WGU D426 Q&A 2024/2025 QUESTION AND
CORRECT ANSWER
Query Processor - ANSWER>>Interprets queries. Compiles queries into low-level instructions for
the storage engine. Creates a plan to modify the database or retrieve data, and returns query
results to the application.
Query Optimization - ANSWER>>Ensures the most efficient instructions are executed on the
data by the query processor.
Storage Manager/Engine - ANSWER>>Translates query processor instructions into low-level file
system commands. Uses indexes to quickly locate data.
Transaction Manager - ANSWER>>Ensures proper execution of transactions. Prevents conflicts
between concurrent transactions and restores the database to a consistent state in case of
failure.
CRUD - ANSWER>>Create, Read, Update, Delete. Operations: Insert(create), Select(read),
Update, Delete.
Analysis/Conceptual Design - ANSWER>>Specifies database requirements without specific
database system considerations. Represents requirements as entities, relationships, and
attributes.
Logical Design - ANSWER>>Implements database requirements in a specific system. Converts
entities, relationships, and attributes into tables, keys, and columns. Also known as schema.
Physical Design - ANSWER>>Adds indexes and specifies table organization on storage media.
Affects query processing speed but not query results.
Data Independence - ANSWER>>Physical design does not affect query results.
API (Application Programming Interface) - ANSWER>>Library of procedures/classes linking a
programming language to a database. Simplifies SQL usage.
, MySQL Command-Line Client - ANSWER>>A text interface included in the MySQL Server
download.
Set - ANSWER>>An unordered collection of elements enclosed in braces {}.
Tuple - ANSWER>>An ordered collection of elements enclosed in parentheses ().
Business Rules - ANSWER>>Based on business policy and specific to a particular database.
Relational rules govern data in all relational databases.
DDL - ANSWER>>Data Definition Language (DDL) defines the structure of the database. Controls
tables. Includes CREATE, DROP, ALTER, TRUNCATE, RENAME.
DQL - ANSWER>>Data Query Language (DQL) retrieves data from the database. Uses SELECT
statement.
DML - ANSWER>>Data Manipulation Language (DML) manipulates data stored in a database.
Adds, modifies, and deletes data. Uses INSERT, UPDATE, DELETE statements.
DCL - ANSWER>>Data Control Language (DCL) controls database user access. Used to create
user accounts, manage permissions, and access.
DTL - ANSWER>>Data Transaction Language (DTL) manages database transactions. Can rollback
database changes.
UPDATE - ANSWER>>The UPDATE statement modifies existing rows in a table. It uses the SET
clause to specify the new column values.
DELETE Statement - ANSWER>>The DELETE statement removes existing rows from a table. It is
followed by the FROM keyword and the table name.
Primary Key - ANSWER>>A primary key is a column or group of columns used to uniquely
identify a row. It is typically the first column in a table. It is simple if it consists of a single
column.
Composite Primary Key - ANSWER>>A composite primary key is made up of multiple columns.
CORRECT ANSWER
Query Processor - ANSWER>>Interprets queries. Compiles queries into low-level instructions for
the storage engine. Creates a plan to modify the database or retrieve data, and returns query
results to the application.
Query Optimization - ANSWER>>Ensures the most efficient instructions are executed on the
data by the query processor.
Storage Manager/Engine - ANSWER>>Translates query processor instructions into low-level file
system commands. Uses indexes to quickly locate data.
Transaction Manager - ANSWER>>Ensures proper execution of transactions. Prevents conflicts
between concurrent transactions and restores the database to a consistent state in case of
failure.
CRUD - ANSWER>>Create, Read, Update, Delete. Operations: Insert(create), Select(read),
Update, Delete.
Analysis/Conceptual Design - ANSWER>>Specifies database requirements without specific
database system considerations. Represents requirements as entities, relationships, and
attributes.
Logical Design - ANSWER>>Implements database requirements in a specific system. Converts
entities, relationships, and attributes into tables, keys, and columns. Also known as schema.
Physical Design - ANSWER>>Adds indexes and specifies table organization on storage media.
Affects query processing speed but not query results.
Data Independence - ANSWER>>Physical design does not affect query results.
API (Application Programming Interface) - ANSWER>>Library of procedures/classes linking a
programming language to a database. Simplifies SQL usage.
, MySQL Command-Line Client - ANSWER>>A text interface included in the MySQL Server
download.
Set - ANSWER>>An unordered collection of elements enclosed in braces {}.
Tuple - ANSWER>>An ordered collection of elements enclosed in parentheses ().
Business Rules - ANSWER>>Based on business policy and specific to a particular database.
Relational rules govern data in all relational databases.
DDL - ANSWER>>Data Definition Language (DDL) defines the structure of the database. Controls
tables. Includes CREATE, DROP, ALTER, TRUNCATE, RENAME.
DQL - ANSWER>>Data Query Language (DQL) retrieves data from the database. Uses SELECT
statement.
DML - ANSWER>>Data Manipulation Language (DML) manipulates data stored in a database.
Adds, modifies, and deletes data. Uses INSERT, UPDATE, DELETE statements.
DCL - ANSWER>>Data Control Language (DCL) controls database user access. Used to create
user accounts, manage permissions, and access.
DTL - ANSWER>>Data Transaction Language (DTL) manages database transactions. Can rollback
database changes.
UPDATE - ANSWER>>The UPDATE statement modifies existing rows in a table. It uses the SET
clause to specify the new column values.
DELETE Statement - ANSWER>>The DELETE statement removes existing rows from a table. It is
followed by the FROM keyword and the table name.
Primary Key - ANSWER>>A primary key is a column or group of columns used to uniquely
identify a row. It is typically the first column in a table. It is simple if it consists of a single
column.
Composite Primary Key - ANSWER>>A composite primary key is made up of multiple columns.
