Practice — DM5-013–024
DM5-013 — Relationships · Foundational · recall
What does relationship cardinality describe?
A. How many occurrences of one entity may or must be associated with an occurrence of another, including optionality.
B. The number of attributes in an entity.
C. The number of entities participating in a relationship.
D. The number of candidate keys in a model.
DM5-014 — Relationships · Standard · recall
What does relationship arity describe?
A. Whether participation is optional or mandatory.
B. The number of entity types participating in the relationship.
C. How many rows exist in a physical table.
D. How many attributes compose a key.
DM5-015 — Relationships · Standard · apply
An Employee entity has a 'reports to' relationship back to Employee. What relationship type is this?
A. Binary relationship
B. Ternary relationship
C. Unary (recursive) relationship
D. Non-identifying relationship
DM5-016 — Relationships · Standard · apply
A business rule can be stated only by relating Supplier, Product, and Location simultaneously. Which arity best fits?
A. Unary relationship
B. Binary relationship
C. Recursive relationship
D. Ternary relationship
DM5-017 — Relationships · Standard · understand
In a relational model, what does a foreign key represent?
A. A migrated key from a related parent entity used to represent the relationship.
B. A random value used only for encryption.
C. Any attribute that has a text data type.
D. The only key allowed in an entity.
DM5-018 — Relationships · Difficult · distinguish
Which clue indicates an identifying relationship?
A. The parent key migrates only as a non-key foreign key.
B. The parent's primary key migrates into the child's primary key.
C. The entities share no keys at all.
D. The child uses only a surrogate key and no parent reference.
DM5-019 — Relationships · Difficult · distinguish
Which clue indicates a non-identifying relationship?
A. The parent's key becomes part of the child's primary key.
B. The relationship has three entity types.
C. The parent's primary key migrates to the child as a foreign key but is not part of the child's primary key.
D. The relationship is optional.
DM5-020 — Components · Difficult · distinguish
According to Chapter 5, when is an entity dependent?
A. It has more than one non-key attribute.
B. It participates in any relationship.
C. It has a surrogate key.
D. Its primary key contains at least one attribute contributed from another entity.
DM5-021 — Keys · Foundational · recall
What distinguishes a composite key from a simple key?
A. A composite key contains two or more attributes; a simple key contains one.
B. Composite keys have business meaning while simple keys never do.
C. Composite keys are always surrogate keys.
D. Simple keys are always foreign keys.
DM5-022 — Keys · Difficult · distinguish
What makes a compound key more specific than a composite key in Chapter 5?
A. A compound key contains exactly one attribute.
B. A compound key is composite and each component is also a foreign key.
C. A compound key is always system-generated.
D. A compound key can never serve as a primary key.
DM5-023 — Keys · Standard · recall
Which statement best describes a surrogate key?
A. A business-recognized identifier used for retrieval.
B. Every candidate key not selected as primary.
C. A system-generated identifier with no business meaning or intelligence, generally hidden from users.
D. A key made only from foreign keys.
DM5-024 — Keys · Difficult · distinguish
Which statement correctly distinguishes a super key from a candidate key?
A. A candidate key must be system-generated; a super key must be business-defined.
B. A super key is always the chosen primary key.
C. A candidate key can contain duplicate values.
D. A super key is any unique attribute set; a candidate key is a minimal unique set.