Data Normalization

Correct Answer: Moving employee skills into a separate table linked by employee ID

Second Normal Form (2NF) requires that a table must be in First Normal Form (1NF) and all non-key attributes must be fully dependent on the primary key. The scenario of moving employee skills into a separate table linked by employee ID perfectly illustrates 2NF because: 1. It addresses partial dependencies by separating skills (which depend only on employee ID) into their own table 2. It maintains data integrity through proper relationship using employee ID 3. It prevents data redundancy by storing skills separately The other options are incorrect because: - Creating a composite primary key doesn't address dependency issues - Removing multi-valued attributes is related to 1NF, not 2NF - Establishing unique identifiers is a basic database concept and isn't specific to 2NF normalization The correct scenario demonstrates how to handle attributes that depend on only part of a composite key by moving them to a separate table, which is the core concept of Second Normal Form.

Correct Answer: Eliminate transitive dependencies between non-key attributes

The primary goal of Third Normal Form (3NF) is to eliminate transitive dependencies between non-key attributes. This means ensuring that non-key attributes are dependent only on the primary key, not on other non-key attributes. This is the most precise and technically accurate definition of 3NF, focusing on its specific purpose in database normalization. The other options are incorrect because: - Removing redundant data and establishing primary keys is a general normalization concept, not specific to 3NF - Ensuring attributes depend on the full composite key is actually the definition of Second Normal Form (2NF), not 3NF - Establishing unique identifiers and removing duplicates is a basic database concept that applies to First Normal Form (1NF), not specifically to 3NF

Correct Answer: Each table cell contains only a single atomic value

The fundamental characteristic of First Normal Form (1NF) is that each table cell must contain only a single atomic (indivisible) value. This means no multiple values, arrays, lists, or sets are allowed in a single cell. The correct answer emphasizes this key requirement - atomic values in each cell. This is the foundational rule that must be satisfied before proceeding to higher normal forms. The other options describe characteristics of different normal forms: The option about primary key and non-key attribute dependency describes Second Normal Form (2NF). The answer about functional dependency on complete primary key refers to Third Normal Form (3NF). The option about consistent formatting and data domain is a general database design principle, but not specifically related to First Normal Form.