Database Design and Normalization Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is one of the objectives for measuring the quality of a relation schema design?

Including null values

Increasing redundancy

Enhancing complexity

Disallowing possibility of spurious tuples (correct)

A functional dependency indicates that values of attribute Y are independent of attribute X.

False

Name the first normal form (1NF) requirement regarding cell values in a table.

Each cell should contain atomic values.

The database design technique that organizes tables and reduces redundancy is called __________.

Normalization Signup and view all the answers

Match the normal forms with their characteristics:

1NF = Each cell contains atomic values 2NF = No partial dependency on the primary key 3NF = No transitive dependency BCNF = A stricter version of 3NF Signup and view all the answers

Which normal form is designed to avoid anomalies by ensuring that every attribute is fully functionally dependent on the primary key?

2NF Signup and view all the answers

Reducing the number of null values in a relation schema is a desirable outcome in database design.

True Signup and view all the answers

What is meant by 'spurious tuples' in the context of database schemas?

Unwanted rows that appear as a result of improper joins or schema design. Signup and view all the answers

What is a requirement for a table to be in Boyce Codd Normal Form (BCNF)?

It must be in 2NF Signup and view all the answers

A table in 3NF can still contain transitive functional dependencies.

False Signup and view all the answers

What is meant by 'full functional dependency' in the context of 2NF?

No partial dependency; all non-key attributes must depend on the entire primary key. Signup and view all the answers

In Fourth Normal Form (4NF), the table should not contain independent ______ facts about an entity.

multivalued Signup and view all the answers

Match the normal forms with their key requirements:

1NF = Atomic values, no duplicates 2NF = Full functional dependency, no partial FD 3NF = No transitive dependencies 4NF = No multivalued dependencies Signup and view all the answers

Which normal form requires that every non-key attribute must fully depend on the primary key?

2NF Signup and view all the answers

In 3NF, every non-key attribute must provide a fact about nothing but the key.

True Signup and view all the answers

What does Codd's rule 'the whole key' imply for 2NF?

Non-key attributes must depend on the entire primary key, not just part of it. Signup and view all the answers

What can be derived from the statement SSN → {fname, lname}?

Both A and B Signup and view all the answers

If X → YZ holds true, then it is guaranteed that both X → Y and X → Z hold true.

True Signup and view all the answers

What does the union rule state about functional dependencies?

If X → Y and X → Z hold true, then X → YZ holds true. Signup and view all the answers

Match the functional dependency with its rule:

SSN → {fname, lname} = Decomposition Rule SSN → fname = Derived from Union Rule SSN → lname = Derived from Decomposition Rule X → YZ = Union Rule Signup and view all the answers

Which of the following statements is true about the Pseudotransitivity Rule?

It requires the determination of a third attribute. Signup and view all the answers

The decomposition rule states that if A → B holds, then A must also determine any subset of B.

True Signup and view all the answers

What is the outcome of applying the union rule to the dependencies SSN → fname and SSN → lname?

SSN → {fname, lname} Signup and view all the answers

Which of the following rules allows us to infer that if set Y is a subset of set X, then X implies Y?

Reflexivity Rule Signup and view all the answers

If A → B holds, we can conclude that A, C → B holds for any set C.

True Signup and view all the answers

What is the name of the set of rules used to infer functional dependencies?

Armstrong's Axioms Signup and view all the answers

If A → B and B → C, then by the _______________ rule, A → C holds.

Transitivity Signup and view all the answers

Match the following inference rules with their descriptions:

Reflexivity = If Y is a subset of X, then X → Y Augmentation = If X → Y holds, then XC → YC also holds Transitivity = If X → Y and Y → Z hold, then X → Z Decomposition = If A → BC holds, then A → B and A → C hold Signup and view all the answers

Which inference rule states that if A → BC holds, then A → B and A → C must also hold?

Decomposition Rule Signup and view all the answers

What is the Augmentation Rule used for?

To extend functional dependencies by allowing the addition of attributes on both sides. Signup and view all the answers

The Decomposition Rule is used to combine multiple functional dependencies into one.

False Signup and view all the answers

Which type of dependency is characterized by the condition where removal of any attribute from the left side means that the dependency doesn't hold?

Full Functional Dependency Signup and view all the answers

Multivalued functional dependency is allowed in 4NF.

False Signup and view all the answers

What is the main problem with having partial dependency in a database?

It violates Second Normal Form (2NF). Signup and view all the answers

The condition where X leads to Z and Z leads to Y represents a _____ functional dependency.

transitive Signup and view all the answers

Match the following normal forms with their violations:

1NF = Multivalued Attributes 2NF = Partial Dependencies 3NF = Transitive Dependencies 4NF = Multivalued Functional Dependencies Signup and view all the answers

What is the result of a functional dependency A → C if A is not a key?

It causes redundancy. Signup and view all the answers

Partial dependencies are allowed in 2NF.

False Signup and view all the answers

How can redundancy in a database be removed?

By decomposing tables to eliminate partial and transitive dependencies. Signup and view all the answers

Multiple independent multivalued attributes in a single table create a violation of _____ form.

Fourth Normal Signup and view all the answers

Which of the following describes a violation of 1NF?

Having multiple values in a single field. Signup and view all the answers

Transitive dependencies are a requirement for Third Normal Form (3NF).

False Signup and view all the answers

What is a primary key?

A unique identifier for each record in a database table. Signup and view all the answers

The lack of primary keys in the unnormalized form can lead to _____ in the database.

redundancy Signup and view all the answers

Match the following attributes with their correct terms:

Customer Email = Multivalued Attribute Customer ID = Primary Key Product Details = Functional Dependency Order Date = Date Attribute Signup and view all the answers

Which product has the highest listed cost?

Softball-R Signup and view all the answers

Bob Smith is listed as a customer from two different addresses.

True Signup and view all the answers

What is the product manufacturer for the Bat-L?

Louisville Slugger Signup and view all the answers

The customer ID for Jill Thomas is ______.

jthomas1 Signup and view all the answers

Match the products to their respective costs:

Basketball-SP = $25 Bat-R = $45 Softball-R = $6 Golf Balls-T = $44 Signup and view all the answers

How many Basketball-SP products were ordered?

2 Signup and view all the answers

There is a duplicate entry for the product Golf Balls-T.

False Signup and view all the answers

What is the total quantity ordered for Softball-R?

2 Signup and view all the answers

The Customer Email for Bob Smith is ______.

<a href="mailto:[email protected]">[email protected]</a> Signup and view all the answers

Which of the following customers has a subscription for Baseball?

Both Bob Smith and Jill Thomas Signup and view all the answers

The product with ID Bat-R is manufactured by Rawlings.

True Signup and view all the answers

What was the order date for the second customer order?

8/10/2018 Signup and view all the answers

The total amount for order ID 3 is ______.

$23 Signup and view all the answers

Match the products to their manufacturers:

Basketball-SP = Spaulding Bat-L = Louisville Slugger Softball-R = Rawlings Golf Balls-T = Titleist Signup and view all the answers

Which customer ordered the Golf Balls-T?

Both Bob Smiths Signup and view all the answers

Study Notes

Normal Forms

Normal forms are a database design technique that organizes tables to reduce redundancy and avoid anomalies.
They are structured in a hierarchy, with 1NF at the lowest level and 4NF at the highest. Each higher form builds upon the lower ones.

Guidelines for Quality Relation Schema Design

Ensure attribute semantics are clear.
Reduce redundant information.
Minimize null values.
Eliminate spurious tuples.

Functional Dependency

A functional dependency (FD) is a constraint between two sets of attributes.
If X functionally determines Y, then every value of X must map to exactly one value of Y. Values of X uniquely define values of Y.

Formal Definition of Functional Dependency

For any two tuples t₁ and t₂ with t₁[X] = t₂[X], then t₁[Y] = t₂[Y]
In essence, if the values in attribute X are the same for two tuples, the values in attribute Y must also be the same.

Normalization

Normalization is a technique used to organize tables in a database to reduce redundancy.
It aims to reduce data anomalies and improve data integrity.
Normalization makes use of functional dependencies to ensure relations are in high normal forms.

First Normal Form (1NF)

Each cell in a table must contain atomic values.
No duplicate values are allowed within a column.
All the values in a column should belong to the same domain.

Second Normal Form (2NF)

The table must be in 1NF.
Every non-key attribute is fully functionally dependent on the primary key.
No partial dependencies exist.

Third Normal Form (3NF)

The table must be in 2NF.
Ensure that no non-key attribute is transitively dependent on the primary key.
In essence, no non-key attribute depends on another non-key attribute.

Boyce-Codd Normal Form (BCNF)

The table must be in 3NF.
Every determinant (attribute or set of attributes that determines other attributes) must be a candidate key.

Fourth Normal Form (4NF)

The table must be in BCNF.
There are no independent multi-value dependencies.

Partial Functional Dependency

A partial dependency occurs when a non-key attribute depends on only part of the primary key, not the entire key.
Not permissible in 2NF

Transitive Functional Dependency

A transitive dependency occurs when a non-key attribute depends on another non-key attribute, which in turn depends on the primary key.
Not allowed in 3NF

Multivalued Functional Dependency

A multivalued dependency happens when an attribute can take on multiple values independently without the need for multiple candidate keys or entities.
This is not permitted in 4NF.

Identifying Primary Columns

Tables typically have primary columns in each table. These determine the data integrity in the database.

Decomposing to Remove Redundancy

Decomposition involves splitting a table into smaller tables to remove redundancy and improve efficiency.
Normalization involves implementing different decompositions that improve the quality of the data scheme.

Armstrong's Axioms

A set of inference rules—reflexivity, augmentation, transitivity, decomposition, and union rules—used to infer all functional dependencies within a relational database.

IR1: Reflexivity

A set of attributes {X, Y} → X holds, assuming X ⊆ {X, Y}

IR2: Augmentation

If X → Y holds, adding attribute Z to both sides (so X, Z → Y, Z) also holds

IR3: Transitivity

If X → Y and Y → Z, then X → Z

IR4: Decomposition

If X → {YZ} then X → Y and X → Z

IR5: Union

If X → Y and X → Z, then X → {Y, Z}

IR6: Pseudotransitivity

If X → Y and WY → Z, then XW → Z

Closure

The closure F⁺ of a set of functional dependencies, F, includes all the FDs implied by F.

Chapter 14 (Database Design)

Contains information on dependencies and normal forms, along with design guidelines.

Chapter 15 (Relational Database Algorithms)

Provides information and methodologies related to inferences, algorithm design and minimal covers.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on database schema design and normalization forms with this quiz. You will explore concepts such as functional dependencies, normal forms, and the requirements for achieving different levels of normalization. Perfect for students studying database management or related fields.

Database Design and Normalization Quiz

Choose a study mode

Podcast

Questions and Answers

What is one of the objectives for measuring the quality of a relation schema design?

A functional dependency indicates that values of attribute Y are independent of attribute X.

Name the first normal form (1NF) requirement regarding cell values in a table.

The database design technique that organizes tables and reduces redundancy is called __________.

Match the normal forms with their characteristics:

Which normal form is designed to avoid anomalies by ensuring that every attribute is fully functionally dependent on the primary key?

Reducing the number of null values in a relation schema is a desirable outcome in database design.

What is meant by 'spurious tuples' in the context of database schemas?

What is a requirement for a table to be in Boyce Codd Normal Form (BCNF)?

A table in 3NF can still contain transitive functional dependencies.

What is meant by 'full functional dependency' in the context of 2NF?

In Fourth Normal Form (4NF), the table should not contain independent ______ facts about an entity.

Match the normal forms with their key requirements:

Which normal form requires that every non-key attribute must fully depend on the primary key?

In 3NF, every non-key attribute must provide a fact about nothing but the key.

What does Codd's rule 'the whole key' imply for 2NF?

What can be derived from the statement SSN → {fname, lname}?

If X → YZ holds true, then it is guaranteed that both X → Y and X → Z hold true.

What does the union rule state about functional dependencies?

Match the functional dependency with its rule:

Which of the following statements is true about the Pseudotransitivity Rule?

The decomposition rule states that if A → B holds, then A must also determine any subset of B.

What is the outcome of applying the union rule to the dependencies SSN → fname and SSN → lname?

Which of the following rules allows us to infer that if set Y is a subset of set X, then X implies Y?

If A → B holds, we can conclude that A, C → B holds for any set C.

What is the name of the set of rules used to infer functional dependencies?

If A → B and B → C, then by the _______________ rule, A → C holds.

Match the following inference rules with their descriptions:

Which inference rule states that if A → BC holds, then A → B and A → C must also hold?

What is the Augmentation Rule used for?

The Decomposition Rule is used to combine multiple functional dependencies into one.

Which type of dependency is characterized by the condition where removal of any attribute from the left side means that the dependency doesn't hold?

Multivalued functional dependency is allowed in 4NF.

What is the main problem with having partial dependency in a database?

The condition where X leads to Z and Z leads to Y represents a _____ functional dependency.

Match the following normal forms with their violations:

What is the result of a functional dependency A → C if A is not a key?

Partial dependencies are allowed in 2NF.

How can redundancy in a database be removed?

Multiple independent multivalued attributes in a single table create a violation of _____ form.

Which of the following describes a violation of 1NF?

Transitive dependencies are a requirement for Third Normal Form (3NF).

What is a primary key?

The lack of primary keys in the unnormalized form can lead to _____ in the database.

Match the following attributes with their correct terms:

Which product has the highest listed cost?

Bob Smith is listed as a customer from two different addresses.

What is the product manufacturer for the Bat-L?

The customer ID for Jill Thomas is ______.

Match the products to their respective costs:

How many Basketball-SP products were ordered?

There is a duplicate entry for the product Golf Balls-T.

What is the total quantity ordered for Softball-R?

The Customer Email for Bob Smith is ______.

Which of the following customers has a subscription for Baseball?

The product with ID Bat-R is manufactured by Rawlings.

What was the order date for the second customer order?

The total amount for order ID 3 is ______.

Match the products to their manufacturers:

Which customer ordered the Golf Balls-T?

Study Notes

Normal Forms

Guidelines for Quality Relation Schema Design

Functional Dependency

Formal Definition of Functional Dependency

Normalization

First Normal Form (1NF)

Second Normal Form (2NF)

Third Normal Form (3NF)

Boyce-Codd Normal Form (BCNF)

Fourth Normal Form (4NF)

Partial Functional Dependency

Transitive Functional Dependency

Multivalued Functional Dependency

Identifying Primary Columns

Decomposing to Remove Redundancy