Question : Which operation in the relational model may cause issues if foreign key constraints are involved?
Solution :
Correct Answer : Deletion
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Question : Which of the following key types is formed when multiple attributes together uniquely identify a tuple?
Solution :
Correct Answer : Composite Key
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Question : In a relational model, which property ensures that each cell contains only a single value?
Solution :
Correct Answer : Atomicity of attributes
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Question : Which of the following statements about a domain is correct?
Solution :
Correct Answer : It is the set of all possible values an attribute can take
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Question : Which of the following correctly defines the degree of a relation?
Solution :
Correct Answer : Number of attributes in a relation
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Question : Which of the following is a unary operation in relational algebra?
Solution :
Correct Answer : Selection
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Question : Which operation is best suited for queries involving “for all” conditions?
Solution :
Correct Answer : Division
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Question : For two relations R and S to be union compatible, which condition must hold?
Solution :
Correct Answer : Same degree and compatible domains
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Question : Which relational algebra operation is used to retrieve tuples that satisfy a given condition?
Solution :
Correct Answer : Selection (σ)
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Question : Which of the following operations is NOT necessarily commutative in relational algebra?
Solution :
Correct Answer : Set Difference (−)
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Question : Which of the following statements is TRUE regarding RIGHT OUTER JOIN?
Solution :
Correct Answer : It returns all tuples from the right table and matched from the left
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Question : What is the key characteristic of a NATURAL JOIN?
Solution :
Correct Answer : Matches tuples based on common attribute names automatically
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Question : Which join is based strictly on equality condition (=) between attributes?
Solution :
Correct Answer : Equi Join
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Question : In a LEFT OUTER JOIN, what happens to tuples in the left table with no matching tuple in the right table?
Solution :
Correct Answer : They appear with NULL values for right table attributes
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Question : Which join returns all tuples from both relations including unmatched tuples?
Solution :
Correct Answer : Full Outer Join
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Question : Which of the following best describes a domain constraint?
Solution :
Correct Answer : Ensures values in a column follow a defined data type or range
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Question : Which statement is TRUE regarding primary key vs unique key?
Solution :
Correct Answer : Unique key can allow NULL values, primary key cannot
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Question : Which of the following is NOT a valid category of integrity constraint in DBMS?
Solution :
Correct Answer : Functional constraint
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Question : Which constraint ensures that a value in one table must match a value in another table or be NULL?
Solution :
Correct Answer : Referential integrity constraint
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Question : Which of the following situations violates entity integrity constraint?
Solution :
Correct Answer : A primary key contains NULL values
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Question : Which of the following best describes Relational Calculus?
Solution :
Correct Answer : It specifies what data is required, not how to retrieve it
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Question : Which of the following queries expresses existential quantification correctly?
Solution :
Correct Answer : { t | ∃u (R(u) ∧ t.A = u.A) }
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Question : Which statement best distinguishes Domain Relational Calculus (DRC) from Tuple Relational Calculus (TRC)?
Solution :
Correct Answer : DRC uses domain variables, TRC uses tuple variables
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Question : In Tuple Relational Calculus (TRC), a variable is said to be bound when:
Solution :
Correct Answer : It is quantified using ∀ or ∃
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Question : Which of the following correctly represents a safe TRC expression?
Solution :
Correct Answer : { t | t ∈ R ∧ t.A > 5 }
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