WGU C175/D426 DATA MANAGEMENT
FOUNDATIONS OA EXAM NEWEST 2026
ACTUAL EXAM 2 LATEST VERSIONS 300
QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES (100%
CORRECT AND VERIFIED
ANSWERS)|ALREADY GRADED A+
What does Modality refers to? How does it appear on ER diagram? - ANSWER-
Refers to the MINIMUM number of times an instance in one entity can be
associated with instance of another entity (minima). Appears as a 0 or 1 on the
relationship line, next to cardinality.
Define: Referential Integrity - ANSWER-Requires that ALL foreign key values must
either be fully NULL or match some primary key value.
4 Ways Referential Integrity can be violated - ANSWER-1. Primary key is updated 2.
Foreign key is updated 3. Row containing primary key is DELETED 4. Row
containing foreign key is INSERTED.
Actions to Correct Referential Integrity Violation - ANSWER-1. RESTRICT - rejects
an insert, update, or delete 2. SET NULL - sets invalid foreign keys to null 3. SET
,DEFAULT - sets invalid foreign keys to a default primary value 4. CASCADE -
propagates primary key changes to foreign keys.
What is an Important aspect of Referential Integrity - ANSWER-Reference to data
in one relation is based on values in another relation.
What is Broad definition of data - ANSWER-Raw facts captured on printed or
digital media.
What Data - ANSWER-Facts that are collected and stored in a database system.
Determining characteristic of unstructured data - ANSWER-It does not follow a
data model.
Flat files - ANSWER-They contain no internal hierarchical organization.
Data retrieval before database management systems - ANSWER-Sequentially from
simple files.
Primary Key - ANSWER-An attribute or group of attributes that uniquely identify a
tuple in a relation.
Foreign Key matching - ANSWER-A domain of values is necessary for a primary key
in one relation of a database to match with its corresponding foreign key in
another relation of the same database.
,Alternate Key - ANSWER-What uniquely identifies each entity in a collection of
entities but is not the primary key.
Candidate Key - ANSWER-A set of columns in a table that can uniquely identify any
record in that table without referring to other data.
Database indexing - ANSWER-The original data is copied to the index.
Indexes in physical database design - ANSWER-To retrieve data DIRECTLY using a
pointer.
Index creation on a database column - ANSWER-To optimize data retrievals.
Functional Dependency - ANSWER-Each value of a column relates to at MOST one
value of another column.
Rules/Appearance of First Normal Form - ANSWER-- All non-key columns depend
on primary key - Each table cell contains one value - A table with no duplicate
rows.
Rules/Appearance of Second Normal Form - ANSWER-- When all non-key columns
depend on the WHOLE primary key - Must be in 1NF - Non-key column can not
depend on just one part of a composite key - a single primary key is automatically
in 2NF.
, Rules/Appearance of Third Normal Form - ANSWER-- All non-key columns depend
ONLY on the primary key - Tables are totally free of data redundancy.
Differences between operational and analytical databases - ANSWER-- Volatility -
Detail - Scope - History.
Volatility - ANSWER-Database updates in real time. Operational Data is Volatile.
Analytical Data is NOT Volatile.
Detail in databases - ANSWER-- A database that keeps record of individual
transactions; line items - Operational: Detailed - Analytical: Detailed.
Scope in databases - ANSWER-- How far a database can reach - Operational:
incompatible - Analytical: Enterprise-Wide/Summary.
History in databases - ANSWER-- Whether DB is current or tracks all data -
Operational: Current only - Analytical: Tracks trends.
Data warehouse refresh process - ANSWER-1. Extraction 2. Cleanse 3. Integrate 4.
Restructure 5. Load.
Extraction in ETL - ANSWER-Data extracted and put into staging area.
Cleanse in ETL - ANSWER-Errors are eliminated from data; standard abbreviations
applied.
FOUNDATIONS OA EXAM NEWEST 2026
ACTUAL EXAM 2 LATEST VERSIONS 300
QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES (100%
CORRECT AND VERIFIED
ANSWERS)|ALREADY GRADED A+
What does Modality refers to? How does it appear on ER diagram? - ANSWER-
Refers to the MINIMUM number of times an instance in one entity can be
associated with instance of another entity (minima). Appears as a 0 or 1 on the
relationship line, next to cardinality.
Define: Referential Integrity - ANSWER-Requires that ALL foreign key values must
either be fully NULL or match some primary key value.
4 Ways Referential Integrity can be violated - ANSWER-1. Primary key is updated 2.
Foreign key is updated 3. Row containing primary key is DELETED 4. Row
containing foreign key is INSERTED.
Actions to Correct Referential Integrity Violation - ANSWER-1. RESTRICT - rejects
an insert, update, or delete 2. SET NULL - sets invalid foreign keys to null 3. SET
,DEFAULT - sets invalid foreign keys to a default primary value 4. CASCADE -
propagates primary key changes to foreign keys.
What is an Important aspect of Referential Integrity - ANSWER-Reference to data
in one relation is based on values in another relation.
What is Broad definition of data - ANSWER-Raw facts captured on printed or
digital media.
What Data - ANSWER-Facts that are collected and stored in a database system.
Determining characteristic of unstructured data - ANSWER-It does not follow a
data model.
Flat files - ANSWER-They contain no internal hierarchical organization.
Data retrieval before database management systems - ANSWER-Sequentially from
simple files.
Primary Key - ANSWER-An attribute or group of attributes that uniquely identify a
tuple in a relation.
Foreign Key matching - ANSWER-A domain of values is necessary for a primary key
in one relation of a database to match with its corresponding foreign key in
another relation of the same database.
,Alternate Key - ANSWER-What uniquely identifies each entity in a collection of
entities but is not the primary key.
Candidate Key - ANSWER-A set of columns in a table that can uniquely identify any
record in that table without referring to other data.
Database indexing - ANSWER-The original data is copied to the index.
Indexes in physical database design - ANSWER-To retrieve data DIRECTLY using a
pointer.
Index creation on a database column - ANSWER-To optimize data retrievals.
Functional Dependency - ANSWER-Each value of a column relates to at MOST one
value of another column.
Rules/Appearance of First Normal Form - ANSWER-- All non-key columns depend
on primary key - Each table cell contains one value - A table with no duplicate
rows.
Rules/Appearance of Second Normal Form - ANSWER-- When all non-key columns
depend on the WHOLE primary key - Must be in 1NF - Non-key column can not
depend on just one part of a composite key - a single primary key is automatically
in 2NF.
, Rules/Appearance of Third Normal Form - ANSWER-- All non-key columns depend
ONLY on the primary key - Tables are totally free of data redundancy.
Differences between operational and analytical databases - ANSWER-- Volatility -
Detail - Scope - History.
Volatility - ANSWER-Database updates in real time. Operational Data is Volatile.
Analytical Data is NOT Volatile.
Detail in databases - ANSWER-- A database that keeps record of individual
transactions; line items - Operational: Detailed - Analytical: Detailed.
Scope in databases - ANSWER-- How far a database can reach - Operational:
incompatible - Analytical: Enterprise-Wide/Summary.
History in databases - ANSWER-- Whether DB is current or tracks all data -
Operational: Current only - Analytical: Tracks trends.
Data warehouse refresh process - ANSWER-1. Extraction 2. Cleanse 3. Integrate 4.
Restructure 5. Load.
Extraction in ETL - ANSWER-Data extracted and put into staging area.
Cleanse in ETL - ANSWER-Errors are eliminated from data; standard abbreviations
applied.
