WGU C175/D426 DATA MANAGEMENT EXAM REVIEW
QUESTIONS & ANSWERS | LATEST ALREADY GRADED A+
UPDATE 2026|2027
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.
Integrate in ETL - CORRECT ANSWER ✔✔ - Data is put into a uniform structure;
Data converted to uniform structure.
Restructure in ETL - CORRECT ANSWER ✔✔ - Data is structured in a design that is
optimal for analysis.
1
,Load in ETL - CORRECT ANSWER ✔✔ - Data is loaded to the data warehouse.
Issue focused on 'Load' component of ETL - CORRECT ANSWER ✔✔ - Monitor
refreshing volume and frequency.
Step in ETL Process where raw data is aggregated - CORRECT ANSWER ✔✔ -
Transformation steps.
Data mining activities - CORRECT ANSWER ✔✔ - 1. Clustering & Segmentation 2.
Classification 3. Estimation 4. Prediction 5. Affinity Grouping 6. Description.
Clustering & Segmentation - CORRECT ANSWER ✔✔ - Taking large entity and
dividing into smaller groups of entities. Useful when unsure of what looking for.
Classification (Data Mining) - CORRECT ANSWER ✔✔ - Organizing data into
predefined classes.
Estimation (Data Mining) - CORRECT ANSWER ✔✔ - Assigning a numeric value to
an object.
Prediction (Data Mining) - CORRECT ANSWER ✔✔ - Classifying objects according
to an expected future behavior.
Affinity Grouping - CORRECT ANSWER ✔✔ - Evaluating relationships between
data elements that demonstrate some kind of affinity between objects.
2
,Entity types - CORRECT ANSWER ✔✔ - The uniquely identifiable element about
which data can be categorized in an entity-relationship diagram.
Referential integrity rules by modern relational database management systems -
CORRECT ANSWER ✔✔ - Insert, Update, Delete.
DISTINCT clause - CORRECT ANSWER ✔✔ - Returns only unique or 'distinct'
values; Filters Data Results.
ORDER BY clause - CORRECT ANSWER ✔✔ - Modifies presentation of data results.
Heap file - CORRECT ANSWER ✔✔ - A file where records can be placed anywhere
in the memory.
Hash file - CORRECT ANSWER ✔✔ - A file that uses Hash function computation on
some fields of the records, and the result of that computation determines where
the record is stored.
Major Joins - CORRECT ANSWER ✔✔ - - LEFT JOIN - RIGHT JOIN - INNER JOIN -
FULL JOIN.
Joins - CORRECT ANSWER ✔✔ - Joins usually compare the foreign key of one table
to the primary key of another table (but can join any columns) - joining together
data from two tables into one table.
3
, LEFT JOIN - CORRECT ANSWER ✔✔ - Selects all the rows from the left table, and
only matching rows from the right table.
RIGHT JOIN - CORRECT ANSWER ✔✔ - Selects all the rows from the right table,
and only matching rows from the left table.
OUTER JOIN - CORRECT ANSWER ✔✔ - Any join that selects unmatched rows;
LEFT, RIGHT, or FULL JOINS.
INNER JOIN - CORRECT ANSWER ✔✔ - Joins together only rows that match from
both tables - contains no unmatched rows.
FULL JOIN - CORRECT ANSWER ✔✔ - Fully joins two tables together, even
unmatched rows - places a NULL in any cell that does not match the other table.
Signed vs. Unsigned data - CORRECT ANSWER ✔✔ - - SIGNED: a number that may
be negative - UNSIGNED: a number that can NOT be negative.
CHAR vs. VARCHAR - CORRECT ANSWER ✔✔ - - CHAR: Fixed number of characters
- VARCHAR: Variable length of characters.
Record - CORRECT ANSWER ✔✔ - A set of one or more fields.
VARCHAR - CORRECT ANSWER ✔✔ - Variable length of characters
CHAR - CORRECT ANSWER ✔✔ - Fixed number of characters
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QUESTIONS & ANSWERS | LATEST ALREADY GRADED A+
UPDATE 2026|2027
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.
Integrate in ETL - CORRECT ANSWER ✔✔ - Data is put into a uniform structure;
Data converted to uniform structure.
Restructure in ETL - CORRECT ANSWER ✔✔ - Data is structured in a design that is
optimal for analysis.
1
,Load in ETL - CORRECT ANSWER ✔✔ - Data is loaded to the data warehouse.
Issue focused on 'Load' component of ETL - CORRECT ANSWER ✔✔ - Monitor
refreshing volume and frequency.
Step in ETL Process where raw data is aggregated - CORRECT ANSWER ✔✔ -
Transformation steps.
Data mining activities - CORRECT ANSWER ✔✔ - 1. Clustering & Segmentation 2.
Classification 3. Estimation 4. Prediction 5. Affinity Grouping 6. Description.
Clustering & Segmentation - CORRECT ANSWER ✔✔ - Taking large entity and
dividing into smaller groups of entities. Useful when unsure of what looking for.
Classification (Data Mining) - CORRECT ANSWER ✔✔ - Organizing data into
predefined classes.
Estimation (Data Mining) - CORRECT ANSWER ✔✔ - Assigning a numeric value to
an object.
Prediction (Data Mining) - CORRECT ANSWER ✔✔ - Classifying objects according
to an expected future behavior.
Affinity Grouping - CORRECT ANSWER ✔✔ - Evaluating relationships between
data elements that demonstrate some kind of affinity between objects.
2
,Entity types - CORRECT ANSWER ✔✔ - The uniquely identifiable element about
which data can be categorized in an entity-relationship diagram.
Referential integrity rules by modern relational database management systems -
CORRECT ANSWER ✔✔ - Insert, Update, Delete.
DISTINCT clause - CORRECT ANSWER ✔✔ - Returns only unique or 'distinct'
values; Filters Data Results.
ORDER BY clause - CORRECT ANSWER ✔✔ - Modifies presentation of data results.
Heap file - CORRECT ANSWER ✔✔ - A file where records can be placed anywhere
in the memory.
Hash file - CORRECT ANSWER ✔✔ - A file that uses Hash function computation on
some fields of the records, and the result of that computation determines where
the record is stored.
Major Joins - CORRECT ANSWER ✔✔ - - LEFT JOIN - RIGHT JOIN - INNER JOIN -
FULL JOIN.
Joins - CORRECT ANSWER ✔✔ - Joins usually compare the foreign key of one table
to the primary key of another table (but can join any columns) - joining together
data from two tables into one table.
3
, LEFT JOIN - CORRECT ANSWER ✔✔ - Selects all the rows from the left table, and
only matching rows from the right table.
RIGHT JOIN - CORRECT ANSWER ✔✔ - Selects all the rows from the right table,
and only matching rows from the left table.
OUTER JOIN - CORRECT ANSWER ✔✔ - Any join that selects unmatched rows;
LEFT, RIGHT, or FULL JOINS.
INNER JOIN - CORRECT ANSWER ✔✔ - Joins together only rows that match from
both tables - contains no unmatched rows.
FULL JOIN - CORRECT ANSWER ✔✔ - Fully joins two tables together, even
unmatched rows - places a NULL in any cell that does not match the other table.
Signed vs. Unsigned data - CORRECT ANSWER ✔✔ - - SIGNED: a number that may
be negative - UNSIGNED: a number that can NOT be negative.
CHAR vs. VARCHAR - CORRECT ANSWER ✔✔ - - CHAR: Fixed number of characters
- VARCHAR: Variable length of characters.
Record - CORRECT ANSWER ✔✔ - A set of one or more fields.
VARCHAR - CORRECT ANSWER ✔✔ - Variable length of characters
CHAR - CORRECT ANSWER ✔✔ - Fixed number of characters
4
