WGU C175 or D426 DATA
MANAGEMENT FOUNDATIONS OA
EXAM 2023-2024 ACTUAL EXAM 2
Versions-with 100% verified solutions-2023
With 300 Q&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-
- Volat ility
- 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
Les avantages d'acheter des résumés chez Stuvia:
Qualité garantie par les avis des clients
Les clients de Stuvia ont évalués plus de 700 000 résumés. C'est comme ça que vous savez que vous achetez les meilleurs documents.
L’achat facile et rapide
Vous pouvez payer rapidement avec iDeal, carte de crédit ou Stuvia-crédit pour les résumés. Il n'y a pas d'adhésion nécessaire.
Focus sur l’essentiel
Vos camarades écrivent eux-mêmes les notes d’étude, c’est pourquoi les documents sont toujours fiables et à jour. Cela garantit que vous arrivez rapidement au coeur du matériel.
Foire aux questions
Qu'est-ce que j'obtiens en achetant ce document ?
Vous obtenez un PDF, disponible immédiatement après votre achat. Le document acheté est accessible à tout moment, n'importe où et indéfiniment via votre profil.
Garantie de remboursement : comment ça marche ?
Notre garantie de satisfaction garantit que vous trouverez toujours un document d'étude qui vous convient. Vous remplissez un formulaire et notre équipe du service client s'occupe du reste.
Auprès de qui est-ce que j'achète ce résumé ?
Stuvia est une place de marché. Alors, vous n'achetez donc pas ce document chez nous, mais auprès du vendeur Studiespro. Stuvia facilite les paiements au vendeur.
Est-ce que j'aurai un abonnement?
Non, vous n'achetez ce résumé que pour €26,72. Vous n'êtes lié à rien après votre achat.
