Data Modeling Exam
1. Which normal form addresses Eliminate Redundant Data
a.1NF
b.2NF
c.3NF
d.4NF
e.5NF
f.BCNF
2. Which normal form addresses Eliminate Columns Not Dependent on Key
a.1NF
b.2NF
c.3NF
d.4NF
e.5NF
f.BCNF
3. Which normal form addresses eliminating repeating groups
a.1NF
b.2NF
c.3NF
d.4NF
e.5NF
f.BCNF
4. The most common format used for data modeling is:
a. state-transition diagramming.
b. entity-relationship diagramming.
c. process modeling.
d. logic modeling.
e. a flowchart
5. A person, place, object, event, or concept in the user environment about which
the organization wishes to maintain data refers to a(n):
a. attribute.
b. data element.
c. relationship.
d. entity.
e. process.
6. A renewal is an example of a(n):
a. data element.
b. attribute.
c. entity.
d. relationship.
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e. action stub.
7. Which of the following is a true statement?
a. Data entities correspond to sources/sinks on a data flow diagram.
b. Relationships correspond to data flows on a data flow diagram.
c. A data entity will have many possible instances.
d. Verbs are used to name entity types.
e. An entity type is described many times in the data model.
8. An attribute (or combination of attributes) that uniquely identifies each instance
of an entity type defines:
a. data element occurrence.
b. trigger.
c. candidate key.
d. associative entity.
e. data marker.
9. When selecting an identifier, one should:
a. use intelligent keys.
b. use large composite keys instead of single-attribute surrogate keys.
c. choose a candidate key that will not change its value over the life of
each
instance of the entity type.
d. choose a candidate key such that for each instance of the entity, the attribute
is guaranteed to have valid values or is null.
e. choose a candidate key that allows for duplicate values.
10. If each employee can have more than one skill, then skill is referred to as a:
a. gerund.
b. multivalued attribute.
c. nonexclusive attribute.
d. repeating attribute.
e. data replica.
11. Which statements are correct about the TIMESTAMP WITH LOCAL TIME ZONE
datatype? (Choose two answers.)(Oracle)
a. Data is saved with a local time zone indicator.
b. Data is normalized to the database time zone when it is saved.
c. On retrieval, data is normalized to the retrieving client’s time
zone.
d. On retrieval, data is normalized to the time zone of the client that
entered it.
12. When do you introduce ASSOCIATE ENTITY in physical data model?
When There is M-M relation between two entities
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13. What are Subtypes and Supertypes?
User while creating the conceptual data model. Supertyping and subtyping are
techniques that data modelers use to better understand how data is structured and
to understand the metadata. Supertypes and subtypes are structures that are used
in the requirements-gathering stage of database development.
14. Put following in order
Database Script,
Schema,
Logical Data Model,
Physical Data Model,
Context flow diagram
1) Context flow diagram
2) Logical Data Model
3) Physical Data Model
4) Database Script
5) Schema
15. How to identify which is parent?
• 1 is parent
• Compulsory is parent (Country President)
• First come in is parent
16. What are methods of demoralization?
• merging multiple attributes
• merging multiple entities that are related
• merging non-related entities into single entity
17. List model components in ERwin
• subject area
• Display
• Other Objects are like entities, relations, attributes, business rules at logical
model level and tables, views, synonyms, sequences etc at physical model
level
18. What is Identifying Relation?
PK of parent entity is used as FK into child entity and FK also becomes part of PK
within child entity. So, In this case child entity will have composite PK.
19. What is purpose of Volumetrics feature in ERwin?
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20. How Logical and Physical Data Models are different?
• Logical model has to be without using technical terms from database or
operating system etc. This model includes only following four things
Entities
Relations
Attributes
Business Rules (Constraints / Validations)
• Physical Model is implementation (database) specific
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