WGU C175-D426 DATA MANAGEMENT FOUNDATIONS OA Exam 2025
UPDATE/PRACTICE QUESTIONS AND CORRECT VERIFIED
ANSWERS(complete solutions) ASSURED SUCCESS/GRADED A+!!!
Data retrieval before database management systems - CORRECT ANSWER-
Sequentially from simple files.
Primary Key - CORRECT ANSWER-An attribute or group of attributes that
uniquely identify a tuple in a relation.
Foreign Key matching - CORRECT 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 - CORRECT ANSWER-What uniquely identifies each entity in a
collection of entities but is not the primary key.
Candidate Key - CORRECT ANSWER-A set of columns in a table that can uniquely
identify any record in that table without referring to other data.
Database indexing - CORRECT ANSWER-The original data is copied to the index.
,Indexes in physical database design - CORRECT ANSWER-To retrieve data
DIRECTLY using a pointer.
Index creation on a database column - CORRECT ANSWER-To optimize data
retrievals.
Functional Dependency - CORRECT ANSWER-Each value of a column relates to
at MOST one value of another column.
Rules/Appearance of First Normal Form - CORRECT 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 - CORRECT 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 - CORRECT ANSWER-- All non-key
columns depend ONLY on the primary key - Tables are totally free of data
redundancy.
Modality - CORRECT 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.
,Referential Integrity - CORRECT ANSWER-Requires that ALL foreign key values
must either be fully NULL or match some primary key value.
Ways Referential Integrity can be violated - CORRECT 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 - CORRECT 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.
Important aspect of Referential Integrity - CORRECT ANSWER-Reference to data
in one relation is based on values in another relation.
Broad definition of data - CORRECT ANSWER-Raw facts captured on printed or
digital media.
Data - CORRECT ANSWER-Facts that are collected and stored in a database
system.
Determining characteristic of unstructured data - CORRECT ANSWER-It does not
follow a data model.
Flat files - CORRECT ANSWER-They contain no internal hierarchical organization.
, Differences between operational and analytical databases - CORRECT ANSWER-
- Volatility - Detail - Scope - History.
Volatility - CORRECT ANSWER-Database updates in real time. Operational Data
is Volatile. Analytical Data is NOT Volatile.
Detail in databases - CORRECT ANSWER-- A database that keeps record of
individual transactions; line items - Operational: Detailed - Analytical: Detailed.
Scope in databases - CORRECT ANSWER-- How far a database can reach -
Operational: incompatible - Analytical: Enterprise-Wide/Summary.
History in databases - CORRECT ANSWER-- Whether DB is current or tracks all
data - Operational: Current only - Analytical: Tracks trends.
Data warehouse refresh process - CORRECT ANSWER-1. Extraction 2. Cleanse 3.
Integrate 4. Restructure 5. Load.
Extraction in ETL - CORRECT ANSWER-Data extracted and put into staging area.
Cleanse in ETL - CORRECT ANSWER-Errors are eliminated from data; standard
abbreviations applied.
UPDATE/PRACTICE QUESTIONS AND CORRECT VERIFIED
ANSWERS(complete solutions) ASSURED SUCCESS/GRADED A+!!!
Data retrieval before database management systems - CORRECT ANSWER-
Sequentially from simple files.
Primary Key - CORRECT ANSWER-An attribute or group of attributes that
uniquely identify a tuple in a relation.
Foreign Key matching - CORRECT 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 - CORRECT ANSWER-What uniquely identifies each entity in a
collection of entities but is not the primary key.
Candidate Key - CORRECT ANSWER-A set of columns in a table that can uniquely
identify any record in that table without referring to other data.
Database indexing - CORRECT ANSWER-The original data is copied to the index.
,Indexes in physical database design - CORRECT ANSWER-To retrieve data
DIRECTLY using a pointer.
Index creation on a database column - CORRECT ANSWER-To optimize data
retrievals.
Functional Dependency - CORRECT ANSWER-Each value of a column relates to
at MOST one value of another column.
Rules/Appearance of First Normal Form - CORRECT 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 - CORRECT 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 - CORRECT ANSWER-- All non-key
columns depend ONLY on the primary key - Tables are totally free of data
redundancy.
Modality - CORRECT 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.
,Referential Integrity - CORRECT ANSWER-Requires that ALL foreign key values
must either be fully NULL or match some primary key value.
Ways Referential Integrity can be violated - CORRECT 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 - CORRECT 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.
Important aspect of Referential Integrity - CORRECT ANSWER-Reference to data
in one relation is based on values in another relation.
Broad definition of data - CORRECT ANSWER-Raw facts captured on printed or
digital media.
Data - CORRECT ANSWER-Facts that are collected and stored in a database
system.
Determining characteristic of unstructured data - CORRECT ANSWER-It does not
follow a data model.
Flat files - CORRECT ANSWER-They contain no internal hierarchical organization.
, Differences between operational and analytical databases - CORRECT ANSWER-
- Volatility - Detail - Scope - History.
Volatility - CORRECT ANSWER-Database updates in real time. Operational Data
is Volatile. Analytical Data is NOT Volatile.
Detail in databases - CORRECT ANSWER-- A database that keeps record of
individual transactions; line items - Operational: Detailed - Analytical: Detailed.
Scope in databases - CORRECT ANSWER-- How far a database can reach -
Operational: incompatible - Analytical: Enterprise-Wide/Summary.
History in databases - CORRECT ANSWER-- Whether DB is current or tracks all
data - Operational: Current only - Analytical: Tracks trends.
Data warehouse refresh process - CORRECT ANSWER-1. Extraction 2. Cleanse 3.
Integrate 4. Restructure 5. Load.
Extraction in ETL - CORRECT ANSWER-Data extracted and put into staging area.
Cleanse in ETL - CORRECT ANSWER-Errors are eliminated from data; standard
abbreviations applied.
