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WGU C175| D426 DATA MANAGEMENT
REAL EXAM QUESTIONS WITH VERIFIED
SOLUTIONS LATEST MODIFIED EXAM
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.
Data ---- ANSWER----Facts that are collected and stored in a database system.
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Determining characteristic of unstructured data ---- ANSWER----It does not
follow a data model.
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.
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Index creation on a database column ---- ANSWER----To optimize data
retrievals.
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.
Flat files ---- ANSWER----They contain no internal hierarchical organization.
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 nonkey
columns depend on the WHOLE primary key - Must be in 1NF - Non-key
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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.
WGU C175| D426 DATA MANAGEMENT
REAL EXAM QUESTIONS WITH VERIFIED
SOLUTIONS LATEST MODIFIED EXAM
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.
Data ---- ANSWER----Facts that are collected and stored in a database system.
, Page 2 of 64
Determining characteristic of unstructured data ---- ANSWER----It does not
follow a data model.
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.
, Page 3 of 64
Index creation on a database column ---- ANSWER----To optimize data
retrievals.
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.
Flat files ---- ANSWER----They contain no internal hierarchical organization.
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 nonkey
columns depend on the WHOLE primary key - Must be in 1NF - Non-key
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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.
