Q.1 Which of the following relational algebra operations do not require the participating tables to be union-compatible?
(A) Union
(B) Intersection
(C) Difference
(D) Join
Ans: (D)
Q.2 Which of the following is not a property of transactions?
(A) Atomicity
(B) Concurrency
(C) Isolation
(D) Durability
Ans: (B)
Q.3 Relational Algebra does not have
(A) Selection operator.
(B) Projection operator.
(C) Aggregation operators.
(D) Division operator.
Ans: (C)
Q.4 Checkpoints are a part of
(A) Recovery measures.
(B) Security measures.
(C) Concurrency measures.
(D) Authorization measures.
Ans: (A)
Q.5 Tree structures are used to store data in
(A) Network model.
(B) Relational model.
(C) Hierarchical model.
(D) File based system.
Ans: (C)
Q.6 The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is
(A) Procedural DML.
(B) Non-Procedural DML.
(C) Procedural DDL.
(D) Non-Procedural DDL.
Ans: (B)
Q.7 Precedence graphs help to find a
(A) Serializable schedule.
(B) Recoverable schedule.
(C) Deadlock free schedule.
(D) Cascadeless schedule.
Ans: (A)
Q.8 The rule that a value of a foreign key must appear as a value of some specific table is called a
(A) Referential constraint.
(B) Index.
(C) Integrity constraint.
(D) Functional dependency.
Ans: (A) The rule that a value of a foreign key must appear as a value of some specific table is called a referential constraint. (Referential integrity constraint is concerned with foreign key)
Q.9 The clause in SQL that specifies that the query result should be sorted in ascending or descending order based on the values of one or more columns is
(A) View
(B) Order by
(C) Group by
(D) Having
Ans: (B) The clause in SQL that specifies that the query result should be sorted in ascending or descending order based on the values of one or more columns is ORDER BY. (ORDER BY clause is used to arrange the result of the SELECT statement)
Q.10 What is a disjoint less constraint?
(A) It requires that an entity belongs to no more than one level entity set.
(B) The same entity may belong to more than one level.
(C) The database must contain an unmatched foreign key value.
(D) An entity can be joined with another entity in the same level entity set.
Ans: (A) Disjoint less constraint requires that an entity belongs to no more than one level entity set. (Disjoint less constraint means that an entity can be a member of at most one of the subclasses of the specialization.)
Q.11 According to the levels of abstraction, the schema at the intermediate level is called
(A) Logical schema.
(B) Physical schema.
(C) Subschema.
(D) Super schema.
Ans: According to the levels of abstraction, the schema at the intermediate level is called conceptual schema. (Note: All the options given in the question are wrong.)
Q.12 It is an abstraction through which relationships are treated as higher level entities
(A) Generalization.
(B) Specialization.
(C) Aggregation.
(D) Inheritance.
Ans: (C ) It is an abstraction through which relationships are treated as higher level entities Aggregation. (In ER diagram, aggregation is used to represent a relationship as an entity set.)
Q.13 A relation is in ____________ if an attribute of a composite key is dependent on an attribute of other composite key.
(A) 2NF
(B) 3NF
(C) BCNF
(D) 1NF
Ans: (B) A relation is in 3 NF if an attribute of a composite key is dependent on an attribute of other composite key. (If an attribute of a composite key is dependent on an attribute of other composite key then the relation is not in BCNF, hence it has to be decomposed.)
Q.14 What is data integrity?
(A) It is the data contained in database that is non redundant.
(B) It is the data contained in database that is accurate and consistent.
(C) It is the data contained in database that is secured.
(D) It is the data contained in database that is shared.
Ans: (B) (Data integrity means that the data must be valid according to the given constraints. Therefore, the data is accurate and consistent.)
Q.15 What are the desirable properties of a decomposition
(A) Partition constraint.
(B) Dependency preservation.
(C) Redundancy.
(D) Security.
Ans: (B) What are the desirable properties of a decomposition – dependency preserving. (Lossless join and dependency preserving are the two goals of the decomposition.)
Q.16 In an E-R diagram double lines indicate
(A) Total participation.
(B) Multiple participation.
(C) Cardinality N.
(D) None of the above.
Ans: (A)
Q.17 The operation which is not considered a basic operation of relational algebra is
(A) Join.
(B) Selection.
(C) Union.
(D) Cross product.
Ans: (A)
Q.18 Fifth Normal form is concerned with
(A) Functional dependency.
(B) Multivalued dependency.
(C) Join dependency.
(D) Domain-key.
Ans: (C)
Q.19 Block-interleaved distributed parity is RAID level
(A) 2.
(B) 3
(C) 4.
(D) 5.
Ans: (D)
Q.20 Immediate database modification technique uses
(A) Both undo and redo.
(B) Undo but no redo.
(C) Redo but no undo.
(D) Neither undo nor redo.
Ans: (A)
Q.21 In SQL the statement select * from R, S is equivalent to
(A) Select * from R natural join S.
(B) Select * from R cross join S.
(C) Select * from R union join S.
(D) Select * from R inner join S.
Ans: (B)
Q.22 Which of the following is not a consequence of concurrent operations?
(A) Lost update problem.
(B) Update anomaly.
(C) Unrepeatable read.
(D) Dirty read.
Ans: (B)
Q.23 As per equivalence rules for query transformation, selection operation distributes over
(A) Union.
(B) Intersection.
(C) Set difference.
(D) All of the above.
Ans: (D)
Q.24 The metadata is created by the
(A) DML compiler
(B) DML pre-processor
(C) DDL interpreter
(D) Query interpreter
Ans: (C)
Q.25 When an E-R diagram is mapped to tables, the representation is redundant for
(A) weak entity sets
(B) weak relationship sets
(C) strong entity sets
(D) strong relationship sets
Ans: (B)
