Multiple Choice Questions (MCQs)
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1 SET concept is used in:- (A) Network Model
- (B) Hierarchical Model
- (C) Relational Model
- (D) None of these
2 Relational Algebra is
- (A) Data Definition Language
- (B) Meta Language
- (C) Procedural Query Language
- (D) None of the above
3 Key to represent the relationship between tables is called
- (A) Primary key
- (B) Secondary Key
- (C) Foreign Key
- (D) None of these
4 —– produces the relation that has attributes of R1 and R2
- (A) Cartesian product
- (B) Difference
- (C) Intersection
- (D) Product
5 The file organization that provides very fast access to any arbitrary record of a file is
- (A) Ordered file
- (B) Unordered file
- (C) Hashed file
- (D) B—tree
6 DBMS helps achieve
- (A) Data independence
- (B) Centralized control of data
- (C) Neither A or B
- (D) Both A and B
7 Which of the following are the properties of entities?
- (A) Groups
- (B) Table
- (C) Attributes
- (D) Switchboards
8 In a relation
- (A) Ordering of rows is immaterial
- (B) No two rows are identical
- (C) A and B both are true
- (D) None of these
9 Which of the following is correct?
- (A) A SQL query automatically eliminates duplicates
- (B) SQL permits attribute names to be repeated in the same relation
- (C) A SQL query will not work if there are no indexes on the relation
- (D) None of these
10 It is better to use files than a DBMS when there are
- (A) Stringent real-time requirements
- (B) Multiple users wish to access the data
- (C) Complex relationships among data
- (D) All of the above
11 The conceptual model is
- (A) Dependent on hardware
- (B) Dependent on software
- (C) Dependent on both hardware and software
- (D) Independent of both hardware and software
12 What is a relationship called when it is maintained between two entities?
- (A) Unary
- (B) Binary
- (C) Ternary
- (D) Quaternary
13 Which of the following operation is used if we are interested in only certain columns of a table?
- (A) PROJECTION
- (B) SELECTION
- (C) UNION
- (D) JOIN
14 Which of the following is a valid SQL type?
- (A) CHARACTER
- (B) NUMERIC
- (C) FLOAT
- (D) All of the above
15 The RDBMS terminology for a row is
- (A) Tuple
- (B) Relation
- (C) Attribute
- (D) Degree
16 Which of the following operations need the participating relations to be union compatible?
- (A) UNION
- (B) INTERSECTION
- (C) DIFFERENCE
- (D) All of the above
17 The full form of DDL is
- (A) A Dynamic Data Language
- (B) Detailed Data Language
- (C) Data Definition Language
- (D) Data Derivation Language
18 Which of the following is an advantage of view?
- (A) Data security
- (B) Derived columns
- (C) Hiding of complex queries
- (D) All of the above
19 Which of the following is a legal expression in SQL?
- (A) SELECT NULL FROM EMPLOYEE;
- (B) SELECT NAME FROM EMPLOYEE;
- (C) SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL;
- (D) None of the above
20 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
21 Which of the following is not a property of transactions?
- (A) Atomicity
- (B) Concurrency
- (C) Isolation
- (D) Durability
22 Relational Algebra does not have
- (A) Selection operator
- (B) Projection operator
- (C) Aggregation operators
- (D) Division operator
23 Checkpoints are a part of
- (A) Recovery measures
- (B) Security measures
- (C) Concurrency measures
- (D) Authorization measures
24 Tree structures are used to store data in
- (A) Network model
- (B) Relational model
- (C) Hierarchical model
- (D) File based system
25 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
26 Precedence graphs help to find a
- (A) Serializable schedule
- (B) Recoverable schedule
- (C) Deadlock free schedule
- (D) Cascadeless schedule
27 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
28 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
29 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
30 According to the levels of abstraction, the schema at the intermediate level is called
- (A) Logical schema
- (B) Physical schema
- (C) Super schema
- (D) None of the above
31 It is an abstraction through which relationships are treated as higher level entities
- (A) Generalization
- (B) Specialization
- (C) Aggregation
- (D) Inheritance
32 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
33 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
34 What are the desirable properties of decomposition?
- (A) Partition constraint
- (B) Dependency preservation
- (C) Redundancy
- (D) Security
35 In an E-R diagram double lines indicate
- (A) Total participation
- (B) Multiple participation
- (C) Cardinality N
- (D) None of the above
36 The operation which is not considered a basic operation of relational algebra is
- (A) Join
- (B) Selection
- (C) Union
- (D) Cross product
37 Fifth Normal form is concerned with
- (A) Functional dependency
- (B) Multivalued dependency
- (C) Join dependency
- (D) Domain-key
38 Block-interleaved distributed parity is RAID level
- (A) 2
- (B) 3
- (C) 4
- (D) 5
39 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
40 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
41 Which of the following is not a consequence of concurrent operations?
- (A) Lost update problem
- (B) Update anomaly
- (C) Unrepeatable read
- (D) Dirty read
42 As per equivalence rules for query transformation, selection operation distributes over
- (A) Union
- (B) Intersection
- (C) Set difference
- (D) All of the above
43 The metadata is created by the
- (A) DML compiler
- (B) DML pre-processor
- (C) DDL interpreter
- (D) Query interpreter
44 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
45 When R∩S = f, then the cost of computing R >< S is
- (A) The same as R × S
- (B) Greater the R × S
- (C) Less than R × S
- (D) Cannot say anything
46 In SQL the word ‘natural’ can be used with
- (A) Inner join
- (B) Full outer join
- (C) Right outer join
- (D) All of the above
47 The default level of consistency in SQL is
- (A) Repeatable read
- (B) Read committed
- (C) Read uncommitted
- (D) Serializable
48 If a transaction T has obtained an exclusive lock on item Q, then T can
- (A) Read Q
- (B) Write Q
- (C) Both read and write Q
- (D) Write Q but not read Q
49 Shadow paging has
- (A) No redo
- (B) No undo
- (C) Redo but no undo
- (D) Neither redo nor undo
50 If the closure of an attribute set is the entire relation then the attribute set is a
- (A) Super key
- (B) Candidate key
- (C) Primary key
- (D) Not a key
51 DROP is a ______________ statement in SQL
- (A) Query
- (B) Embedded SQL
- (C) DDL
- (D) DCL
52 If two relations R and S are joined, then the non matching tuples of both R and S are ignored in
- (A) Left outer join
- (B) Right outer join
- (C) Full outer join
- (D) Inner join
53 The keyword to eliminate duplicate rows from the query result in SQL is
- (A) DISTINCT
- (B) NO DUPLICATE
- (C) UNIQUE
- (D) None of the above
54 In 2NF
- (A) No functional dependencies (FDs) exist
- (B) No multivalued dependencies (MVDs) exist
- (C) No partial FDs exist
- (D) No partial MVDs exist
55 Which one is correct statement? Logical data independence provides following without changing application programs: (i) Changes in access methods. (ii) Adding new entities in database (iii) Splitting an existing record into two or more records (iv) Changing storage medium
- (A) (i) and (ii)
- (B) (iv) only,
- (C) (i) and (iv)
- (D) ii and iii
56 In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect?
- (A) Operationally, if Y is deleted, so is X
- (B) Existence is dependent on Y
- (C) Operationally, if X is deleted, so is Y
- (D) Operationally, if X is deleted, & remains the same
57 Which of the following aggregate functions does not ignore nulls in its results?
- (A) COUNT
- (B) COUNT (*)
- (C) MAX
- (D) MIN
58 R (A, B, C, D) is a relation. Which of the following does not have a lossless join dependency preserving BCNF decomposition
- (A) A->B, B->CD
- (B) A->B, B->C, C->D
- (C) AB->C, C->AD
- (D) A->BCD
59 Consider the join of relation R with a relation S. If R has m tuples and S has n tuples, then the maximum and minimum size of the join respectively are
- (A) m+n and 0
- (B) m+n and |m-n|
- (C) mn and 0
- (D) mn and m+n
60 Maximum height of a B+ tree of order m with n key values is
- (A) Logm(n)
- (B) (m+n)/2
- (C) Logm/2m+n
- (D) None of these
61 Which one is true statement?
- (A) With finer degree of granularity of locking a high degree of concurrency is possible
- (B) Locking prevents non – serializable schedules
- (C) Locking cannot take place at field level
- (D) An exclusive lock on data item X is granted even if a shared lock is already held on X
62 Which of the following statement on the view concept in SQL is invalid?
- (A) All views are not updateable
- (B) The views may be referenced in an SQL statement whenever tables are referenced
- (C) The views are instantiated at the time they are referenced and not when they are defined
- (D) The definition of a view should not have GROUP BY clause in it
63 Which of the following concurrency control schemes is not based on the serializability property?
- (A) Two – phase locking
- (B) Graph-based locking
- (C) Time-stamp based locking
- (D) None of these
64 Which of the following is a reason to model data?
- (A) Understand each user’s perspective of data
- (B) Understand the data itself irrespective of the physical representation
- (C) Understand the use of data across application areas
- (D) All of the above
65 If an entity can belong to only one lower level entity then the constraint is
- (A) Disjoint
- (B) Partial
- (C) Overlapping
- (D) Single
66 The common column is eliminated in
- (A) Theta join
- (B) Outer join
- (C) Natural join
- (D) Composed join
67 In SQL, testing whether a subquery is empty is done using
- (A) DISTINCT
- (B) UNIQUE
- (C) NULL
- (D) EXISTS
68 Use of UNIQUE while defining an attribute of a table in SQL means that the attribute values are
- (A) Distinct values
- (B) Cannot have NULL
- (C) Both A & B
- (D) Same as primary key
69 The cost of reading and writing temporary files while evaluating a query can be reduced by
- (A) Building indices
- (B) Pipelining
- (C) Join ordering
- (D) None of the above
70 A transaction is in __________ state after the final statement has been executed
- (A) Partially committed
- (B) Active
- (C) Committed
- (D) None of the above
71 In multiple granularity of locks SIX lock is compatible with
- (A) IX
- (B) IS
- (C) S
- (D) SIX
72 The statement that is executed automatically by the system as a side effect of the modification of the database is
- (A) Backup
- (B) Assertion
- (C) Recovery
- (D) Trigger
73 The normal form that is not necessarily dependency preserving is
- (A) 2NF
- (B) 3NF
- (C) BCNF
- (D) 4NF
74 The normalization was first proposed by ______________
- (A) Code
- (B) Codd
- (C) Boyce Codd
- (D) Boyce
75 The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
- (A) m – 1
- (B) m + 1
- (C) m * m
- (D) m
76 Which of the following is not a characteristic of a relational database model?
- (A) Table
- (B) Tree like structure
- (C) Complex logical relationship
- (D) Records
77 Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R
- (A) It will result in a deadlock situation
- (B) It will immediately be rejected
- (C) It will immediately be granted
- (D) It will be granted as soon as it is released by A
78 In E-R Diagram total participation is represented by
- (A) Double lines
- (B) Dashed lines
- (C) Single line
- (D) Triangle
79 The FD A -> B, DB -> C implies
- (A) DA -> C
- (B) A -> C
- (C) B -> A
- (D) DB -> A
80 The graphical representation of a query is ________
- (A) B-Tree
- (B) Graph
- (C) Query Tree
- (D) Directed graph
81 Union operator is a:
- (A) Unary Operator
- (B) Ternary Operator
- (C) Binary Operator
- (D) Not an operator
82 Relations produced from an E-R model will always be
- (A) First normal form
- (B) Second normal form
- (C) Third normal form
- (D) Fourth normal form
83 Manager salary details are hidden from the employee .This is
- (A) Conceptual level data hiding
- (B) External level data hiding
- (C) Physical level data hiding
- (D) None of these
84 Which of the following is true for network structure?
- (A) It is a physical representation of the data
- (B) It allows many to many relationship
- (C) It is conceptually simple
- (D) It will be the dominant database of the future
85 Which two files are used during operation of the DBMS?
- (A) Query languages and utilities
- (B) DML and query language
- (C) Data dictionary and transaction log
- (D) Data dictionary and query language
86 A list consists of last names, first names, addresses and pin codes. If all people in the list have the same last name and same pin code a useful key would be
- (A) The pin code
- (B) The last name
- (C) The compound key first name and last name
- (D) Tr from next page
87 In b-tree the number of keys in each node is ____ than the number of its children
- (A) One less
- (B) Same
- (C) One more
- (D) Half
88 The drawback of shadow paging technique is
- (A) Commit overhead
- (B) Data fragmentation
- (C) Garbage collection
- (D) All of these
89 Which normal form is considered adequate for normal relational database design?
- (A) 2NF
- (B) 5NF
- (C) 4NF
- (D) 3NF
90 Which of the following addressing modes permits relocation without any change over in the code?
- (A) Indirect addressing
- (B) Indexed addressing
- (C) PC relative addressing
- (D) Base register addressing
91 In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by
- (A) Jamming
- (B) Password
- (C) Documentation
- (D) Record lock
92 The values of the attribute describes a particular_____________
- (A) Entity set
- (B) File
- (C) Entity instance
- (D) Organization
93 Which of the following relational algebraic operations is not from set theory?
- (A) Union
- (B) Intersection
- (C) Cartesian product
- (D) Select
94 Which of the following ensures the atomicity of the transaction?
- (A) Transaction management component of DBMS
- (B) Application Programmer
- (C) Concurrency control component of DBMS
- (D) Recovery management component of DBMS
95 If both the functional dependencies: X->Y and Y->X hold for two attributes X and Y then the relationship between X and Y is
- (A) M:N
- (B) M:1
- (C) 01:01
- (D) 1:M
96 What will be the number of columns and rows respectively obtained for the operation, AB, if A B are Base union compatible and all the rows of a are common to B? Assume A has 4 columns and 10 rows; and B has 4 columns and 15 rows
- (A) 4,0
- (B) 0,0
- (C) 4,5
- (D) 8,5
97 For correct behaviour during recovery, undo and redo operation must be
- (A) Commutative
- (B) Associative
- (C) Idempotent
- (D) Distributive
98 Which of the following is not a consequence of non-normalized database?
- (A) Update Anomaly
- (B) Insertion Anomaly
- (C) Redundancy
- (D) Lost update problem
99 The part of a database management system which ensures that the data remains in a consistent state is
- (A) Authorization and integrity manager
- (B) Buffer manager
- (C) Transaction manager
- (D) File manager
100 Relationships among relationships can be represented in an-E-R model using
- (A) Aggregation
- (B) Association
- (C) Weak entity sets
- (D) Weak relationship sets