CS6400 – EXAM 3 NEWEST 2026 ACTUAL EXAM
QUESTIONS AND CORRECT DETAILED
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Logical (or conceptual) level - ✔✔✔ Correct Answer > how users
interpret the relation schemas and the meaning of their
attributes
Implementation (or physical storage) level - ✔✔✔ Correct Answer >
how the tuples in a base relation are stored and updated
Bottom-up design methodology - ✔✔✔ Correct Answer > (also called
design by synthesis) considers the basic relationships among
individual attributes as the starting point and uses those to
construct relation schemas
Top-down design methodology - ✔✔✔ Correct Answer > (also called
design by analysis) starts with a number of groupings of
attributes into relations that exist together naturally
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Measures to determine the quality of relation schema design -
✔✔✔ Correct Answer > ■ Making sure that the semantics of the
attributes is clear in the schema
■ Reducing the redundant information in tuples
■ Reducing the NULL values in tuples
■ Disallowing the possibility of generating spurious tuples
Semantics of a relation - ✔✔✔ Correct Answer > refers to its meaning
resulting from the interpretation of attribute values in a tuple
Update anomalies - ✔✔✔ Correct Answer > can be classified into
insertion anomalies, deletion anomalies, and modification
anomalies
Insertion Anomalies - ✔✔✔ Correct Answer > occur when users
attempt to store an attribute value in the system but they
cannot because the value of another unnecessary but required
attribute is not known
Deletion Anomalies - ✔✔✔ Correct Answer > occur when a value
for one attribute that users wish to keep is unexpectedly
removed when a value for another attribute is deleted
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Modification Anomalies - ✔✔✔ Correct Answer > occur when
changes to multiple instances of an entity (rows of a table) are
needed to effect an update to a single value of an attribute
Spurious tuples - ✔✔✔ Correct Answer > Tuples generated by
joining two relations on attributes that are not keys or foreign
keys on these relations.
Waste of storage space - ✔✔✔ Correct Answer > due to nulls and
the difficulty of performing selections, aggregation operations,
and joins due to NULL values
A functional dependency (A->B) - ✔✔✔ Correct Answer > occurs
when the attribute A uniquely determines B. A = left-hand
side, B=right-hand-side.
-is a property of the semantics or meaning of the attributes.
FD or f.d. - ✔✔✔ Correct Answer > abbreviation for functional
dependency
Candidate Key - ✔✔✔ Correct Answer > An attribute, or combination of
attributes, that uniquely identifies a row in a relation.
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Legal relation states (or legal extensions) of R - ✔✔✔ Correct Answer
> Relation extensions r(R) that satisfy the functional dependency
constraints
FD cannot be inferred automatically - ✔✔✔ Correct Answer > must be
defined explicitly by someone who knows the semantics of the
attributes of R.
Diagrammatic notation - ✔✔✔ Correct Answer > isplaying fds: Each FD
is displayed as a horizontal
Normalization of Data - ✔✔✔ Correct Answer > a process of
analyzing the given relation schemas based on their fds and
primary keys to achieve the desirable properties of (1)
minimizing redundancy and (2) minimizing the insertion,
deletion, and update anomalies
Boyce-Codd Normal Form (BCNF) - ✔✔✔ Correct Answer > A
special type of third normal form (3NF) in which every
determinant is a candidate key. A table in BCNF must be in
3NF.
Normal form test - ✔✔✔ Correct Answer > is decomposed into
smaller relation schemas that contain a subset of the attributes
and meet the test that was otherwise not met by the original
relation.