram Ganesh Swimming 102 Ram Ganesh Running 102 Ram Ganesh Music 103 Raj Kishore Dancing 103 Raj Kishore Singing 103 Raj Kishore Running This structure now adheres to First Normal Form (1NF) by removing the multi-valued field (Hobbies) and ensuring each field contains only one value. Let me know if you'd like this further normalized into 2NF or 3NF.
- 3. Q2. Normalize the following table in 2NF Emp No Training Training_Date Dept 101 Oracle SQL 12-Aug-2015 TT 101 Java 21-Aug-2015 BU 102 Oracle SQL 18-Sept-2014 TT Original Table Emp No Training Training_Date Dept 101 Oracle SQL 12-Aug-2015 TT 101 Java 21-Aug-2015 BU 102 Oracle SQL 18-Sept-2014 TT Step 1: Identify Partial Dependencies To be in 2NF: The table must first be in 1NF. Then, remove partial dependencies, meaning no non-prime attribute should depend on part of a composite primary key. Here, the likely composite key is (Emp No, Training) since multiple trainings can be assigned to each employee. Training_Date depends on both Emp No and Training Dept depends only on Emp No → this is a partial dependency and must be removed. Step 2: Identify the Primary Key Assuming that an employee can attend multiple trainings and may be associated with different departments per training, a composite key of (Emp No, Training) or (Emp No, Training_Date) would be used.
- 4. Decompose into 2NF Table 1: Employee Emp No Dept 101 TT 102 BU 102 TT Table 2: Training_Assignments Emp No. Training Training_Date 101 Oracle SQL 2024-08-12 101 Java 2024-08-21 102 Oracle SQL 2024-09-18 This decomposition removes the partial dependency of Dept on Emp No, achieving Second Normal Form (2NF).
- 5. Q3. Normalize the given table into Third Normal Form (3NF), Member id First Name Last name Sports Fees 101 Rajesh Chand Cricket 100 102 Jayesh Raj Hockey 80 103 Marks Dorson Football 90 To normalize the given table into Third Normal Form (3NF), we must go through each normalization stage step by step. Original Table: Member id First Name Last name Sports Fees 101 Rajesh Chand Cricket 100 102 Jayesh Raj Hockey 80 103 Marks Dorson Football 90 1NF (First Normal Form): Already satisfied — all values are atomic and no repeating groups. 2NF (Second Normal Form): The primary key is likely Member ID (it's unique). All other attributes are fully dependent on it. So the table already satisfies 2NF. 3NF (Third Normal Form): We now remove transitive dependencies (where a non-key attribute depends on another non-key attribute). In this table: Sports → Fees is a transitive dependency.
- 6. Fees depends on the Sport, not directly on Member ID. Decomposition into 3NF: Table 1: Member Member_id First_Name Last_name Sport 101 Rajesh Chand Cricket 102 Jayesh Raj Hockey 103 Marks Dorson Football Table 2: Sport_Fees Sport Fees Cricket 100 Hockey 80 Football 90 Now: All non-key attributes in each table depend only on the primary key. No transitive dependencies exist. This satisfies Third Normal Form (3NF).