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WGU C175/D426 Data Management Exam Review
2025 Complete Questions And Verified Answers/
Complete Solutions With Rationales |Get It 100%
Accurate!! Already graded A+
Modality - (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 - (ANSWER)Requires that ALL foreign key values must either
be fully NULL or match some primary key value.
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.
Important aspect of Referential Integrity - (ANSWER)Reference to data in one
relation is based on values in another relation.
Broad definition of data - (ANSWER)Raw facts captured on printed or digital
media.
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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.
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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.
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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.
Integrate in ETL - (ANSWER)Data is put into a uniform structure; Data converted
to uniform structure.
WGU C175/D426 Data Management Exam Review
2025 Complete Questions And Verified Answers/
Complete Solutions With Rationales |Get It 100%
Accurate!! Already graded A+
Modality - (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 - (ANSWER)Requires that ALL foreign key values must either
be fully NULL or match some primary key value.
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.
Important aspect of Referential Integrity - (ANSWER)Reference to data in one
relation is based on values in another relation.
Broad definition of data - (ANSWER)Raw facts captured on printed or digital
media.
,2|Page
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.
,3|Page
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.
, 4|Page
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.
Integrate in ETL - (ANSWER)Data is put into a uniform structure; Data converted
to uniform structure.
