WGU C175/D426 DATA MANAGEMENT FOUNDATIONS OA
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EXAM -with 100% verified solutions-2023-2024 CORRECT AND
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VERIFIED ANSWERS)|ALREADY GRADED A+
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VERSION A z
What does modality refer to? How does it appear on ER diagram? - ANSWER-
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Refers to the MINIMUM number of times an instance in one entity can be
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associated with instance of another entity (minima)
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Appears as a 0 or 1 on the relationship line, next to cardinality
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Define: Referential Integrity - ANSWER- Requires that ALL foreign key values
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must either be fully NULL or match some primary key value
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4 Ways Referential Integrity can be violated: - ANSWER- 1. Primary key is
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updated
2. Foreign key is updated z z z
3. Row containing primary key is DELETED
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4. Row containing foreign key is INSERTED
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4 Actions to Correct Referential Integrity Violation: - ANSWER- 1. RESTRICT
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- rejects an insert, update, or delete
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2. SET NULL - sets invalid foreign keys to null
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3. SET DEFAULT - sets invalid foreign keys to a default primary value
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4. CASCADE - propagates primary key changes to foreign keys z z z z z z z z
What is an important aspect to referential integrity? - ANSWER- reference to
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data in one relation is based on values in another relation
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,What is a broad definition of data? - ANSWER- Raw facts captured on printed
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or digital media
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What are data? - ANSWER- Facts that are collected and stored in a database
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system
What is a determining characteristic of unstructured data? - ANSWER- It does not
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follow a data model
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What is true about flat files? - ANSWER- - They contain no internal
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hierarchical organization z
How were data retrieved before database management systems? - ANSWER-
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Sequentially from simple files z z z
What is an attribute or group of attributes that uniquely identify a tuple in a
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relation? - ANSWER- Primary Key z z z z
What is necessary for a primary key in one relation of a database to match with
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its corresponding foreign key in another relation of the same database? -
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ANSWER- A domain of values z z z z
What uniquely identifies each entity in a collection of entities but is not the
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primary key? - ANSWER- Alternate Key
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What is the term for a set of columns in a table that can uniquely identify any
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record in that table without referring to other data? - ANSWER- Candidate Key
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What happens to the original data in database indexing? - ANSWER- It is
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copied to the index
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Why are indexes created in a physical database design? - ANSWER- To
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retrieve data DIRECTLY using a pointer
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Why is an index created on a database column? - ANSWER- To optimize data
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retrievals
Define: Functional Dependency - ANSWER- Each value of a column relates to
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at MOST one value of another column
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Dependence of one column on another z z z z z
,What term is used to describe: a value of one particular attribute associated
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with a specific single value of another attribute? - ANSWER- Functional
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Dependency
Rules/Appearance of First Normal Form - ANSWER- - All non-key columns z z z z z z z z z z z
depend on primary key z z z
- Each table cell contains one value
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- A table with no duplicate rows
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Rules/Appearance of Second Normal Form - ANSWER- - When all non-key z z z z z z z z z z z
columns depend on the WHOLE primary key
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- Must be in 1NF z z z
- Non-key column can not depend on just one part of a composite key - a
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single primary key is automatically in 2NF
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Rules/Appearance of Third Normal Form - ANSWER- - All non-key columns z z z z z z z z z z z
depend ONLY on the primary key
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- Tables are totally free of data redundancy
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What are the 4 ways that operational and analytical databases differ? - ANSWER-
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- Volatility
- Detail
- Scope
- History
Define: Volatility; How it applies to Operational? Analytical? - ANSWER- -
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Database updates in real time z z z z
- Operational Data is Volatile z z z
- Analytical Data is NOT Volatile z z z z
Define: Detail; How it applies to operational and analytical DB? - ANSWER- -
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A database that keeps record of individual transactions; line items
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- Operational: Detailed z
- Analytical: Detailed z
Define: Scope; How it applies to operational and analytical DB? - ANSWER- -
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How far a database can reach
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- Operational: incompatible z
- Analytical: Enterprise-Wide/Summary z
,
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EXAM -with 100% verified solutions-2023-2024 CORRECT AND
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VERIFIED ANSWERS)|ALREADY GRADED A+
z z z
VERSION A z
What does modality refer to? How does it appear on ER diagram? - ANSWER-
z z z z z z z z z z z z z z
Refers to the MINIMUM number of times an instance in one entity can be
z z z z z z z z z z z z z z
associated with instance of another entity (minima)
z z z z z z
Appears as a 0 or 1 on the relationship line, next to cardinality
z z z z z z z z z z z z
Define: Referential Integrity - ANSWER- Requires that ALL foreign key values
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must either be fully NULL or match some primary key value
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4 Ways Referential Integrity can be violated: - ANSWER- 1. Primary key is
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updated
2. Foreign key is updated z z z
3. Row containing primary key is DELETED
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4. Row containing foreign key is INSERTED
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4 Actions to Correct Referential Integrity Violation: - ANSWER- 1. RESTRICT
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- rejects an insert, update, or delete
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2. SET NULL - sets invalid foreign keys to null
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3. SET DEFAULT - sets invalid foreign keys to a default primary value
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4. CASCADE - propagates primary key changes to foreign keys z z z z z z z z
What is an important aspect to referential integrity? - ANSWER- reference to
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data in one relation is based on values in another relation
z z z z z z z z z z
,What is a broad definition of data? - ANSWER- Raw facts captured on printed
z z z z z z z z z z z z z z
or digital media
z z
What are data? - ANSWER- Facts that are collected and stored in a database
z z z z z z z z z z z z z z
system
What is a determining characteristic of unstructured data? - ANSWER- It does not
z z z z z z z z z z z z
follow a data model
z z z
What is true about flat files? - ANSWER- - They contain no internal
z z z z z z z z z z z z z
hierarchical organization z
How were data retrieved before database management systems? - ANSWER-
z z z z z z z z z z
Sequentially from simple files z z z
What is an attribute or group of attributes that uniquely identify a tuple in a
z z z z z z z z z z z z z z z
relation? - ANSWER- Primary Key z z z z
What is necessary for a primary key in one relation of a database to match with
z z z z z z z z z z z z z z z z
its corresponding foreign key in another relation of the same database? -
z z z z z z z z z z z z
ANSWER- A domain of values z z z z
What uniquely identifies each entity in a collection of entities but is not the
z z z z z z z z z z z z z z
primary key? - ANSWER- Alternate Key
z z z z z
What is the term for a set of columns in a table that can uniquely identify any
z z z z z z z z z z z z z z z z z
record in that table without referring to other data? - ANSWER- Candidate Key
z z z z z z z z z z z z
What happens to the original data in database indexing? - ANSWER- It is
z z z z z z z z z z z z z
copied to the index
z z z
Why are indexes created in a physical database design? - ANSWER- To
z z z z z z z z z z z z
retrieve data DIRECTLY using a pointer
z z z z z
Why is an index created on a database column? - ANSWER- To optimize data
z z z z z z z z z z z z z z
retrievals
Define: Functional Dependency - ANSWER- Each value of a column relates to
z z z z z z z z z z z z
at MOST one value of another column
z z z z z z
Dependence of one column on another z z z z z
,What term is used to describe: a value of one particular attribute associated
z z z z z z z z z z z z z
with a specific single value of another attribute? - ANSWER- Functional
z z z z z z z z z z z
Dependency
Rules/Appearance of First Normal Form - ANSWER- - All non-key columns z z z z z z z z z z z
depend on primary key z z z
- Each table cell contains one value
z z z z z
- A table with no duplicate rows
z z z z z
Rules/Appearance of Second Normal Form - ANSWER- - When all non-key z z z z z z z z z z z
columns depend on the WHOLE primary key
z z z z z z
- Must be in 1NF z z z
- Non-key column can not depend on just one part of a composite key - a
z z z z z z z z z z z z z z z
single primary key is automatically in 2NF
z z z z z z
Rules/Appearance of Third Normal Form - ANSWER- - All non-key columns z z z z z z z z z z z
depend ONLY on the primary key
z z z z z
- Tables are totally free of data redundancy
z z z z z z
What are the 4 ways that operational and analytical databases differ? - ANSWER-
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- Volatility
- Detail
- Scope
- History
Define: Volatility; How it applies to Operational? Analytical? - ANSWER- -
z z z z z z z z z z z
Database updates in real time z z z z
- Operational Data is Volatile z z z
- Analytical Data is NOT Volatile z z z z
Define: Detail; How it applies to operational and analytical DB? - ANSWER- -
z z z z z z z z z z z z z
A database that keeps record of individual transactions; line items
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- Operational: Detailed z
- Analytical: Detailed z
Define: Scope; How it applies to operational and analytical DB? - ANSWER- -
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How far a database can reach
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- Operational: incompatible z
- Analytical: Enterprise-Wide/Summary z
,
