WGU C175/D426 DATA MANAGEMENT FOUNDATIONS OA
EXAM -with 100% verified solutions-2023-2024 CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
VERSION A
What does modality refer to? How does it appear on ER diagram? - 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
Define: Referential Integrity - ANSWER- Requires that ALL foreign key values
must either be fully NULL or match some primary key value
4 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
4 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
What is an important aspect to referential integrity? - ANSWER- reference to data
in one relation is based on values in another relation
,What is a broad definition of data? - ANSWER- Raw facts captured on printed or
digital media
What are data? - ANSWER- Facts that are collected and stored in a database
system
What is a determining characteristic of unstructured data? - ANSWER- It does not
follow a data model
What is true about flat files? - ANSWER- - They contain no internal hierarchical
organization
How were data retrieved before database management systems? - ANSWER-
Sequentially from simple files
What is an attribute or group of attributes that uniquely identify a tuple in a
relation? - ANSWER- Primary Key
What 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? - ANSWER-
A domain of values
What uniquely identifies each entity in a collection of entities but is not the
primary key? - ANSWER- Alternate Key
What is the term for a set of columns in a table that can uniquely identify any
record in that table without referring to other data? - ANSWER- Candidate Key
What happens to the original data in database indexing? - ANSWER- It is copied
to the index
Why are indexes created in a physical database design? - ANSWER- To retrieve
data DIRECTLY using a pointer
Why is an index created on a database column? - ANSWER- To optimize data
retrievals
Define: Functional Dependency - ANSWER- Each value of a column relates to at
MOST one value of another column
Dependence of one column on another
,What term is used to describe: a value of one particular attribute associated with a
specific single value of another attribute? - ANSWER- Functional Dependency
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
What are the 4 ways that operational and analytical databases differ? - ANSWER-
- Volatility
- Detail
- Scope
- History
Define: Volatility; How it applies to Operational? Analytical? - ANSWER- -
Database updates in real time
- Operational Data is Volatile
- Analytical Data is NOT Volatile
Define: Detail; How it applies to operational and analytical DB? - ANSWER- - A
database that keeps record of individual transactions; line items
- Operational: Detailed
- Analytical: Detailed
Define: Scope; How it applies to operational and analytical DB? - ANSWER- -
How far a database can reach
- Operational: incompatible
- Analytical: Enterprise-Wide/Summary
,
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller NURSING2EXAM. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for $17.99. You're not tied to anything after your purchase.
