WGU D427 Practice Questions

In which normal form are all non-key attributes fully functionally dependent on the primary key?

3NF

Which symbol represents a one-to-many relationship in ER Diagrams?

A crow's foot

What is an attribute in the context of ER modeling?

A descriptive property or characteristic of an entity

What represents a relationship in an ER Diagram?

A line connecting entities

What is an entity in an ER model?

A person, place, product, concept, or activity

To combine two or more columns or strings into a single string in SQL, you would use:

CONCAT()

To find the number of non-NULL rows in a column, you would use:

COUNT()

Which SQL command is used to create a new table?

CREATE TABLE

Which SQL function returns the current date?

CURDATE()

The IN operator is used in a WHERE clause to:

Check if a value matches any value in a list

What does the query processor layer in MySQL do?

Compiles queries into low-level instructions

What is a composite attribute?

An attribute that can be divided into smaller parts, each representing a more basic attribute

What does a unique attribute signify in ER modeling?

An attribute that identifies each entity instance uniquely

Which of the following best describes a strong entity?

An entity that has a unique identifying attribute

What is an associative entity?

An entity that is used to represent a many-to-many relationship with attributes

Which SQL command is used to delete a table?

DROP TABLE

What describes data in terms of scope, format, and access?

Data Characteristics

What is intersection data in an ER Diagram?

Data that describes the relationship between two entities

What does the 'many' in a 1-M relationship imply?

No exact numerical limit but more than one

In ER modeling, what describes the relationship between a salesperson and an office space/cubicle?

One-to-One

What is the main advantage of a sorted table?

Optimal for queries that read data in sort order

Which constraint ensures uniqueness in a table's column?

PRIMARY KEY

Which of the following is NOT a characteristic of column-oriented storage?

Performs best for transactional applications

What is a significant disadvantage of table clusters for certain queries?

Performs poorly for joins on non-cluster key columns

Which layer of MySQL architecture manages connections from multiple users?

Query processor

_______________ ensures the consistency and validity of relationships between tables. It dictates that foreign key values in one table must either be null or match primary key values in another table (or the same table in the case of self-referencing relationships)

Referential integrity

To calculate the square root of a number in SQL, you would use:

SQRT()

The LIKE operator is used to:

Search for a specified pattern in a column

What is a primary feature of relational databases?

Tables

What does the cardinality of a relationship indicate?

The maximum and minimum number of entity instances that can be involved in a relationship

What does modality represent in an ER Diagram?

The minimum number of entity occurrences that can be involved in a relationship

Which statement about NoSQL databases is true?

They are optimized for big data

What is the purpose of an ER Diagram?

To visually represent the data model of a system

What describes the 'heap table' structure's approach to managing free space after row deletion?

Tracks free space as a linked list for future inserts

What is the term for a row in a relational database?

Tuple

How does a hash table determine the bucket containing each row?

Using a hash function and hash key

Which SQL clause is used to filter rows in a SELECT statement?

WHERE

How are weak entities represented in an ER Diagram?

With a double rectangle

Which SQL statement is used to remove rows of data from a database?

DELETE

Consider the following database table Order with the following columns: OrderID (Primary Key) CustomerID CustomerName OrderDate ProductID ProductName Quantity Which of the following normal forms does the Order table currently satisfy IF: 1) Each OrderID has a unique value (i.e. is a primary key) 2) Each entry in the table is atomic (no repeating groups or arrays).

First Normal Form

MySQL architecture is organized into how many layers?

Four

In which type of table is no specific order imposed on rows?

Heap table

The MySQL Enterprise Edition includes components for:

High-end commercial installations, like backup and security

In SQL, which command is used to add a row of new data into a table?

INSERT INTO

What characterizes a table cluster?

Interleaves rows of two or more tables in the same storage area.

Which operation combines rows from two tables based on related columns?

JOIN

To convert a string to lower case in SQL, which function is used?

LOWER()

Which function would you use to find the least/lowest value in a set?

MIN()

Which storage media has the fastest access time?

Main memory (RAM)

What is a primary function of a Database Management System (DBMS)?

Managing database security and access

Which term describes the process of denormalization?

Merging Tables

Which normal form removes partial dependencies?

2NF

MySQL Workbench is designed for:

Both database administrators and users

What is a binary relationship in ER modeling?

A relationship between two entity types

Which of the following best represents a ternary relationship?

A relationship involving three different entity types

In a unary relationship, what kind of relationship is described?

A relationship where an entity is related to itself

A column in Table B has been indexed? Which action would cause the index to be updated?

A row is deleted from Table B

What is the result of a SELECT statement?

A set of tuples

What is a datbase?

A structured collection of data

The GROUP BY statement is used to:

Aggregate rows of data based on a common criteria

What does the Audit component in MySQL Enterprise Edition track?

All database changes, including time and user details

The BETWEEN operator checks if a value is:

Between an inclusive range of two values

Which relationship involves a salesperson and products they sell?

Binary

What does CRUD stand for in the context of database operations?

Create, Read, Update, Delete

Which of the following best describes the role of a database administrator?

Designs the physical layout of data, Secures the database against unauthorized access , Monitors the database performance and makes adjustments to optimize it

Who introduced the relational model?

E.F. Codd

What is the purpose of the ON clause in SQL joins?

Specifies the condition for the join between the two tables

Which component is responsible for executing instructions from the query processor?

Storage engine

The storage engine in MySQL is also known as:

Storage manager

Which of the following is NOT a characteristic of a database system?

Stores data in an unstructured format

What does SQL stand for?

Structured Query Language

What is the main purpose of the MySQL Monitor in the Enterprise Edition?

To collect and display system performance information