1410+ DataBase Management System (DBMS) Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Computer Science Engineering (CSE) , Bachelor of Science in Computer Science FY (BSc CS) , Bachelor of Science in Computer Science SY (BSc CS) , Bachelor of Science in Information Technology SY (BSc IT) , Bachelor of Computer Applications (BCA) .

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901.	A non-correlated subquery can be deﬁned as
A.	a set of sequential queries, all of which must always return a single value
B.	a set of sequential queries, all of which must return values from the same table
C.	a select statement that can be embedded in a clause of another select statement only
D.	a set of one or more sequential queries in which generally the result of the inner query is used as the search value in the outer query
Answer» D. a set of one or more sequential queries in which generally the result of the inner query is used as the search value in the outer query

902.	Which statement is true regarding synonyms?
A.	synonyms can be created for tables but not views
B.	synonyms are used to reference only those tables that are owned by another user
C.	a public synonym and a private synonym can exist with the same name for the same table
D.	the drop synonym statement removes the synonym, and the status of the table on which the synonym has been created becomes invalid
Answer» C. a public synonym and a private synonym can exist with the same name for the same table

903.	The method of access that uses key transformation is called as
A.	direct
B.	hash
C.	random
D.	sequential
Answer» B. hash

904.	Why do we need concurrency control on B+ trees ?
A.	to remove the unwanted data
B.	to easily add the index elements
C.	to maintain accuracy of index
D.	all of the mentioned
Answer» C. to maintain accuracy of index

905.	How many techniques are available to control concurrency on B+ trees?
A.	one
B.	three
C.	four
D.	none of the mentioned
Answer» D. none of the mentioned

906.	In crabbing protocol locking
A.	goes down the tree and back up
B.	goes up the tree and back down
C.	goes down the tree and releases
D.	goes up the tree and releases
Answer» A. goes down the tree and back up

907.	The deadlock can be handled by
A.	removing the nodes that are deadlocked
B.	restarting the search after releasing the lock
C.	restarting the search without releasing the lock
D.	resuming the search
Answer» B. restarting the search after releasing the lock

908.	In crabbing protocol, the lock obtained on the root node is in mode.
A.	shared
B.	exclusive
C.	read only
D.	none of the mentioned
Answer» A. shared

909.	If needed to split a node or coalesce it with its siblings, or redistribute key values between siblings, the crabbing protocol locks the parent of the node in mode.
A.	shared
B.	exclusive
C.	read only
D.	none of the mentioned
Answer» B. exclusive

910.	Instead of locking index leaf nodes in a two-phase manner, some index concurrency- control schemes use on individual key values, allowing other key values to be inserted or deleted from the same leaf.
A.	b+ tree locking
B.	link level locking
C.	key-value locking
D.	next value locking
Answer» C. key-value locking

911.	The recovery scheme must also provide
A.	high availability
B.	low availability
C.	high reliability
D.	high durability
Answer» A. high availability

912.	Which one of the following is a failure to a system
A.	boot crash
B.	read failure
C.	transaction failure
D.	all of the mentioned
Answer» C. transaction failure

913.	The system has entered an undesirable state (for example, deadlock), as a result of which a transaction cannot continue with its normal execution. This is
A.	read error
B.	boot error
C.	logical error
D.	system error
Answer» C. logical error

914.	The transaction can no longer continue with its normal execution because of some internal condition, such as bad input, data not found, overﬂow, or resource limit exceeded. This is
A.	read error
B.	boot error
C.	logical error
D.	system error
Answer» C. logical error

915.	The assumption that hardware errors and bugs in the software bring the system to a halt, but do not corrupt the nonvolatile storage contents, is known as the
A.	stop assumption
B.	fail assumption
C.	halt assumption
D.	fail-stop assumption
Answer» D. fail-stop assumption

916.	The database is partitioned into ﬁxed- length storage units called
A.	parts
B.	blocks
C.	reads
D.	build
Answer» B. blocks

917.	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. log records

918.	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. shadow copy

919.	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. shadow paging

920.	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. deferred-modiﬁcation

921.	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. undo

922.	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. redo

923.	The actions which are played in the order while recording it is called history.
A.	repeating
B.	redo
C.	replay
D.	undo
Answer» A. repeating

924.	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. compensation log records

925.	In order to reduce the overhead in retrieving the records from the storage space we use
A.	logs
B.	log buﬀer
C.	medieval space
D.	lower records
Answer» B. log buﬀer

1410+ DataBase Management System (DBMS) Solved MCQs

A non-correlated subquery can be deﬁned as

Which statement is true regarding synonyms?

The method of access that uses key transformation is called as

Why do we need concurrency control on B+ trees ?

How many techniques are available to control concurrency on B+ trees?

In crabbing protocol locking

The deadlock can be handled by

In crabbing protocol, the lock obtained on the root node is in mode.

If needed to split a node or coalesce it with its siblings, or redistribute key values between siblings, the crabbing protocol locks the parent of the node in mode.

Instead of locking index leaf nodes in a two-phase manner, some index concurrency- control schemes use on individual key values, allowing other key values to be inserted or deleted from the same leaf.

The recovery scheme must also provide

Which one of the following is a failure to a system

The system has entered an undesirable state (for example, deadlock), as a result of which a transaction cannot continue with its normal execution. This is

The transaction can no longer continue with its normal execution because of some internal condition, such as bad input, data not found, overﬂow, or resource limit exceeded. This is

The assumption that hardware errors and bugs in the software bring the system to a halt, but do not corrupt the nonvolatile storage contents, is known as the

The database is partitioned into ﬁxed- length storage units called

The log is a sequence of recording all the update activities in the database.

In the scheme, a transaction that wants to update the database ﬁrst creates a complete copy of the database.

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.

If a transaction does not modify the database until it has committed, it is said to use the technique.

using a log record sets the data item speciﬁed in the log record to the old value.

In the phase, the system replays updates of all transactions by scanning the log forward from the last checkpoint.

The actions which are played in the order while recording it is called history.

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

In order to reduce the overhead in retrieving the records from the storage space we use

Writing the buﬀered log to is sometimes referred to as a log force.

The policy, allows a transaction to commit even if it has modiﬁed some blocks that have not yet been written back to disk.

policy allows multiple updates to accumulate on a block before it is output to stable storage, which can reduce the number of output operations greatly for frequently updated blocks.

The policy, allows the system to write modiﬁed blocks to disk even if the transactions that made those modiﬁcations have not all committed.

The contains a list of blocks that have been updated in the database buﬀer.

The silicon chips used for data processing are called

Which of the following is used for manufacturing chips?

What was the name of the ﬁrst commercially available microprocessor chip?

The magnetic storage chip used to provide non-volatile direct access storage of data and that have no moving parts are known as

The ALU of a computer normally contains a number of high speed storage element called

A dump of the database contents is also referred to as an dump.

dump, writes out SQL DDL statements and SQL insert statements to a ﬁle, which can then be reexecuted to re- create the database.

dump schemes have been developed that allow transactions to be active while the dump is in progress.

ARIES uses a to identify log records, and stores it in database pages.

ARIES supports operations, which are physical in that the aﬀected page is physically identiﬁed, but can be logical within the page.

is used to minimize unnecessary redos during recovery.

scheme that records only information about dirty pages and associated information and does not even require of writing dirty pages to disk.

Whenever an update operation occurs on a page, the operation stores the LSN of its log record in the ﬁeld of the page.

The contains a list of pages that have been updated in the database buﬀer.

determines which transactions to undo, which pages were dirty at the time of the crash, and the LSN from which the redo pass should start.

starts from a position determined during analysis, and performs a redo, repeating history, to bring the database to a state it was in before the crash.

rolls back all transactions that were incomplete at the time of crash.

Which lock should be obtained to prevent a concurrent transaction from executing a conﬂicting read, insert or delete operation on the same key value.

Once the lower-level lock is released, the operation cannot be undone by using the old values of updated data items, and must instead be undone by executing a compensating operation; such an operation is called

Which of the following is used for undo operations alone?

926.	Writing the buﬀered log to is sometimes referred to as a log force.
A.	memory
B.	backup
C.	redo memory
D.	disk
Answer» D. disk

927.	The policy, allows a transaction to commit even if it has modiﬁed some blocks that have not yet been written back to disk.
A.	force
B.	no-force
C.	steal
D.	no-steal
Answer» B. no-force

928.	policy allows multiple updates to accumulate on a block before it is output to stable storage, which can reduce the number of output operations greatly for frequently updated blocks.
A.	force
B.	no-force
C.	steal
D.	no-steal
Answer» B. no-force

929.	The policy, allows the system to write modiﬁed blocks to disk even if the transactions that made those modiﬁcations have not all committed.
A.	force
B.	no-force
C.	steal
D.	no-steal
Answer» C. steal

930.	The contains a list of blocks that have been updated in the database buﬀer.
A.	latches
B.	swap space
C.	dirty block
D.	none of the mentioned
Answer» C. dirty block

931.	The silicon chips used for data processing are called
A.	ram chips
B.	rom chips
C.	micro processors
D.	prom chips
Answer» D. prom chips

932.	Which of the following is used for manufacturing chips?
A.	control bus
B.	control unit
C.	parity unit
D.	semiconductor
Answer» D. semiconductor

933.	What was the name of the ﬁrst commercially available microprocessor chip?
A.	intel 308
B.	intel 33
C.	intel 4004
D.	motorola 639
Answer» C. intel 4004

934.	The magnetic storage chip used to provide non-volatile direct access storage of data and that have no moving parts are known as
A.	magnetic core memory
B.	magnetic tape memory
C.	magnetic disk memory
D.	magnetic bubble memory
Answer» D. magnetic bubble memory

935.	The ALU of a computer normally contains a number of high speed storage element called
A.	semiconductor memory
B.	registers
C.	hard disks
D.	magnetic disk
Answer» B. registers