WGU C777 OBJECTIVE ASSESSMENT 2 LATEST VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)

WGU C777 OBJECTIVE ASSESSMENT 2 LATEST VERSIONS
(VERSION A AND B) COMPLETE 400 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)



Question 1
Which of the following is a primary purpose of a database management
system (DBMS)?
A) To create physical hardware infrastructure.
B) To manage and organize data efficiently.
C) To design user interfaces for applications.
D) To execute operating system commands.
E) To process raw, unstructured text documents.
Correct Answer: B) To manage and organize data efficiently.
Rationale: A DBMS is software designed to create, maintain, and
interact with a database, primarily for the efficient management and
organization of data, ensuring its integrity and security.

Question 2
In a relational database, what is a "tuple" commonly referred to as?
A) A column
B) A field
C) A table
D) A row (record)
E) An index
Correct Answer: D) A row (record)
Rationale: In relational database terminology, a tuple refers to a
single row in a table, which represents a single record of
information.

Question 3
Which SQL command is used to retrieve data from a database?
A) UPDATE
B) INSERT
C) DELETE
D) SELECT
E) CREATE
Correct Answer: D) SELECT
Rationale: The SELECT statement is the fundamental command in SQL
for querying and retrieving data from one or more tables in a
database.

,Question 4
What is a "Primary Key" in a relational database?
A) A column that contains unique values for each row and can contain NULLs.
B) A column that uniquely identifies each row in a table.
C) A column that refers to the primary key of another table.
D) A column used for sorting data in a table.
E) A column that stores encrypted data.
Correct Answer: B) A column that uniquely identifies each row in a
table.
Rationale: A Primary Key is a column or a set of columns in a table
that uniquely identifies each row in that table. It cannot contain
NULL values and must have unique values.

Question 5
Which of the following SQL commands is part of Data Definition Language
(DDL)?
A) INSERT
B) UPDATE
C) DELETE
D) CREATE
E) SELECT
Correct Answer: D) CREATE
Rationale: DDL (Data Definition Language) commands are used to
define, modify, and drop database objects like tables, views, and
indexes. CREATE is a DDL command, while INSERT, UPDATE, DELETE,
and SELECT are DML (Data Manipulation Language) commands.

Question 6
What does the term "normalization" primarily aim to achieve in database
design?
A) To speed up data retrieval.
B) To reduce data redundancy and improve data integrity.
C) To increase the complexity of database queries.
D) To ensure all tables have the same number of columns.
E) To encrypt sensitive data.
Correct Answer: B) To reduce data redundancy and improve data
integrity.
Rationale: Normalization is a process of organizing the columns and
tables of a relational database to minimize data redundancy and
improve data integrity. It aims to eliminate anomalous behavior
during data updates, insertions, and deletions.

,Question 7
A "Foreign Key" is used to establish a link between:
A) Two columns within the same table.
B) A column in one table and the primary key of another table.
C) Two different databases.
D) A table and a view.
E) A user and their permissions.
Correct Answer: B) A column in one table and the primary key of
another table.
Rationale: A Foreign Key is a field (or collection of fields) in one table
that uniquely identifies a row of another table. It establishes and
enforces a link between the data in two tables, ensuring referential
integrity.

Question 8
Which of the following clauses is used with aggregate functions to filter
groups based on a specified condition?
A) WHERE
B) ORDER BY
C) HAVING
D) GROUP BY
E) LIMIT
Correct Answer: C) HAVING
Rationale: The HAVING clause is used with the GROUP BY clause to
filter the groups created by the GROUP BY clause based on a
specified condition. The WHERE clause filters individual
rows before grouping.

Question 9
The ACID properties are crucial for ensuring the reliability of database
transactions. What does the 'A' in ACID stand for?
A) Availability
B) Atomicity
C) Accessibility
D) Authenticity
E) Agility
Correct Answer: B) Atomicity
Rationale: The ACID properties stand for Atomicity, Consistency,
Isolation, and Durability. Atomicity means that a transaction is
treated as a single, indivisible unit of work; either all of its
operations are completed, or none are.

, Question 10
In an Entity-Relationship Diagram (ERD), what symbol typically represents an
entity?
A) Diamond
B) Oval
C) Rectangle
D) Triangle
E) Circle
Correct Answer: C) Rectangle
Rationale: In an ERD, entities (which represent real-world objects or
concepts) are typically represented by rectangles.

Question 11
Which SQL command is used to modify existing records in a database table?
A) INSERT
B) UPDATE
C) DELETE
D) ALTER
E) MERGE
Correct Answer: B) UPDATE
Rationale: The UPDATE statement is a DML (Data Manipulation
Language) command used to change the values of existing records
(rows) in a table.

Question 12
What is the purpose of an "index" in a database?
A) To encrypt data for security.
B) To enforce referential integrity.
C) To speed up data retrieval operations.
D) To prevent data duplication.
E) To store metadata about the database.
Correct Answer: C) To speed up data retrieval operations.
Rationale: An index is a special lookup table that the database search
engine can use to speed up data retrieval. It works much like an
index in a book, allowing direct access to specific data without
scanning the entire table.

Question 13
Which type of relationship exists when one record in Table A can relate to
zero, one, or many records in Table B, and one record in Table B can relate to
zero, one, or many records in Table A?