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[MCQ’s] Advance Data Management Technology

Module 01

Advance Data Management Technology

1. A collection of data designed to be used by different people is called a/an
a) Organization
b) Database
c) Relationship
d) Schema
Answer: b
Explanation: Database is a collection of related tables.

2. Which of the following is the oldest database model?
a) Relational
b) Deductive
c) Physical
d) Network
Answer: d
Explanation: The network model is a database model conceived as a flexible way of representing objects and their relationships.

3. Which of the following schemas does define a view or views of the database for particular users?
a) Internal schema
b) Conceptual schema
c) Physical schema
d) External schema
Answer: d
Explanation: An externally-defined schema can provide access to tables that are managed on any PostgreSQL, Microsoft SQL Server, SAS, Oracle, or MySQL database.

4. Which of the following is an attribute that can uniquely identify a row in a table?
a) Secondary key
b) Candidate key
c) Foreign key
d) Alternate key
Answer: b
Explanation: A Candidate Key can be any column or a combination of columns that can qualify as unique key in database.

5. Which of the following are the process of selecting the data storage and data access characteristics of the database?
a) Logical database design
b) Physical database design
c) Testing and performance tuning
d) Evaluation and selecting
Answer: b
Explanation: The physical design of the database optimizes performance while ensuring data integrity by avoiding unnecessary data redundancies.

6. Which of the following terms does refer to the correctness and completeness of the data in a database?
a) Data security
b) Data constraint
c) Data independence
d) Data integrity
Answer: d
Explanation: ACID property is satisfied by transaction in database.

7. The relationship between DEPARTMENT and EMPLOYEE is a
a) One-to-one relationship
b) One-to-many relationship
c) Many-to-many relationship
d) Many-to-one relationship
Answer: b
Explanation: One entity department is related to several employees.

8. A table can be logically connected to another table by defining a
a) Super key
b) Candidate key
c) Primary key
d) Unique key
Answer: c
Explanation: A superkey is a combination of attributes that can be uniquely used to identify a database record.

9. If the state of the database no longer reflects a real state of the world that the database is supposed to capture, then such a state is called
a) Consistent state
b) Parallel state
c) Durable state
d) Inconsistent state
Answer: d
Explanation: SQL data consistency is that whenever a transaction is performed, it sees a consistent database.

10. Ensuring isolation property is the responsibility of the
a) Recovery-management component of the DBMS
b) Concurrency-control component of the DBMS
c) Transaction-management component of the DBMS
d) Buffer management component in DBMS
Answer: b
Explanation: Concurrency control ensures that correct results for concurrent operations are generated while getting those results as quickly as possible.

11. Which of the following are steps in query processing?
a) Parsing and translation
b) Optimization
c) Evaluation
d) All of the mentioned
Answer: d
Explanation: Parsing and translation, optimization, evaluation are all the basic steps to process a query.

12. A relational algebra operation annotated with instructions on how to evaluate it is called _______
a) Evaluation algebra
b) Evaluation plan
c) Evaluation primitive
d) Evaluation engine
Answer: c
Explanation: A relational algebra operation annotated with instructions on how to evaluate it is called Evaluation primitive. The evaluation primitive is the basis for evaluation of queries.

13. A sequence of primitive operations that can be used to evaluate a query are called as __________
a) Query evaluation algebra
b) Query evaluation plan
c) Query evaluation primitive
d) Query evaluation engine
Answer: b
Explanation: A sequence of primitive operations that can be used to evaluate a query are called as Query evaluation plan. This is used by the query evaluation engine to process the queries.

14. The lowest level operator to access data in query processing is _______
a) File scan
b) File manipulation
c) File handling
d) File organization
Answer: a
Explanation: The lowest level operator to access data in query processing is file scan. File scans are algorithms that locate and retrieve records that fulfill a selection criterion.

15. Search algorithms that use an index are referred to as _________
a) Index scans
b) Search scans
c) Primary scans
d) Equality scans
Answer: a
Explanation: Search algorithms that use an index are called as index scans. We use the selection predicate to guide us through the choice of index to use in processing the query.

16. Sorting of relations that do not fit in memory is called as _______
a) Internal sorting
b) External sorting
c) Overflow sorting
d) Overload sorting
Answer: b
Explanation: Sorting of relations that do not fit in memory is called as external sorting.

17. A selection of the form satisfying the intersection of all records satisfying individual simple conditions is
a) Conjunctive selection
b) Disjunctive selection
c) Negation
d) None of the mentioned
Answer: a
Explanation: A selection of the form satisfying the intersection of all records satisfying individual simple conditions is a conjunctive selection. This is a form of complex selection predicate.

18. A selection of the form satisfying the union of all records satisfying individual simple conditions is
a) Conjunctive selection
b) Disjunctive selection
c) Negation
d) None of the mentioned
Answer: b
Explanation: A selection of the form satisfying the intersection of all records satisfying individual simple conditions is a disjunctive selection. This is a form of complex selection predicate.

19. A selection of the form giving all the records not satisfying simple individual conditions is ______
a) Conjunctive selection
b) Disjunctive selection
c) Negation
d) None of the mentioned
Answer: c
Explanation: A selection of the form giving all the records not satisfying simple individual conditions is negation. This is a form of complex selection predicate.

20. Which of the following can be implemented?
a) Conjunctive selection using one index
b) Conjunctive selection using composite index
c) Conjunctive selection by intersection of identifiers
d) All of the mentioned
Answer: d
Explanation: Conjunctive selection using one index, conjunctive selection using composite index and conjunctive selection by intersection of identifiers can be implemented. These are A7, A8, A9 algorithms that use an index.

21. A join of the form r ⨝r.A=s.B s is called as
a) Equi join
b) Left outer join
c) Right outer join
d) Full outer join
Answer: a
Explanation: A join of the form r ⨝r.A=s.B s is called as equi-join where A and B are sets of attributes of r and s respectively.

22. for each tuple tr in r do begin
FOR each tuple ts IN s do BEGIN
test pair (tr , ts ) TO see IF they satisfy the JOIN condition _
IF they do, ADD tr • ts TO the RESULT;
END

END

What type of join is this?
a) Equi join
b) Hash join
c) Nested loop join
d) Block nested loop join
Answer: c
Explanation: The given algorithm is called as a nested loop join because it basically consists of two nested for loops in it i.e. one for loop is inside another for loop.

23. If nested loop join is done on a per block basis rather than on a per tuple basis, it is called as
a) Equi join
b) Hash join
c) Nested loop join
d) Block nested loop join
Answer: d
Explanation: If nested loop join is done on a per block basis rather than on a per tuple basis, it is called as Block nested loop join. Within each pair of blocks, every tuple in one block is paired with every tuple in the other block to generate all possible combinations.

24. The merge join can be used to compute
a) Natural joins
b) Equi joins
c) Both the mentioned
d) None of the mentioned
Answer: c
Explanation: The merge join can be used to compute both equijoins and natural joins. This is also called as the sort-merge-join algorithm.

25. The ___________ merges the sorted relation with leaf entries of the secondary B+ tree index.
a) Merge join algorithm
b) Hybrid merge join algorithm
c) Hash join algorithm
d) Hybrid Hash join algorithm
Answer: b
Explanation: The Hybrid merge join algorithm merges the sorted relation with leaf entries of the secondary B+ tree index. The result contains tuples from the sorted relation and addresses for tuples from the unsorted relation.

26. The splitting of input until each partition of the build input fits the memory is called as ______
a) Temporary partitioning
b) Block partitioning
c) Recursive partitioning
d) Byte partitioning
Answer: c
Explanation: The splitting of input until each partition of the build input fits the memory is called as recursive partitioning.

27. Overflow resolution is performed when,
a) A hash index overflow is detected
b) Extra hash indices are to be added
c) When the number of partitions are to be increased
d) None of the mentioned
Answer: a
Explanation: Hash table overflows can be handled by either overflow resolution or overflow avoidance. Overflow resolution is performed when a hash index overflow is detected.

28. Which of the following is not a set operation
a) Union
b) Intersection
c) And operation
d) Set difference
Answer: c
Explanation: The AND operation is not a set operation, it is a logical bit operation.

29. Which of the following joins preserves the tuples of the relation on the left side of the operator?
a) Left outer join
b) Natural join
c) Right outer join
d) None of the mentioned
Answer: a
Explanation: Left outer join and full outer join both preserve the tuples on the left side of the operator.

30. State true or false: The aggregation functions can be implemented in the same way as that of duplicate elimination.
a) True
b) False
Answer: a
Explanation: The aggregation functions can be implemented in the same way as that of duplicate elimination.

31. If the results of one operation are passed on to the other, it is called as ________
a) Chain
b) Pipeline
c) Materialized
d) Tree
Answer: b
Explanation: If the results of one operation are passed on to the other, it is called as Pipelined. This can be used to evaluate several expressions simultaneously.

32. The result of each intermediate operation are created and then are used for valuation of the next level operations, this evaluation is called as ________
a) Chain evaluation
b) Pipeline evaluation
c) Materialized evaluation
d) Demand driven evaluation
Answer: c
Explanation: The result of each intermediate operation are created and then are used foe valuation of the next level operations, this evaluation is called as Materialized evaluation. This is not space effective as we need to construct the temporary relations which must be written to a disk.

33. If the system makes repeated requests for tuples from the operation at the top of the table, it is called as _________
a) Demand driven pipeline
b) Producer driven pipeline
c) Query driven pipeline
d) None of the mentioned
Answer: a
Explanation: If the system makes repeated requests for tuples from the operation at the top of the table, it is called as demand driven pipeline. Each time an operation receives a request for tuples, it computes the next tuple or tuples to be returned and then returns that tuple.

34. If the operations do not wait to produce tuples, then it is called as _________
a) Demand driven pipeline
b) Producer driven pipeline
c) Query driven pipeline
d) None of the mentioned
Answer: b
Explanation: If the operations do not wait to produce tuples, then it is called as producer driven pipeline. IT does not wait to produce tuples but it produces tuples eagerly.

35. State true or false: Sorting is an inherently blocking operation
a) True
b) False
Answer: a
Explanation: Sorting is an inherently blocking operation i.e. output is not given until all the tuples from their input are examined

36. State true or false: Join is an inherently blocking operation
a) True
b) False
Answer: b
Explanation: Join is not an inherently blocking algorithm. This is because all the tuples need not be examined to execute the join operation.

37. Which of the following techniques does not exist?
a) Pipelined join technique
b) Left pipelined join technique
c) Right pipelined join technique
d) None of the mentioned
Answer: d
Explanation: Pipelined join technique, both left and right are evaluation techniques that can be used to organize data.

38. State true or false: Hybrid hash join is partially pipelined on the probe relation
a) True
b) False
Answer: a
Explanation: Hybrid hash join is partially pipelined on the probe relation since it can output tuples from the first partition as tuples are received for the probe relation.

39. The usage of two buffers, with one continuing execution of the algorithm while the other is written is called as __________
a) Double execution
b) Multi tasking
c) Double buffering
d) Double algorithm
Answer: c
Explanation: The usage of two buffers, with one continuing execution of the algorithm while the other is written is called as Double buffering. This makes the algorithm quicker by performing CPU operations simultaneously with the I/O operations.

40. Which of the following functions does an iterator not provide
a) Open()
b) Next()
c) Close()
d) Wait()
Answer: d
Explanation: The iterator does not provide the wait() function but it provides open(), next() and close() operations.

41. If on every legal database instant, the two expressions generate the same set of tuples, the expressions are called as
a) Equal
b) Equivalent
c) Similar
d) Identical
Answer: b
Explanation: If on every legal database instant, the two expressions generate the same set of tuples, the expressions are called as Equivalent relational algebra expressions. The order of the tuples is completely irrelevant for equivalency.

42. State true or false: Selection operations are commutative
a) True
b) False
Answer: a
Explanation: Selection operations are commutative i.e. selection1(selection2(R)) = selection2(selection1(R)).

43. Which of the following operations are associative
a) Natural joins
b) Theta joins
c) Both the mentioned
d) None of the mentioned
Answer: c
Explanation: Both natural join operation and theta join operation are associative. The commutativity and associativity of the join operations are important for join reordering in query optimization.

44. Which of the following set operations is not commutative?
a) Union
b) Intersection
c) Set difference
d) None of the mentioned
Answer: c
Explanation: The set difference operation is not commutative. As the position of the set difference operator affects the result of the operation.

45. State true or false: The projection operation does not distribute over the union operation
a) True
b) False
Answer: b
Explanation: The projection operation distributes over the union operation.

46. If no rule can be derived from any combination of others then the set of rules is said to be ________
a) Primitive
b) Axiomatic
c) Minimal
d) Atomic
Answer: c
Explanation: A set of equivalence rules is said to be minimal if no rule can be derived from any combination of others. Query optimizers use minimal sets of equivalence rules.

47. Theta join operations are
a) Commutative
b) Associative
c) Distributive under projection
d) All of the mentioned
Answer: d
Explanation: The theta join operations are commutative, associative and are distributive under projection.

48. Which of the following operations is associative
a) Set union
b) Set intersection
c) Set difference
d) Theta join
Answer: d
Explanation: The theta join operation is associative within a certain set of conditions whereas the rest of the operations are non-associative in each and every condition.

49. Which of the following set operations does the selection operation distribute over?
a) Union
b) Intersection
c) Difference
d) All of the mentioned
Answer: d
Explanation: The selection operation distributes over Set union, intersection, set difference.

50. State true or false: Multiple equivalence rules can be used one after the other on a query
a) True
b) False
Answer: a
Explanation: Multiple equivalence rules can be used one after the other on a query or on parts of the query. This can be used to simplify the query greatly thus reducing its time complexity.

51. Which of the following information does the database system catalog store?
a) Number of tuples
b) Number of blocks
c) Size of a tuple of a relation
d) All of the mentioned
Answer: d
Explanation: The database system catalog stores the number of tuples, number of blocks, size of a tuple in a relation and the blocking factor in it as statistical data.

52. Most databases store the distribution of values for each attribute as a __________
a) Histogram
b) Pie chart
c) Line graph
d) None of the mentioned
Answer: a
Explanation: Most of the databases store the distribution of values for each attribute as a histogram.in which the values for the attributes are divided into various ranges.

53. What is the function of the equi-width histogram?
a) Adjusts boundaries of the ranges such that each range has the same number of values
b) Divides range of values into equal sized ranges
c) Divides the range of values into ideally sized ranges
d) Does not divide the range of values.
Answer: b
Explanation: The equi width histogram divides the range of values into equal sized ranges.

54. What kind of a sample must be used for statistical analysis?
a) A random sample
b) A sample having excessive representation of a relation
c) A sample having suppressive representation of a relation
d) None of the mentioned
Answer: a
Explanation: A random sample must be taken into consideration for statistical analysis because it gives a fair result on the data analysis.

55. The ________ SQL command generates statistics on a particular relation
a) Statistic
b) Analyze
c) Modify
d) Runstats
Answer: b
Explanation: The analyze command is used to generate statistics on a particular set of relations. The runstats command is also valid but not in SQL. It is used in IBM DB2.

56. The union of all records satisfying the individual simple conditions Oi is called as ________
a) Conjunctive selection
b) Disjunctive selection
c) Negation
d) None of the mentioned
Answer: b
Explanation: The union of all records satisfying the individual simple conditions Oi is called as disjunctive selection. It is a form of a complex selection.

57. The intersection of all records satisfying the individual simple conditions Oi is called as ________
a) Conjunctive selection
b) Disjunctive selection
c) Negation
d) None of the mentioned
Answer: a
Explanation: The intersection of all records satisfying the individual simple conditions Oi is called as conjunctive selection. It is a form of a complex selection.

58. State true or false: Estimation of the size of the result of a join is not possible
a) True
b) False
Answer: b
Explanation: Estimation of the result of a join is possible and can be done using the Cartesian product and intersections of the two relations. It is more complicated than estimating size of a selection.

59. Size estimation can be done for which of the following processes?
a) Projection
b) Aggregation
c) Set operation
d) All of the mentioned
Answer: d
Explanation: Size estimation can be done for projection, aggregation, set operations, join operations and also the selection operation.

60. The size of a _____ is simply V(A,r) where r is the relation and A is a distinct value
a) Projection
b) Outer join
c) Aggregation
d) Inner join
Answer: c
Explanation: The size of an aggregation is simply V(A,r) where r is the relation and A is a distinct value since there is one tuple in the aggregation for every distinct value in A.

61. A ________ explores the space of all query evaluation plans that are equivalent to a given query.
a) Cost based optimizer
b) Space based optimizer
c) Time based optimizer
d) None of the mentioned
Answer: a
Explanation: A cost based optimizer explores the space of all query evaluation plans that are equivalent to a given query, and chooses the one with the least estimated cost.

62. What is the disadvantage of cost based optimizers?
a) It is too expensive
b) It is inefficient in producing results
c) It does not perform the desired function
d) None of the mentioned
Answer: a
Explanation: Cost based optimizers may be expensive as exploring space of all possible plans might prove to be costly.

63. A particular sort order is said to be _________ sort order if it could be useful for a later operation.
a) Interesting
b) Reusable
c) Efficient
d) Good
Answer: a
Explanation: A particular sort order is said to be interesting-sort order if it could be useful for a later operation.

64. The rule that allows transformation of a logical operation to a physical operation is called
a) Logical equivalence rule
b) Physical equivalence rule
c) Memory equivalence rule
d) None of the mentioned
Answer: b
Explanation: The rule that allows transformation of a logical operation to a physical operation is called as a physical equivalence rule. It is a new class of equivalence rules.

65. State true or false: Making multiple copies of the same sub-expressions must be avoided
a) True
b) False
Answer: a
Explanation: For promoting space efficiency, making multiple copies of the same sub-expressions must be avoided.

66. Optimizers use __________ to reduce the cost of optimization.
a) Analyzers
b) Statistics
c) Heuristics
d) Caches
Answer: c
Explanation: Cost based optimizers may be expensive as exploring space of all possible plans might prove to be costly. So, optimizers use heuristics to reduce the cost of optimization.

67. The join orders where the right operand of each join is in one of the initial relations are called as ________
a) Right deep join orders
b) Left deep join orders
c) Outer join orders
d) None of the mentioned
Answer: b
Explanation: The join orders where the right operand of each join is in one of the initial relations are called as left deep join orders.

68. Caching and reuse of query plans is called as ________
a) Query caching
b) Plan caching
c) Plan memorizing
d) None of the mentioned
Answer: b
Explanation: Caching and reuse of query plans is called as plan caching. It is used because the optimal plan for the new constants may differ from the optimal plan for the initial values.

69. What technique is used for the evaluation of a query with a nested sub query?
a) Caching
b) Decorrelated evaluation
c) Correlated evaluation
d) Time based evaluation
Answer: c
Explanation: The technique used to evaluate a query with a nested sub query is called as correlated evaluation. It is not very efficient as a large number of I/O operations may occur.

70. The process of replacing a nested query with a query with a join is known as _________
a) Correlation
b) Decorrelation
c) Cache handling
d) Join replacement
Answer: b
Explanation: The process of replacing a nested query with a query with a join is known as decorrelation. It is more complicated when the nested sub query uses aggregate functions inside it.

Module 02

1. Collections of operations that form a single logical unit of work are called __________
a) Views
b) Networks
c) Units
d) Transactions
Answer: d
Explanation: Collections of operations that form a single logical unit of work are called transactions. A database system must ensure proper execution of transactions.

2. The “all-or-none” property is commonly referred to as _________
a) Isolation
b) Durability
c) Atomicity
d) None of the mentioned
Answer: c
Explanation: The all or none policy is commonly referred to as atomicity. It ensures that a work is either completed or not completed and there are no intermediate stages.

3. Which of the following is a property of transactions?
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
Answer: d
Explanation: Atomicity, Durability and Isolation are all properties of transactions.

4. Execution of translation in isolation preserves the _________ of a database
a) Atomicity
b) Consistency
c) Durability
d) All of the mentioned
Answer: b
Explanation: Execution of translation in isolation preserves the consistency of a database. It ensures that no other transaction is running concurrently.

5. Which of the following is not a property of a transaction?
a) Atomicity
b) Simplicity
c) Isolation
d) Durability
Answer: b
Explanation: Simplicity is not a property of a transaction. Atomicity, Isolation, Durability are all parts of ACID properties.

6. Which of the following systems is responsible for ensuring durability?
a) Recovery system
b) Atomic system
c) Concurrency control system
d) Compiler system
Answer: a
Explanation: The recovery system is responsible for the maintenance of durability. In addition, it also ensures atomicity.

7. Which of the following systems is responsible for ensuring isolation?
a) Recovery system
b) Atomic system
c) Concurrency control system
d) Compiler system
Answer: c
Explanation: The concurrency control system is responsible for ensuring isolation in a database system.

8. State true or false: Information residing in the volatile storage does not usually survive system crashes
a) True
b) False
Answer: a
Explanation: Information residing in the volatile storage does not usually survive system crashes but the information in stable storage can survive system crashes efficiently.

9. A transaction that has not been completed successfully is called as _______
a) Compensating transaction
b) Aborted transaction
c) Active transaction
d) Partially committed transaction
Answer: b
Explanation: Aborted transaction is a state after the transaction has been rolled back and the database has been restored to the state prior to the transaction.

10. Which of the following is not a transaction state?
a) Active
b) Partially committed
c) Failed
d) Compensated
Answer: d
Explanation: Compensated is not a transaction state. But active, partially committed and failed are different states of a transaction.

11. The execution sequences in concurrency control are termed as ________
a) Serials
b) Schedules
c) Organizations
d) Time tables
Answer: b
Explanation: The execution sequences in concurrency control are known as schedules.

12. The scheme that controls the interaction between executing transactions is called as _____
a) Concurrency control scheme
b) Multiprogramming scheme
c) Serialization scheme
d) Schedule scheme
Answer: a
Explanation: The scheme that controls the interaction between executing transactions is called as concurrency control scheme.

13. I and J are _________ if they are operations by different transactions on the same data item, and at least one of them is a write operation.
a) Conflicting
b) Overwriting
c) Isolated
d) Durable
Answer: a
Explanation: I and J are conflicting if they are operations by different transactions on the same data item, and at least one of them is a write operation.

14. If a schedule S can be transformed into a schedule S’ by a series of swaps of non-conflicting instructions, then S and S’ are
a) Non conflict equivalent
b) Equal
c) Conflict equivalent
d) Isolation equivalent
Answer: c
Explanation: If a schedule S can be transformed into a schedule S’ by a series of swaps of non-conflicting instructions, then S and S’ are conflict equivalent. Not all serial schedules are conflict equivalent to each other.

15. A schedule is __________ if it is conflict equivalent to a serial schedule.
a) Conflict serializable
b) Conflicting
c) Non serializable
d) None of the mentioned
Answer: a
Explanation: A schedule is conflict serializable if it is conflict equivalent to a serial schedule. The concept of conflict equivalence leads to the concept.

16. The set of ________ in a precedence graph consists of all the transactions participating in the schedule
a) Vertices
b) Edges
c) Directions
d) None of the mentioned
Answer: a
Explanation: The set of vertices in a precedence graph consists of all the transactions participating in the schedule. Precedence graph is a simple and efficient way of determining conflict serializability of the schedule.

17. A ___________of the transactions can be obtained by finding a linear order consistent with the partial order of the precedence graph.
a) Serializability order
b) Direction graph
c) Precedence graph
d) Scheduling scheme
Answer: a
Explanation: A Serializability order of the transactions can be obtained by finding a linear order consistent with the partial order of the precedence graph. This process is called as topological sorting.

18. State true or false: If I = read(Q) and J = read(Q) then the order of I and J does not matter.
a) True
b) False
Answer: a
Explanation: If I = read(Q) and J = read(Q) then the order of I and J does not matter because both I and J are read operations on the query.

19. State true or false: If I = read(Q) and J = write(Q) then the order of I and J does not matter.
a) True
b) False
Answer: b
Explanation: If I = read(Q) and J = write(Q) then the order of I and J matters because both I and J are different operations on the query. The order of execution determines the state of the database that is being read or written.

20. Which of the following is the most expensive method?
a) Timestamping
b) Plain locking
c) Predicate locking
d) Snapshot isolation
Answer: c
Explanation: Predicate locking is the most expensive method and is generally not used in most databases.

21. A transaction that performs only one operation is called as a _________
a) Partial schedule
b) Complete schedule
c) Dependent schedule
d) Independent schedule
Answer: a
Explanation: A transaction that performs only one operation is called as a partial schedule because we don’t include commit or rollback operations on them.

22. The phenomenon in which one failure leads to a series of transaction rollbacks is called as ________
a) Cascading rollback
b) Cascadeless rollback
c) Cascade cause
d) None of the mentioned
Answer: a
Explanation: The phenomenon in which one failure leads to a series of transaction rollbacks is called as cascading rollback. B=It is named so because one failure causes the rollback of several other transactions serially.

23. State true or false: Every cascadeless schedule is also recoverable
a) True
b) False
Answer: a
Explanation: Every cascadeless schedule is also recoverable because in a cascadeless schedule, the commit operations occur in the same sequence as that of write and read operations of two transactions respectively.

24. A ___________ is one where, for each pair of transactions Ti and Tj such that Tj reads a data item previously written by Ti , the commit operation of Ti appears before the commit operation of Tj
a) Partial schedule
b) Dependent schedule
c) Recoverable schedule
d) None of the mentioned
Answer: c
Explanation: A Recoverable schedule is one where, for each pair of transactions Ti and Tj such that Tj reads a data item previously written by Ti , the commit operation of Ti appears before the commit operation of Tj.

25. State true or false: Transactions can only run serially
a) True
b) False
Answer: b
Explanation: Transactions are safer run serially but can also be run concurrently.

26. Which of the following are the advantages of transaction concurrency?
a) Increased throughput
b) Increased utilization
c) Reduces average response time
d) All of the mentioned
Answer: d
Explanation: Concurrency in transactions allow increased throughput, utilization. They also reduce average response time.

27. The average time for a transaction to be completed after it has been submitted is called as __________
a) Minimum response time
b) Average response time
c) Average reaction time
d) Minimum reaction time
Answer: b
Explanation: The average time for a transaction to be completed after it has been submitted is called as Average response time. This gets decreased when concurrency is used in transactions.

28. If a schedule is equivalent to a serial schedule, it is called as a _________
a) Serializable schedule
b) Equivalent schedule
c) Committed schedule
d) None of the mentioned
Answer: a
Explanation: If a schedule is equivalent to a serial schedule, it is called as a Serializable schedule.

29. Which of the following is not a type of a schedule?
a) Partial schedule
b) Dependent schedule
c) Recoverable schedule
d) None of the mentioned
Answer: d
Explanation: All of the mentioned schedules i.e. partial schedule, dependent schedule, recoverable schedule are different types of schedules.

30. Which of the following is a transaction isolation level as specified by SQL standard?
a) Serializable
b) Repeatable read
c) Read committed
d) All of the mentioned
Answer: a
Explanation: Serializable, repeatable read, read committed and read uncommitted are the four levels of transactions.

31. State true or false: Serializable level may allow both serializable and non-serializable executions
a) True
b) False
Answer: a
Explanation: Serializable level generally allows only serializable executions but in some special cases, it may also allow non-serializable execution.

32. ________ allows only committed data to be read and further requires that no other transaction is allowed to update it between two reads of a data item by a transaction.
a) Read uncommitted
b) Serializable
c) Repeatable read
d) Read committed
Answer: c
Explanation: Repeatable read allows only committed data to be read and further requires that no other transaction is allowed to update it between two reads of a data item by a transaction. However, the transaction may not be serializable with respect to other transactions.

33. ________ allows only committed data to be read, but does not require repeatable reads
a) Read uncommitted
b) Serializable
c) Repeatable read
d) Read committed
Answer: d
Explanation: Read committed allows only committed data to be read, but does not require repeatable reads. For instance, between two reads of a data item by the transaction, another transaction may have updated the data item and committed.

34. ___________ allows uncommitted data to be read
a) Read uncommitted
b) Serializable
c) Repeatable read
d) Read committed
Answer: a
Explanation: Real uncommitted allows uncommitted data to be read. It is the lowest isolation level allowed by SQL.

35. State true or false: All the isolation levels disallow dirty writes
a) True
b) False
Answer: a
Explanation: All the isolation levels above additionally disallow dirty writes, that is, they Disallow writes to a data item that has already been written by another transaction that has not yet committed or aborted.

36. When is a timestamp allotted
a) When execution begins
b) When execution is taking place
c) When execution is completed
d) None of the mentioned
Answer: a
Explanation: Timestamp is allotted when execution of a transaction begins.

37. In ___________ isolation each transaction is given its own version of the database
a) Timestamp
b) Snapshot
c) Lock based
d) All of the mentioned
Answer: b
Explanation: In snapshot isolation, each transaction is given its own version or snapshot of the database on which it can operate.

38. What is the disadvantage of locking?
a) Does not control concurrency
b) Is not atomic
c) Is not durable
d) Has a poor degree of concurrency
Answer: Locking has a poor degree of concurrency. It in fact has no concurrency at all.

39. If a transaction has obtained a __________ lock, it can read but cannot write on the item
a) Shared mode
b) Exclusive mode
c) Read only mode
d) Write only mode
Answer: a
Explanation: If a transaction Ti has obtained a shared-mode lock (denoted by S) on item Q, then Ti can read, but cannot write, Q.

40. If a transaction has obtained a ________ lock, it can both read and write on the item
a) Shared mode
b) Exclusive mode
c) Read only mode
d) Write only mode
Answer: b
Explanation: If a transaction has obtained an exclusive mode lock, then it can both read and write on the item on which it in operating.

41. A transaction can proceed only after the concurrency control manager ________ the lock to the transaction
a) Grants
b) Requests
c) Allocates
d) None of the mentioned
Answer: a
Explanation: A transaction can proceed only after the concurrency control manager grants the lock to the transaction.

42. If a transaction can be granted a lock on an item immediately in spite of the presence of another mode, then the two modes are said to be ________
a) Concurrent
b) Equivalent
c) Compatible
d) Executable
Answer: c
Explanation: If a transaction can be granted a lock on an item immediately in spite of the presence of another mode, then the two modes are said to be compatible.

43. A transaction is made to wait until all ________ locks held on the item are released
a) Compatible
b) Incompatible
c) Concurrent
d) Equivalent
Answer: a
Explanation: A transaction is made to wait until all compatible locks held on the item are released. This ensures that no other transaction is concurrently accessing the same item.

44. State true or false: It is not necessarily desirable for a transaction to unlock a data item immediately after its final access
a) True
b) False
Answer: a
Explanation: It is not necessarily desirable for a transaction to unlock a data item immediately after its final access because serializability may be violated due to this.

45. The situation where no transaction can proceed with normal execution is known as ________
a) Road block
b) Deadlock
c) Execution halt
d) Abortion
Answer: b
Explanation: The situation where no transaction can proceed with normal execution is known as a deadlock.

46. The protocol that indicates when a transaction may lock and unlock each of the data items is called as __________
a) Locking protocol
b) Unlocking protocol
c) Granting protocol
d) Conflict protocol
Answer: a
Explanation: The protocol that indicates when a transaction may lock and unlock each of the data items is called as locking protocol. Locking protocols restrict the number of schedules.

47. If a transaction Ti may never make progress, then the transaction is said to be ____________
a) Deadlocked
b) Starved
c) Committed
d) Rolled back
Answer: b
Explanation: If a transaction Ti may never make progress, then the transaction is said to be starved.

48. The two phase locking protocol consists which of the following phases?
a) Growing phase
b) Shrinking phase
c) More than one of the mentioned
d) None of the mentioned
Answer: c
Explanation: The two phased locking protocol consists of the growing phase and the shrinking phase.

49. If a transaction may obtain locks but may not release any locks then it is in _______ phase
a) Growing phase
b) Shrinking phase
c) Deadlock phase
d) Starved phase
Answer: a
Explanation: If a transaction may obtain locks but may not release any locks then it is in growing phase. Growing phase is a phase in two phased locking protocol.

50. If a transaction may release locks but may not obtain any locks, it is said to be in ______ phase
a) Growing phase
b) Shrinking phase
c) Deadlock phase
d) Starved phase
Answer: b
Explanation: If a transaction may release locks but may not obtain any locks, it is said to be in shrinking phase. Shrinking phase is a phase in two phased locking protocol.

51. A system is in a _______ state if there exists a set of transactions in which every transaction is waiting for another transaction in the set.
a) Deadlock
b) Starved
c) Isolated
d) None of the mentioned
Answer: a
Explanation: A system is in a deadlock state if there exists a set of transactions in which every transaction is waiting for another transaction in the set.

52. Which of the following is not a method in deadlock handling
a) Deadlock prevention
b) Deadlock detection
c) Deadlock recovery
d) Deadlock distribution
Answer: d
Explanation: Deadlock distribution is not a method in deadlock handling whereas, deadlock prevention is followed by deadlock detection and deadlock recovery.

53. Deadlocks can be prevented using
a) Preemption and transaction rollbacks
b) Wait and die scheme
c) Wound-wait scheme
d) All of the mentioned
Answer: d
Explanation: Preemption and transaction rollbacks, wait and die scheme, wound wait scheme are all different methods of deadlock prevention.

54. State true or false: Wait die scheme is a non-preemptive technique
a) True
b) False
Answer: a
Explanation: The wait-die scheme is a non-preemptive technique. When transaction Ti requests a data item currently held by Tj , Ti is allowed to wait only if it has a timestamp smaller than that of Tj (that is, Ti is older than Tj ). Otherwise, Ti is rolled back (dies).

55. Lock timeouts have which of the following advantages?
a) Unnecessary rollbacks do not occur
b) Transactions do not starve
c) It is easy to implement
d) All of the mentioned
Answer: d
Explanation: In lock timeout method, unnecessary rollbacks do not occur, transactions do not starve and it is also easy to implement and is hence widely used if transactions are short and long waits are likely to be due to deadlocks.

56. The _________ graph describes deadlocks precisely
a) Wound wait graph
b) Wait die graph
c) Wait for graph
d) None of the mentioned
Answer: c
Explanation: The wait for graph describes deadlocks precisely. Existence of a cycle in this graph implies that a deadlock will occur.

57. How do we generally recover from a deadlock?
a) By aborting all the transactions
b) By rolling back all the transactions
c) By rolling back only a selected number of transactions
d) None of the mentioned
Answer: c
Explanation: We generally recover from deadlocks by rolling back only a selected number of transactions

58. State true or false: Partial rollback is not possible.
a) True
b) False
Answer: b
Explanation: Partial rollback is possible but it requires the system too maintain an additional amount of information on the states of the transactions.

59. Which of the following steps must be taken while choosing a victim?
a) Avoiding starvation
b) Number of transactions involved in rollback
c) Data items used by the transaction
d) All of the mentioned
Answer: d
Explanation: While choosing a victim we much choose the one with a minimum cost. That is the one which avoids starvation, the one with the least number of transaction involved in the rollback and the one with the least amount of data items used.

60. Which of the following cannot be used to implement a timestamp
a) System clock
b) Logical counter
c) External time counter
d) None of the mentioned
Answer: c
Explanation: An external time counter cannot be used to implement a timestamp. System clock and a logical counter can be used.

61. A logical counter is _________ after a new timestamp has been assigned
a) Incremented
b) Decremented
c) Doubled
d) Remains the same
Answer: a
Explanation: A logical counter is incremented after a new timestamp has been assigned everytime.

62. W-timestamp(Q) denotes?
a) The largest timestamp of any transaction that can execute write(Q) successfully
b) The largest timestamp of any transaction that can execute read(Q) successfully
c) The smallest timestamp of any transaction that can execute write(Q) successfully
d) The smallest timestamp of any transaction that can execute read(Q) successfully
Answer: a
Explanation: W-timestamp(Q) denotes The largest timestamp of any transaction that can execute write(Q) successfully.

63. R-timestamp(Q) denotes?
a) The largest timestamp of any transaction that can execute write(Q) successfully
b) The largest timestamp of any transaction that can execute read(Q) successfully
c) The smallest timestamp of any transaction that can execute write(Q) successfully
d) The smallest timestamp of any transaction that can execute read(Q) successfully
Answer: b
Explanation: R-timestamp(Q) denoted the largest timestamp of any transaction that can execute read(Q) successfully.

64. A ________ ensures that any conflicting read and write operations are executed in timestamp order
a) Organizational protocol
b) Timestamp ordering protocol
c) Timestamp execution protocol
d) 802-11 protocol
Answer: b
Explanation: A timestamp ordering protocol ensures that any conflicting read and write operations are executed in timestamp order.

65. The default timestamp ordering protocol generates schedules that are
a) Recoverable
b) Non-recoverable
c) Starving
d) None of the mentioned
Answer: b
Explanation: The timestamp ordering protocol generates schedules that are non-recoverable. But it can be extended to make the schedules recoverable.

66. State true or false: The Thomas write rule has a greater potential concurrency than the timestamp ordering protocol
a) True
b) False
Answer: a
Explanation: The Thomas write rule has a greater potential concurrency than the timestamp ordering protocol. This is because it is a modified version of the timestamp ordering protocol in which obsolete write operations can be ignored under certain circumstances.

67. Which of the following timestamp based protocols generates serializable schedules?
a) Thomas write rule
b) Timestamp ordering protocol
c) Validation protocol
d) None of the mentioned
Answer: a
Explanation: Thomas write rule protocol generates serializable schedules that no other protocol can generate.

68. In timestamp ordering protocol, suppose that the transaction Ti issues read(Q) and TS(Ti)<W-timestamp(Q), then
a) Read operation is executed
b) Read operation is rejected
c) Write operation is executed
d) Write operation is rejected
Answer: b
Explanation: Suppose that transaction Ti issues read(Q). If TS(Ti ) < W-timestamp(Q), then Ti needs to read a value of Q that was already overwritten. Hence, the read operation is rejected, and Ti is rolled back.

69. In timestamp ordering protocol, suppose that the transaction Ti issues write(Q) and TS(Ti)<W-timestamp(Q), then
a) Read operation is executed
b) Read operation is rejected
c) Write operation is executed
d) Write operation is rejected
Answer: d
Explanation: In timestamp ordering protocol, suppose that the transaction Ti issues write(Q) and TS(Ti)<W-timestamp(Q), then the value of Q that Ti is producing was needed previously, and the system assumed that the value would never be produced. Hence the system rejects the write(Q) operation and the transaction Ti rolls back.

Module 03

1. MySQL uses security based on ACL which stands for ______________
a) Access Control Language
b) Access Control Lists
c) Automatic Control Lists
d) Automatic Control Language
Answer: b
Explanation: MySQL uses security based on Access Control Lists (ACLs) for all connections, queries and other operations that users can attempt to perform. There is support for SSL encrypted connections.

2. The mysql client writes a record of executed statements to a history file on Unix.
a) True
b) False
Answer: a
Explanation: On Unix the mysql client writes a record of the executed statements to a history file. By default this file is named as ‘.mysql_history’. It is created in the home directory.

3. A password applies globally to an account.
a) True
b) False
Answer: a
Explanation: In the MySQL privilege system, a password applies globally to an account. A password cannot be explicitly associated with a specific object such as a database, table, or routine.

4. The context in which the privilege ‘CREATE TABLESPACE’ applies is ______________
a) Server administration
b) Tables
c) Stored routines
d) Views
Answer: a
Explanation: The column name associated with the privilege ‘CREATE TABLESPACE’ is ‘Create_tablespace_priv’. The context in which this privilege is being used is the server administration.

5. The number of languages that have interfaces to bind to the C API of MySQL among these is ______________

Perl, PHP, Python
a) 0
b) 1
c) 2
d) 3
Answer: d
Explanation: The client library provides the means through which the MySQL bindings for other languages can be built on top of the C API. This type of interface exists for Perl, PHP, Python and others.

6. The language that is the core for APIs and communication in MySQL is ______________
a) C
b) C++
c) Python
d) Ruby
Answer: a
Explanation: In order to provide application development, MySQL provides a client library written in the C programming language. It enables access to MySQL databases from a C program.

7. The most general purpose language is ______________
a) C
b) Perl
c) Python
d) PHP
Answer: a
Explanation: C is a general purpose language, so in principle, it can be used for anything. C tends to be used more often for standalone programs rather than for Web programming in practice.

8. The language in which image processing is least simple is ______________
a) PHP
b) Perl
c) Python
d) C
Answer: d
Explanation: It is not as easy to perform text processing and memory management in C than it is in languages like Perl and PHP. These capabilities tend to be heavily used in web applications.

9. The option necessary to compile a C program havin math functions is ______________
a) -lm
b) -ln
c) -lp
d) -lq
Answer: a
Explanation: To compile a program written in the C language, it is compiled by issuing the option ‘-lm’. The examples of some math functions found in ‘math.h’ are floor(), sqrt(), pow(), log().

10. What is the option for specifying the executable name while compiling with gcc?
a) -e
b) -o
c) -a
d) -b
Answer: b
Explanation: When a C program is compiled with gcc, the option -o is issued in order to specify the name of the executable that is created after compilation. The default name given is ‘a.out’.

11. An ________ is a set of entities of the same type that share the same properties, or attributes.
a) Entity set
b) Attribute set
c) Relation set
d) Entity model
Answer: a
Explanation: An entity is a “thing” or “object” in the real world that is distinguishable from all other objects.

12. Entity is a _________
a) Object of relation
b) Present working model
c) Thing in real world
d) Model of relation
Answer: c
Explanation: For example, each person in a university is an entity.

13. The descriptive property possessed by each entity set is _________
a) Entity
b) Attribute
c) Relation
d) Model
Answer: b
Explanation: Possible attributes of the instructor entity set are ID, name, dept name, and salary.

14. The function that an entity plays in a relationship is called that entity’s _____________
a) Participation
b) Position
c) Role
d) Instance
Answer: c
Explanation: A relationship is an association among several entities.

15. The attribute name could be structured as an attribute consisting of first name, middle initial, and last name. This type of attribute is called
a) Simple attribute
b) Composite attribute
c) Multivalued attribute
d) Derived attribute
Answer: b
Explanation: Composite attributes can be divided into subparts (that is, other attributes).

16. The attribute AGE is calculated from DATE_OF_BIRTH. The attribute AGE is
a) Single valued
b) Multi valued
c) Composite
d) Derived
Answer: d
Explanation: The value for this type of attribute can be derived from the values of other related attributes or entities.

17. Not applicable condition can be represented in relation entry as
a) NA
b) 0
c) NULL
d) Blank Space
Answer: c
Explanation: NULL always represents that the value is not present.

18. Which of the following can be a multivalued attribute?
a) Phone_number
b) Name
c) Date_of_birth
d) All of the mentioned
Answer: a
Explanation: Name and Date_of_birth cannot hold more than 1 value.

19. Which of the following is a single valued attribute
a) Register_number
b) Address
c) SUBJECT_TAKEN
d) Reference
Answer: a
Explanation: None.

20. In a relation between the entities the type and condition of the relation should be specified. That is called as______attribute.
a) Desciptive
b) Derived
c) Recursive
d) Relative
Answer: a
Explanation: Consider the entity sets student and section, which participate in a relationship set takes. We may wish to store a descriptive attribute grade with the relationship to record the grade that a student got in the class.

21. Which classes does spatial data types in MySQL correspond to?
a) OpenGSS
b) OpenGIS
c) ClosedGSS
d) ClosedGIS
Answer: b
Explanation: MySQL has spatial data types that correspond to OpenGIS classes. Some of them that hold single geometry values are ‘GEOMETRY’, ‘POINT’, ‘LINESTRING’ and ‘POLYGON’. Some can hold a collection of values.

22. Which type can store a collection of objects of any type?
a) GEOMETRYCOLLECTION
b) MULTIPOINT
c) MULTILINESTRING
d) MULTIPOLYGON
Answer: a
Explanation: ‘GEOMETRYCOLLECTION’ can store a collection of objects of any type. The other collection types like ‘MULTIPOINT’, ‘MULTILINESTRING’, ‘MULTIPOLYGON’ and ‘GEOMETRYCOLLECTION’ restrict collection members to those having a particular geometry type.

23. SPATIAL indexes cannot be created on NOT NULL spatial columns.
a) True
b) False
Answer: b
Explanation: The ‘SPATIAL’ indexes can be created on ‘NOT NULL’ spatial columns. Therefore, if it is planned to index the column, it would need to be declared as NOT NULL. This type can be used in many ways.

24. MySQL does not automatically convert a date or time value to a number if the value is used in a numeric context.
a) True
b) False
Answer: b
Explanation: MySQL automatically converts a date or time value into a number if the value is used in a numeric context and vice versa. A ‘zero’ value can also be represented in MySQL.

25. What is the generic handle whose meaning depends on context?
a) $dbh
b) $sth
c) $fh
d) $h
Answer: d
Explanation: The variable named ‘$fh’ is a handle to an open file. ‘$h’ is a generic handle and the meaning depends on context. ‘$dbh’ is a handle to a database object. ‘$sth’ is a handle to a query object.

26. What is the non handle array representing a row of values?
a) $rc
b) $rv
c) $rows
d) $ary
Answer: d
Explanation: The Perl Non-handle variable ‘$ary’ is an array or list representing a row of values returned by a query. ‘$rc’ returns code from operations that return true or false. ‘$rv’ returns value from operations that return an integer. ‘$rows’ returns value from operations that return a row count.

27. The mode of search is the search string parsed into words and the search looks for rows is ______________
a) Boolean mode
b) Natural language
c) Query expansion
d) Cross mode
Answer: b
Explanation: In MySQL, a full text search capability is provided, which enables to look for words or phrases without using pattern-matching operations. There are three kinds of full text searches.

28. In which mode is the indicator of the presence/absence of a word in search used?
a) Natural language
b) Boolean mode
c) Query expansion
d) Cross mode
Answer: b
Explanation: A full text search capability is provided in MySQL. It facilitates to look for words or phrases without using pattern-matching operations. Boolean search is one of the three modes.

Module 04

1. What does top down process follow?
a) The overall flow of activity during product design resolution is from higher to lower levels
b) The overall flow of activity during product design resolution is from lower to higher levels
c) All of the mentioned
d) None of the mentioned
Answer: a
Explanation: Top down layer focuses on higher to lower abstraction.

2. What are the most common scenarios for resolutions?
a) Designers frequently work bottom up or skip levels of abstraction
b) To specify some part of product design to its physical level details before others are specified
c) All of the mentioned
d) None of the mentioned
Answer: c
Explanation: The choices represents the most common scenarios worked out under resolution techniques.

3. Lower level of abstraction includes?
a) Product features
b) Functions
c) Properties
d) All of the mentioned
Answer: d
Explanation: Lower abstraction includes all the choices mentioned.

4. Product design is mainly?
a) Top-down approach
b) Bottom-up approach
c) Top-down & Bottom-up approach
d) None of the mentioned
Answer: a
Explanation: Product design is top down approach.

5. The user-centered design comprises of which of these principles?
a) Stakeholder focus
b) Empirical Evaluation
c) Iteration
d) All of the mentioned
Answer: d
Explanation: It includes all the following principles.

6. Collection of stakeholder needs is called?
a) Requirements elicitation
b) Requirements validation
c) Needs Elicitation
d) Requirements & Needs elicitation
Answer: d
Explanation: Collection of stakeholders needs are called needs elicitation, needs identification, requirements elicitation.

7. Understanding Stakeholder needs are called?
a) Needs analysis
b) Needs elicitation
c) Needs identification
d) All of the mentioned
Answer: a
Explanation: Understanding of these needs are called needs analysis.

8. Confirming with stakeholder that a product design satisfies their needs and desires are called?
a) Requirements validation
b) Requirements elicitation
c) Requirements analysis
d) None of the mentioned
Answer: a
Explanation: It is also called as validation or requirement validation for confirming with stakeholder that a product design satisfies.

9. Stakeholder role in analyzing needs?
a) Answer questions
b) Clarify project mission statement
c) Review and validate models and documents
d) Answer questions, Review and validate models and documents
Answer: d
Explanation: Clarifying project mission statement comes for analyzing product design problem.

10. Stakeholder role for Generate/Improve alternatives?
a) Participate in generation and improvement
b) Answer the question
c) Be subject of empirical studies
d) All of the mentioned
Answer: a
Explanation: Generate or improving alternatives includes active participation.

11. In distributed system, each processor has its own ___________
a) local memory
b) clock
c) both local memory and clock
d) none of the mentioned
Answer: c
Explanation: None.

12. If one site fails in distributed system then ___________
a) the remaining sites can continue operating
b) all the sites will stop working
c) directly connected sites will stop working
d) none of the mentioned
Answer: a
Explanation: None.

13. Network operating system runs on ___________
a) server
b) every system in the network
c) both server and every system in the network
d) none of the mentioned
Answer: a
Explanation: None.

14. Which technique is based on compile-time program transformation for accessing remote data in a distributed-memory parallel system?
a) cache coherence scheme
b) computation migration
c) remote procedure call
d) message passing
Answer: b
Explanation: None.

15. Logical extension of computation migration is ___________
a) process migration
b) system migration
c) thread migration
d) data migration
Answer: a
Explanation: None.

16. Processes on the remote systems are identified by ___________
a) host ID
b) host name and identifier
c) identifier
d) process ID
Answer: b
Explanation: None.

17. Which routing technique is used in a distributed system?
a) fixed routing
b) virtual routing
c) dynamic routing
d) all of the mentioned
Answer: d
Explanation: None.

18. In distributed systems, link and site failure is detected by ___________
a) polling
b) handshaking
c) token passing
d) none of the mentioned
Answer: b
Explanation: None.

19. The capability of a system to adapt the increased service load is called ___________
a) scalability
b) tolerance
c) capacity
d) none of the mentioned
Answer: a
Explanation: None.

20. Internet provides _______ for remote login.
a) telnet
b) http
c) ftp
d) rpc
Answer: a
Explanation: None.

21. What are the advantages of Replication of data in Distributed database?
a.Avaliability, Parallelism, Increased data transfer
b.Availability, Parallelism, Reduced data transfer
c.Availability, Increased parallelism, Cost of updates
d.All of the above
Answer: b

22. A fragmentation technique wherein every tuple of a table is assigned to one or more fragments as a result of fragmentation is called ________________ .
a.Vertical Fragmentation
b.Horizontal Fragmentation
c.Hybrid Fragmentation
d.None of the above
Answer: b

Assume a relation EMP as given below:
EMP(EmpNo, EName, Job, Sal, Department)
Furthermore, assume that there are two applications which are accessing the above mentioned table. One application typically retrieves information about employees who earn more than Rs5.000, the other application typically manages information about ‘clerks’ (job). Also, assume that there are employees with other designations and different salaries stored in EMP. With this information, answer the questions 3 to 6.

23. Which of the following are the simple predicates which can be directly extracted from the given applications?
a.{Job = clerk, Salary>5000}
b.{Job = clerk, Salary<5000}
c.{Job = Manager, Salary>5000}
d.{Job = Manager, Salary<5000}
Answer: a

24. How many valid minterm predicates we can derive for the above said problem?
a.4
b.5
c.3
d.2
Answer: a

25. Assume that the departments are ‘Finance’, ‘Production’, and ‘Design’. If there is one more application which accesses the informatoin frequently based on the ‘Finance’ department, what would be the number of valid minterm fragments?
a.5
b.6
c.7
d.8
Answer: d

26. If by mistake, I miss one of the valid minterm fragments. What would be the effect of that in fragmentation?
a.Causes skew
b.Reconstruction of EMP will be unsuccessful
c.Slows down the database access
d.None
Answer: b

27. Which of the following failures are unique to distributed database systems?
a.Failure of a site
b.Loss of messages
c.Network Partition
d.All the above
Answer: d

28. For the given set of simple predicates Pr, how many min-term predicates we can derive (including invalid ones). Pr = {Branch = “Vellore”, Branch = “Chennai”, Salary <=20000, Salary > 20000} Assumptions: Consider there are five different branches.
a.4
b.8
c.16
d.32
Answer: c

29. In a distributed database application, if we have very many number of read only queries than update queries then ______________ allocation technique is advantageous.
a.Hybrid Fragmentation
b.Horizontal Fragmentation
c.Replication
d.Vertical Fragmentation
Answer: c

30. Which of the following would be the advantage of Database Fragmentation?
a.Most of the operations are local to any sites
b.Reduced Network Traffic
c.Parallel processing
d.All the above
Answer: d

31. Which of the following would improve the availability of resources especially for reading in a distributed database system?
a) Fragmentation of database
b) Replication of database
c) Defragmentation of database
d) Tuning of database
Answer: (b) Replication of database
Replication in distributed database system is a concept of having multiple copies of same data at different sites to increase the availability of resources.

32. ______________ is very much required to process a query in a distributed database.
a) Global System Catalog
b) Database Views
c) Triggers
d) None of the above
Answer: (a) Global System Catalog
Data dictionary is an important component in DBMS. It is used for manipulating information regarding all database components in a DBMS. It stores information regarding tables, views, name of the tables, attributes, constraint details etc. Global System Catalog is just like Data Dictionary for Distributed Database System. It stores information like what and where about the data in a DDB.

33. Reliability and availability of a “Centralized Data Allocation” method is ___________ when compared to a “Completely Replicated Data Allocation“.
a) Highest
b) Average
c) Lowest
d) Not applicable
Answer: (c) Lowest
Replication in distributed database system is a concept of having multiple copies of same data at different sites to increase the availability of resources.
In a centralized data allocation method only one copy of data available. Hence, availability is lowest. Due to only one copy of data, it is prone to single point of failure.
In a completely replicated data allocation method, due to availability of more than one copy of same data, the reliability and availability is high compare to centralized data allocation method.

34. If one site ABORTs while processing part of a distributed transaction t, all other sites processing part of t will also ABORT t. Which of the following ensures this?
a) Two phase locking protocol
b) Two phase commit protocol
c) Three phase commit protocol
d) All of the above
Answer: (b) Two phase commit protocol
In two phase commit protocol, the transaction coordinator decides to ABORT the entire transaction if any of the participating sites cannot commit for some reasons.

35. Which of the following transparencies in distributed database design requires the end user or programmer to specify the database fragment names but need not specify where these fragments are located?
a) Transaction
b) Location
c) Local mapping
d) Fragmentation
Answer: (b) Location
Location transparency refers to the fact that the command used to perform a task is independent of both the location of the data and the system on which an operation is carried out.

36. Relational Algebra is a __________ query language that takes two relations as input and produces another relation as an output of the query.
a) Relational
b) Structural
c) Procedural
d) Fundamental
Answer: c
Explanation: This language has fundamental and other operations which are used on relations.

37. Which of the following is a fundamental operation in relational algebra?
a) Set intersection
b) Natural join
c) Assignment
d) None of the mentioned
Answer: d
Explanation: The fundamental operations are select, project, union, set difference, Cartesian product, and rename.

38. Which of the following is used to denote the selection operation in relational algebra?
a) Pi (Greek)
b) Sigma (Greek)
c) Lambda (Greek)
d) Omega (Greek)
Answer: b
Explanation: The select operation selects tuples that satisfy a given predicate.

39. For select operation the ________ appear in the subscript and the ___________ argument appears in the paranthesis after the sigma.
a) Predicates, relation
b) Relation, Predicates
c) Operation, Predicates
d) Relation, Operation
Answer: a
Explanation: None.

40. The ___________ operation, denoted by −, allows us to find tuples that are in one relation but are not in another.
a) Union
b) Set-difference
c) Difference
d) Intersection
Answer: b
Explanation: The expression r − s produces a relation containing those tuples in r but not in s.

41. Which is a unary operation:
a) Selection operation
b) Primitive operation
c) Projection operation
d) Generalized selection
Answer: d
Explanation: Generalization Selection takes only one argument for operation.

42. Which is a join condition contains an equality operator:
a) Equijoins
b) Cartesian
c) Natural
d) Left
Answer: a
Explanation: None.

43. In precedence of set operators, the expression is evaluated from
a) Left to left
b) Left to right
c) Right to left
d) From user specification
Answer: b
Explanation: The expression is evaluated from left to right according to the precedence.

44. Which of the following is not outer join?
a) Left outer join
b) Right outer join
c) Full outer join
d) All of the mentioned
Answer: d
Explanation: The FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins.

45. The assignment operator is denoted by
a) ->
b) <-
c) =
d) ==
Answer: b
Explanation: The result of the expression to the right of the ← is assigned to the relation variable on the left of the ←.

46. Consider money is transferred from (1)account-A to account-B and (2) account-B to account-A. Which of the following form a transaction?
a) Only 1
b) Only 2
c) Both 1 and 2 individually
d) Either 1 or 2
Answer: c
Explanation: The term transaction refers to a collection of operations that form a single logical unit of work.

47. A transaction is delimited by statements (or function calls) of the form __________
a) Begin transaction and end transaction
b) Start transaction and stop transaction
c) Get transaction and post transaction
d) Read transaction and write transaction
Answer: a
Explanation: The transaction consists of all operations executed between the begin transaction and end transaction.

48. Identify the characteristics of transactions
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
Answer: d
Explanation: Because of the above three properties, transactions are an ideal way of structuring interaction with a database.

49. Which of the following has “all-or-none” property?
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
Answer: a
Explanation: Either all operations of the transaction are reflected properly in the database, or none are.

50. The database system must take special actions to ensure that transactions operate properly without interference from concurrently executing database statements. This property is referred to as
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
Answer: c
Explanation: Even though multiple transactions may execute concurrently, the system guarantees that, for every pair of transactions Ti and Tj, it appears to Ti that either Tj finished execution before Ti started or Tj started execution after Ti finished.

51. The property of a transaction that persists all the crashes is
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
Answer: b
Explanation: After a transaction completes successfully, the changes it has made to the database persist, even if there are system failures.

52. __________ states that only valid data will be written to the database.
a) Consistency
b) Atomicity
c) Durability
d) Isolation
Answer: a
Explanation: If for some reason, a transaction is executed that violates the database’s consistency rules, the entire transaction will be rolled back and the database will be restored to a state consistent with those rules.

53. Transaction processing is associated with everything below except
a) Producing detail summary or exception reports
b) Recording a business activity
c) Confirming an action or triggering a response
d) Maintaining a data
Answer: c
Explanation: Collections of operations that form a single logical unit of work are called transactions.

54. The Oracle RDBMS uses the ____ statement to declare a new transaction start and its properties.
a) BEGIN
b) SET TRANSACTION
c) BEGIN TRANSACTION
d) COMMIT
Answer: b
Explanation: Commit is used to store all the transactions.

55. ____ means that the data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.
a) Consistency
b) Atomicity
c) Durability
d) Isolation
Answer: d
Explanation: Even though multiple transactions may execute concurrently, the system guarantees that, for every pair of transactions Ti and Tj, it appears to Ti that either Tj finished execution before Ti started or Tj started execution after Ti finished.

Module 05

1. OLAP stands for
a) Online analytical processing
b) Online analysis processing
c) Online transaction processing
d) Online aggregate processing
Answer: a
Explanation: OLAP is the manipulation of information to support decision making.

2. Data that can be modeled as dimension attributes and measure attributes are called _______ data.
a) Multidimensional
b) Singledimensional
c) Measured
d) Dimensional
Answer: a
Explanation: Given a relation used for data analysis, we can identify some of its attributes as measure attributes, since they measure some value, and can be aggregated upon.Dimension attribute define the dimensions on which measure attributes, and summaries of measure attributes, are viewed.

3. The generalization of cross-tab which is represented visually is ____________ which is also called as data cube.
a) Two dimensional cube
b) Multidimensional cube
c) N-dimensional cube
d) Cuboid
Answer: a
Explanation: Each cell in the cube is identified for the values for the three dimensional attributes.

4. The process of viewing the cross-tab (Single dimensional) with a fixed value of one attribute is
a) Slicing
b) Dicing
c) Pivoting
d) Both Slicing and Dicing
Answer: a
Explanation: The slice operation selects one particular dimension from a given cube and provides a new sub-cube. Dice selects two or more dimensions from a given cube and provides a new sub-cube.

5. The operation of moving from finer-granularity data to a coarser granularity (by means of aggregation) is called a ________
a) Rollup
b) Drill down
c) Dicing
d) Pivoting
Answer: a
Explanation: The opposite operation—that of moving fromcoarser-granularity data to finer-granularity data—is called a drill down.

6. In SQL the cross-tabs are created using
a) Slice
b) Dice
c) Pivot
d) All of the mentioned
Answer: a
Explanation: Pivot (sum(quantity) for color in (’dark’,’pastel’,’white’)).

7. { (item name, color, clothes size), (item name, color), (item name, clothes size), (color, clothes size), (item name), (color), (clothes size), () }

This can be achieved by using which of the following ?
a) group by rollup
b) group by cubic
c) group by
d) none of the mentioned
Answer: d
Explanation: ‘Group by cube’ is used .

8. What do data warehouses support?
a) OLAP
b) OLTP
c) OLAP and OLTP
d) Operational databases
Answer: a
Explanation: None.

9. SELECT item name, color, clothes SIZE, SUM(quantity)
FROM sales
GROUP BY rollup(item name, color, clothes SIZE);

How many grouping is possible in this rollup?
a) 8
b) 4
c) 2
d) 1
Answer: b
Explanation: { (item name, color, clothes size), (item name, color), (item name), () }.

10. Which one of the following is the right syntax for DECODE?
a) DECODE (search, expression, result [, search, result]… [, default])
b) DECODE (expression, result [, search, result]… [, default], search)
c) DECODE (search, result [, search, result]… [, default], expression)
d) DECODE (expression, search, result [, search, result]… [, default])
Answer: d
Explanation: None.

11.Data scrubbing is which of the Following?
A.A process to reject data from the data warehouse and to create the necessary indexes
B.A process to load the data in the data warehouse and to create the necessary indexes
C.A process to upgrade the quality of data after it is moved into a data warehouse
D.A process to upgrade the quality of data before it is moved into a data warehouse
Answer: Option D
No explanation is given for this question Let’s Discuss on Board

12.The @active data warehouse architecture includes which of the following?
A.At least one data mart
B.Data that can extracted from numerous internal and external sources
C.Near real-time updates
D.All of the above
Answer: Option D
No explanation is given for this question Let’s Discuss on Board

13.A goal of data mining includes which of the folowng?
A.To explain some observed event or condition
B.To confirm that data exists
C.To analyze data for expected relationships
D.To create a new data warehouse
Answer: Option A
No explanation is given for this question Let’s Discuss on Board

14.An operationa system is which of the following?
A.A system that is used to run the business in real time and is based on historical data.
B.A system that is used to run the business in real time and is based on current data.
C.A system that is used to support decision making and is based on current data.
D.A system that is used to support decision making and is based on historical data.
Answer: Option B
No explanation is given for this question Let’s Discuss on Board

15.A data wrehouse is which of the following?
A.Can be updated by end users.
B.Contains numerous naming conventions and formats.
C.Organized around important subject areas.
D.Contains only current data.
Answer: Option C
No explanation is given for this question Let’s Discuss on Board

16. _________ introduces the Management Data Warehouse (MDW) to SQL Server Management Studio for streamlined performance troubleshooting.
a) SQL Server 2005
b) SQL Server 2008
c) SQL Server 2012
d) SQL Server 2014
Answer: b
Explanation: MDW is a set of components that enable a database developer or administrator to quickly track down problems that could be causing performance degradation.

17. Point out the correct statement.
a) MDW consist of three components
b) SQL Server Express instances can be targets
c) Setting up the MDW is a one-step process
d) All of the mentioned
Answer: a
Explanation: MDW consists of three components: Data Collector, MDW database and MDW reports.

18. Which of the following mode allows for the collection and uploading of data to occur on demand?
a) Non-cached mode
b) Cached mode
c) Mixed mode
d) All of the mentioned
Answer: a
Explanation: In non-cached mode, collection and upload are on the same schedule.

19. Which of the following scenario favours cached mode?
a) Continuous collection of data
b) Less frequent uploads
c) Data collection and uploading of jobs on different schedules
d) All of the mentioned
Answer: d
Explanation: Cached mode uses separate schedules for collection and upload.

20. Point out the wrong statement.
a) The Data Collection is performed primarily through SSIS packages that control the collection frequency on the target
b) You should change the database name after creation
c) Do not change any of the job specifications for the data collection and upload jobs
d) None of the mentioned
Answer: b
Explanation: You should not change the database name after creation, because all of the jobs created to manage the database collection refer to the database by the original name and will generate errors if the name is changed.

21. Which of the following is the best Practice and Caveat for Management Data Warehouse?
a) Use a centralized server for the MDW database
b) The XML parameters for a single T-SQL collection item can have multiple <Query> elements
c) Use a distributed server for the MDW database
d) All of the mentioned
Answer: a
Explanation: Centralized server allows you to use a single point for viewing reports for multiple instances.

22. ____________ stores information about how the management data warehouse reports should group and aggregate performance counters.
a) core.snapshots_internal
b) core.supported_collector_types_internal
c) core.wait_categories
d) core.performance_counter_report_group_items
Answer: d
Explanation: core.wait_categories contains the categories used to group wait types according to wait_type characteristic.

23. Which of the following table is used in the management data warehouse schema that is required for the Server Activity?
a) snapshots.query_stat
b) snapshots.os_latch_stats
c) snapshots.active_sessions
d) all of the mentioned
Answer: b
Explanation: snapshots.os_latch_stats is a System level resource table.

24. Which of the following is syntax for sp_add_collector_type procedure?
a) core.sp_add_collector [ @collector_type_uid = ] ‘collector_type_uid’
b) core.sp_add_collector_type [ @collector_type_uid = ].
c) core.sp_add_collector_type [ @collector_type_uid = ] ‘collector_type_uid’
d) none of the mentioned
Answer: c
Explanation: core.sp_add_collector_type adds a new entry to the core.supported_collector_types view in the management data warehouse database.

25. What does collector_type_id stands for in the following code snippet?
core.sp_remove_collector_type [ @collector_type_uid = ] ‘collector_type_uid’
a) uniqueidentifier
b) membership role
c) directory
d) none of the mentioned
Answer: a
Explanation: collector_type_uid is the GUID for the collector type.

26.Which of the following indicates the maximum number of entites that can be involved in a relationship ?
A.Minimum cardinality
B.Maximum cardinality
C.ERD
D.Greater Entity Count (GEC)
Answer: Option B
No explanation is given for this question Let’s Discuss on Board

27.Which type of entity cannot exist in the database unless another type of entity also exists in the database, but does not require that the identifier of that other entity be included as part of its own identifier?
A.Weak entity
B.Strong entity
C.ID-dependent entity
D.ID- independent entity
Answer: Option A
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28.In a one-to-many relationship, the entity that is on the one side of the relationship is called a(n) ________ entity.
A.parent
B.child
C.instance
D.subtype
Answer: Option A
No explanation is given for this question Let’s Discuss on Board

29.Which type of entity represents an actual occurrence of an associated generalized entity?
A.Supertype entity
B.Subtype entity
C.Archetype entity
D.Instance entity
Answer: Option D
No explanation is given for this question Let’s Discuss on Board

30.A recursive relationship is a relationship between an entity and ________ .
A.itself
B.a subtype entity
C.an archetype entity.
D.an instance entity
Answer: Option A
No explanation is given for this question Let’s Discuss on Board.

31) Which is also known as galaxy schema?
A) Star Schema
B) Snow Flake Schema
C) Fact Constellation Schema
D) None of the above
ANSWER: C) Fact Constellation Schema

32) The two primitives, cube definition and dimension definition, can be used for defining the.
A) Data warehouses
B) Data marts
C) Both A & B
D) None of the above
ANSWER: C) Both A & B

33) The following is syntax to define dimension __________
< dimension_name > as ( < attribute_or_dimension_list > )
A) Cube definition
B) Dimension definition
C) Both A & B
D) None of the above
ANSWER: B) Dimension definition

34) List the Schema that a data warehouse system can implement.
A) Star schema
B) Snowflake schema
C) Fact constellation schema
D) All mentioned above
ANSWER: D) All mentioned above

35) How many fact tables are there in a star schema?
A) One
B) Two
C) Three
D) Four
ANSWER: A) One

36) Snowflake schema uses the concept of normalization.
A) True
B) False
ANSWER: A) True

37) Normalization splits up the data into additional tables.
A) Yes
B) No
ANSWER: A) Yes

38) Data Mining Query Language (DMQL) is used for
A) Schema Definition
B) Star Schema Definition
C) Snowflake Schema Definition
D) Fact Constellation Schema Definition
ANSWER: A) Schema Definition

39) DMQL is not based on Structured Query Language (SQL).
A) True
B) False
ANSWER: B) False

40) Data Warehouse OLAP is based on
A) Star Schema
B) Snowflake Schema
C) Fact Constellation Schema
D) All mentioned above
ANSWER: D) All mentioned above

41) Data Warehouse OLAP provides summarized and multidimensional view of data.
A) True
B) False
ANSWER: A) True

42) Some dimension tables in the Snowflake schema are not normalized.
A) True
B) False
ANSWER: B) False

43) Multidimensional schema is defined using.
A) DMQL
B) SQL
C) Both A & B
D) None of the above
ANSWER: A) DMQL

44) Due to normalization in the Snowflake schema, the redundancy is reduced and therefore, it becomes easy to maintain and save the storage space.
A) True
B) False
ANSWER: A) True

45) Is it possible to share dimension tables between fact tables.
A) Yes
B) No
ANSWER: A) Yes

46) A database uses relational model, while a data warehouse uses
A) Star
B) Snowflake
C) Fact Constellation schema
D) All mentioned above
ANSWER: D) All mentioned above

47) Dimensional modelling is used for de-normalizing the
A) ROLAP design
B) MOLAP design
C) Both A & B
D) None of the above
ANSWER: C) Both A & B

48) Abbreviate the term MDS.
A) Master Data Services
B) Minor Data Services
C) Major Data Services
D) Master Data Solutions
ANSWER: A) Master Data Services

49) Cubes are logical representation of multidimensional data.
A) True
B) False
ANSWER: A) True

50) OLAP is the process of analyzing the data, managing aggregations, partitioning information into cubes for in depth visualization.
A) Yes
B) No
ANSWER: A) Yes

51. Data warehouse architecture is based on …………………..
A) DBMS
B) RDBMS
C) Sybase
D) SQL Server
ANSWER:  B

52. …………………….. supports basic OLAP operations, including slice and dice, drill-down, roll-up and pivoting.
A) Information processing
B) Analytical processing
C) Data mining
D) Transaction processing
ANSWER: B

53. The core of the multidimensional model is the ………………….. , which consists of a large set of facts and a number of dimensions.
A) Multidimensional cube
B) Dimensions cube
C) Data cube
D) Data model
ANSWER: C

54. The data from the operational environment enter …………………… of data warehouse.
A) Current detail data
B) Older detail data
C) Lightly Summarized data
D) Highly summarized data
ANSWER: A

55. A data warehouse is ………………….
A) updated by end users.
B) contains numerous naming conventions and formats
C) organized around important subject areas
D) contain only current data
ANSWER: C

56. Business Intelligence and data warehousing is used for …………..
A) Forecasting
B) Data Mining
C) Analysis of large volumes of product sales data
D) All of the above
ANSWER: D

57. Data warehouse contains ……………. data that is never found in the operational environment.
A) normalized
B) informational
C) summary
D) denormalized
ANSWER: C

58. ………………. are responsible for running queries and reports against data warehouse tables.
A) Hardware
B) Software
C) End users
D) Middle ware
ANSWER:  C

59. The biggest drawback of the level indicator in the classic star schema is that is limits ………
A) flexibility
B) quantify
C) qualify
D) ability
ANSWER:  A

60. ……………………….. are designed to overcome any limitations placed on the warehouse by the nature of the relational data model.
A) Operational database
B) Relational database
C) Multidimensional database
D) Data repository
ANSWER:  C

Module 06

1.A definition of a concept is—–if it recognizes all the instances of that concept
A.Complete
B.Consistent
C.Constant
D.None of these
Answer: A
Explanation :Click on Discuss to view users comments.

2:Data mining is
A.The actual discovery phase of a knowledge discovery process
B.The stage of selecting the right data for a KDD process
C.A subject-oriented integrated time variant non-volatile collection of data in support of management
D.None of these
Answer: A
Explanation :Click on Discuss to view users comments.

3:A definition or a concept is————- if it classifies any examples as coming within the concept
A.Complete
B.Consistent
C.Constant
D.None of these
Answer: B
Explanation :Click on Discuss to view users comments.

4:Data selection is
A.The actual discovery phase of a knowledge discovery process
B.The stage of selecting the right data for a KDD process
C.A subject-oriented integrated time variant non-volatile collection of data in support of management
D.None of these
Answer: B
Explanation :Click on Discuss to view users comments.

5:Classification task referred to
A.A subdivision of a set of examples into a number of classes
B.A measure of the accuracy, of the classification of a concept that is given by a certain theory
C.The task of assigning a classification to a set of examples
D.None of these
Answer: C
Explanation :Click on Discuss to view users comments.

6. The log is a sequence of _________ recording all the update activities in the database.
a) Log records
b) Records
c) Entries
d) Redo
Answer: a
Explanation: The most widely used structure for recording database modifications is the log.

7. In the ___________ scheme, a transaction that wants to update the database first creates a complete copy of the database.
a) Shadow copy
b) Shadow Paging
c) Update log records
d) All of the mentioned
Answer: a
Explanation: If at any point the transaction has to be aborted, the system merely deletes the new copy. The old copy of the database has not been affected.

8. The ____________ scheme uses a page table containing pointers to all pages; the page table itself and all updated pages are copied to a new location.
a) Shadow copy
b) Shadow Paging
c) Update log records
d) All of the mentioned
Answer: b
Explanation: Any page which is not updated by a transaction is not copied, but instead the new page table just stores a pointer to the original page.

9. The current copy of the database is identified by a pointer, called ____________ which is stored on disk.
a) Db-pointer
b) Update log
c) Update log records
d) All of the mentioned
Answer: a
Explanation: Any page which is not updated by a transaction is not copied, but instead the new page table just stores a pointer to the original page.

10. If a transaction does not modify the database until it has committed, it is said to use the ___________ technique.
a) Deferred-modification
b) Late-modification
c) Immediate-modification
d) Undo
Answer: a
Explanation: Deferred modification has the overhead that transactions need to make local copies of all updated data items; further, if a transaction reads a data item that it has updated, it must read the value from its local copy.

11. If database modifications occur while the transaction is still active, the transaction is said to use the ___________technique.
a) Deferred-modification
b) Late-modification
c) Immediate-modification
d) Undo
Answer: c
Explanation: We say a transaction modifies the database if it performs an update on a disk buffer, or on the disk itself; updates to the private part of main memory do not count as database modifications.

12. ____________ using a log record sets the data item specified in the log record to the old value.
a) Deferred-modification
b) Late-modification
c) Immediate-modification
d) Undo
Answer: d
Explanation: Undo brings the previous contents.

13. In the __________ phase, the system replays updates of all transactions by scanning the log forward from the last checkpoint.
a) Repeating
b) Redo
c) Replay
d) Undo
Answer: b
Explanation: Undo brings the previous contents.

14. The actions which are played in the order while recording it is called ______________ history.
a) Repeating
b) Redo
c) Replay
d) Undo
Answer: a
Explanation: Undo brings the previous contents.

15. A special redo-only log record < Ti, Xj, V1> is written to the log, where V1 is the value being restored to data item Xj during the rollback. These log records are sometimes called
a) Log records
b) Records
c) Compensation log records
d) Compensation redo records
Answer: c
Explanation: Such records do not need undo information since we never need to undo such an undo operation.

16.Data scrubbing is which of the following?
a.A process to reject data from the data warehouse and to create the necessary indexes
b.A process to load the data in the data warehouse and to create the necessary indexes
c.A process to upgrade the quality of data after it is moved into a data warehouse
d.A process to upgrade the quality of data before it is moved into a data warehouse
Answer: Option D

17.The @active data warehouse architecture includes which of the following?
a.At least one data mart
b.Data that can extracted from numerous internal and external sources
c.Near real-time updates
d.All of the above
Answer: Option D

18.A goal of data mining includes which of the following?
a.To explain some observed event or condition
b.To confirm that data exists
c.To analyze data for expected relationships
d.To create a new data warehouse
Answer: Option A

19.An operational system is which of the following?
a.A system that is used to run the business in real time and is based on historical data.
b.A system that is used to run the business in real time and is based on current data.
c.A system that is used to support decision making and is based on current data.
d.A system that is used to support decision making and is based on historical data.
Answer: Option B

20.__________ contains information that gives users an easy-to-understand perspective of the information stored in the data warehouse
a.Financial metadata
b.Operational metadata
c.Technical metadata
d.Business metadata
Answer: D

21._________ is not associated with data cleaning process.
a.Deduplication
b.Domain consistency
c.Segmentation
d.Disambiguation
Answer: C

22.___________ is a good alternative to the star schema.
a. Star schema.
b. Snowflake schema.
c. Fact constellation.
d. Star-snowflake schema.
Answer: C

23.Dimensionality refers to
a.Cardinality of key values in a star schema
b.The data that describes the transactions in the fact table
c.The level of detail of data that is held in the fact table
d.The level of detail of data that is held in the dimension table
Dimensionality refers to Select one: Cardinality of key values in a star schema The data that describes the transactions in the fact table The level of detail of data that is held in the fact table The level of detail of data that is held in the dimension table
Answer: B

24.A star schema has what type of relationship from a dimension to the fact table?
a.Many-to-many
b.Many-to-one
c.One-to-one
d.One-to-many
Answer: D

25.__________ predicts future trends & behaviors, allowing business managers to make knowledge-driven decisions
a.Meta data
b.Data mart
c.Data warehouse
d.Data Mining
Answer: D

26.Expansion for DSS in DW is
a.Decisive Strategic System
b.Data Support System
c.Data Store System
d.Decision Support system
Answer: D

27.A data warehouse is described by which of the following?
a.Can be updated by end users
b.Contains only current data
c.Contains numerous naming conventions and formats
d.Organized around important subject areas
Answer: D

28.Data in a data warehouse
a.in a flat file format
b.can be normalised but often is not
c.must be in normalised form to at least 3NF
d.must be in normalised form to at least 2NF
Answer: B

29.The main organisational justification for implementing a data warehouse is to provide
a.ETL from operation systems to strategic systems
b.Large scale transaction processing
c.Storing large volumes of data
d.Decision support
Answer: D

30.A data warehouse
a.must import data from transactional systems whenever significant changes occur in the transactional data
b.works on live transactional data to provide up to date and valid results
c.takes regular copies of transaction data
d.takes preprocessed transaction data and stores in a way that is optimised for analysis
Answer: D

31.Data warehouse contains ________data that is seldom found in the operational environment
a.informational
b.normalized
c.denormalized
d.summary
Answer: D

32.Which of the following statements about DW is true?
a.A data warehouse is necessary to all those organisations that are using relational OLTP
b.A data warehouse is useful to all organisations that currently use OLTP
c.A data warehouse is valuable to the organisations that need to keep an audit trail of their activities
d.A data warehouse is valuable only if the organisation has an interest in analysing historical data
Answer: D

33.What is true of storing data in DW?
a.A DW automatically makes a copy of every transaction recorded in OLTP systems
b.Adding data for the sake of it may well degrade the effectiveness of DW
c.A DW is a relatively straighttforward thing to set up
d.The more data a data warehouse has, the better it is
Answer: B

34.The extract process is _______
a.capturing a subset of the data contained in operational systems
b.capturing a subset of the data contained in various decision support systems
c.capturing all of the data contained in various decision support systems
d.capturing of the data contained in all operational systems
Answer: A

35.Which statement best describes fact table
a.A fact table describes the transactions stored in a DW
b.The fact table of a DW is the main store of descriptions of the transactions
c.A fact table describes the granularity of data in a DW
d.The fact table of a data warehouse is the main store of all of the recorded transactions over time
Answer: D

36.Fact tables are described by which of the following?
a.Partially normalized
b.Completely denormalized
c.Partially denormalized
d.Completely normalized
Answer: D

37._______ are numeric measurements or values that represent a specific business aspect or activity
a.Dimensions
b.Schemas
c.Facts
d.Tables
Answer: C

38.A fact is said to be fully additive if __________.
a.additive over atleast one of the dimensions
b.Only numeric measures are used
c.All possible summaries are stored
d.it is additive over every dimension of its dimensionality
Answer: D

39.Granularity refers to
a.The level of detail of the data stored in a data warehouse
b.The number of fact tables in a data warehouse
c.The number of dimensions in a data warehouse
d.The level of detail of the data descriptions held in a data warehouse
Answer: A

40.Data cubes can grow to n-number of dimensions, thus becoming _______
a.Hypercubes
b.Star Cubes
c.Dimensional Cubes
d.Solid cubes
Answer: A

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