21 Lecture - Normalization Summary

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21 Lecture

CS403

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Normalization Summary

Normalization is the process of organizing data in a database to reduce data redundancy and improve data integrity. The most common levels of normalization are First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). Norma


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  1. What is normalization? a. A process of organizing data in a database b. A process of inserting data in a database c. A process of deleting data from a database Answer: a What is the main purpose of normalization? a. To increase data redundancy b. To decrease data redundancy c. To increase data anomalies Answer: b Which of the following is not a common level of normalization? a. First Normal Form (1NF) b. Second Normal Form (2NF) c. Fourth Normal Form (4NF) Answer: c What is the difference between First Normal Form (1NF) and Second Normal Form (2NF)? a. 1NF eliminates partial dependencies, 2NF eliminates repeating groups b. 1NF eliminates repeating groups, 2NF eliminates partial dependencies c. 1NF eliminates transitive dependencies, 2NF eliminates partial dependencies Answer: b What is a repeating group? a. A group of attributes that are dependent on only part of the primary key b. A group of non-key attributes that are dependent on each other c. A group of key attributes that are dependent on each other Answer: b What is a partial dependency? a. An attribute that is dependent on only part of the primary key b. An attribute that is dependent on the entire primary key c. An attribute that is dependent on a non-key attribute Answer: a What is a transitive dependency? a. An attribute that is dependent on only part of the primary key b. An attribute that is dependent on the entire primary key c. An attribute that is dependent on another non-key attribute Answer: c What is the benefit of normalization? a. Increased data redundancy b. Decreased data integrity c. Improved data integrity Answer: c Can a database be over-normalized? a. Yes, it can result in slower performance and more complex database designs b. No, normalization always leads to improved database performance c. It depends on the size of the database Answer: a What is an anomaly in a database? a. A normal occurrence in a database b. A situation where data does not conform to the rules of normalization c. A situation where data is not entered correctly into a database Answer: b



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  1. What is normalization? Normalization is a process of organizing data in a database to reduce data redundancy and improve data integrity. What are the common levels of normalization? The common levels of normalization are First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). What is a repeating group in a database? A repeating group is a group of non-key attributes that are dependent on each other. What is a partial dependency? A partial dependency is an attribute that is dependent on only part of the primary key. What is a transitive dependency? A transitive dependency is an attribute that is dependent on another non-key attribute. Why is normalization important? Normalization is important because it helps to improve data integrity, reduce data redundancy, and make the database more efficient. Can a database be over-normalized? Yes, a database can be over-normalized, which can result in slower performance and more complex database designs. What is the difference between First Normal Form (1NF) and Second Normal Form (2NF)? 1NF eliminates repeating groups, while 2NF eliminates partial dependencies. What is denormalization? Denormalization is the process of intentionally introducing redundancy into a database to improve performance. What are the benefits of normalization? The benefits of normalization include improved data integrity, reduced data redundancy, and a more efficient database design.

Normalization is a process of organizing data in a database to reduce data redundancy and improve data integrity. The main goal of normalization is to create a well-structured database that can efficiently handle data without any inconsistencies. The common levels of normalization are First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). In 1NF, each table cell should hold a single value, and there should be no repeating groups of data. This means that all data in a table must be atomic, meaning it cannot be divided into smaller pieces. Repeating groups must be eliminated, which can be achieved by creating new tables. In 2NF, the database is further normalized by eliminating partial dependencies. Partial dependency occurs when a non-key attribute depends on only part of the primary key. To eliminate partial dependencies, we need to create a new table for each dependent attribute. In 3NF, the database is normalized by eliminating transitive dependencies. A transitive dependency occurs when an attribute is dependent on another non-key attribute. To eliminate transitive dependencies, we need to create a new table for each attribute that is dependent on another non-key attribute. Normalization helps to improve data integrity, reduce data redundancy, and make the database more efficient. However, it is important to note that a database can be over-normalized, which can result in slower performance and more complex database designs. Denormalization is the process of intentionally introducing redundancy into a database to improve performance. In summary, normalization is a critical aspect of database design that ensures that data is efficiently stored, accessed, and manipulated. The process of normalization helps to create a well-structured database that is easy to maintain and update, while also reducing the chances of data inconsistencies.

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