Chapter 10 Flashcards

1
Q

Most real-world database transactions are formed by only one database request.

A

false

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2
Q

The DBMS guarantees that the semantic meaning of a transaction truly represents the real-world event.

A

false

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3
Q

Atomicity indicates the permanence of the database’s consistent state.

A

false

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4
Q

The multiuser DBMS must implement controls to ensure serializability and isolation of transactions, in addition to atomicity and durability, in order to guard the database’s consistency and integrity.

A

true

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5
Q

Durability requires that all portions of the transaction must be treated as a single, logical unit of work in which all operations are applied and completed to produce a consistent database.

A

false

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6
Q

In a page-level lock, the DBMS will lock an entire diskpage.

A

true

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7
Q

A shared lock produces no conflict as long as all the concurrent transactions are read-write only.

A

false

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8
Q

When using an optimistic approach, a transaction reads the database, executes the needed computations, and makes the updates to a private copy of the database values.

A

true

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9
Q

An optimistic approach is based on the assumption that the majority of the database operations do not conflict.

A

true

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10
Q

The last step in the write-through technique recovery procedure is to identify the last checkpoint in the transaction log.

A

false

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11
Q

A transaction is a ____ unit of work that must be either entirely completed or aborted.

A

timed

practical

-logical

physical

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12
Q

____ means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.

A

Serializability

Atomicity

-Isolation

Time stamping

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13
Q

All transactions must display ____.

A

atomicity, consistency, and durability

durability and isolation

consistency, durability, and isolation

-atomicity, durability, consistency, and isolation

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14
Q

ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a COMMIT?

A

Five SQL statements are executed.

-The end of a program is successfully reached.

The program is abnormally terminated.

The database is shut down for maintenance.

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15
Q

ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a ROLLBACK?

A

Five SQL statements are executed.

The end of a program is successfully reached.

-The program is abnormally terminated.

The database is shut down for maintenance.

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16
Q

One of the three most common data integrity and consistency problems is ____.

A

-lost updates

disk failures

user errors

deadlocks

17
Q

As long as two transactions, T1 and T2, access ____ data, there is no conflict, and the order of execution is irrelevant to the final outcome.

A

shared

common

-unrelated

locked

18
Q

The ____ manager is responsible for assigning and policing the locks used by the transactions.

A

transaction

database

-lock

schedule

19
Q

Lock ____ indicates the level of lock use.

A

-granularity

shrinking

growing

serializability

20
Q

A diskpage, or page, is the equivalent of a ____.

A

database table

disk sector

database schema

-diskblock

21
Q

A ____ lock allows concurrent transactions to access different rows of the same table.

A

database-level

table-level

page-level

-row-level

22
Q

A(n) ____ lock exists when concurrent transactions are granted read access on the basis of a common lock.

A

-shared

exclusive

binary

two-phase

23
Q

What is a rule that applies to the two-phase locking protocol?

A

-Two transactions cannot have conflicting locks.

No unlock operation can precede a lock operation in a different transaction.

No data is affected until all locks are released.

No data is affected until the transaction is in its locked position.

24
Q

The ____ approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.

A

scheduled

table-locking

unique

-timestamping

25
Although the DBMS is designed to recover a database to a previous consistent state when an interruption prevents the completion of a required set of transactions, the transactions themselves are defined by the end user or programmer and must be semantically correct.
true
26
Atomicity indicates the permanence of the database's consistent state.
false
27
Incomplete or improper transactions can have a devastating effect on database integrity.
true
28
The scheduler establishes the order in which the operations within concurrent transactions are executed.
true
29
A shared lock produces no conflict as long as all the concurrent transactions are read-write only.
false
30
A growing phase in a two-phase lock is when a transaction acquires all the required locks without locking any data.
false
31
____ requires that all operations of a transaction be completed.
Specificity -Atomicity Durability Time stamping
32
The ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements: ____ and ROLLBACK.
RETRIEVE ASSIGN UPDATE -COMMIT
33
The information stored in the ____ is used by the DBMS for a recovery requirement triggered by a ROLLBACK statement, a program’s abnormal termination, or a system failure such as a network discrepancy or a disk crash.
data dictionary metadata rollback manager -transaction log
34
As long as two transactions, T1 and T2, access ____ data, there is no conflict, and the order of execution is irrelevant to the final outcome.
shared common -unrelated locked
35
____ are required to prevent another transaction from reading inconsistent data.
-Locks Schedules Stamps Logs
36
A ____ lock locks the entire diskpage.
transaction-level table-level -page-level row-level
37
A ____ lock allows concurrent transactions to access different rows of the same table.
database-level table-level page-level -row-level
38
A(n) ____ specifically reserves access to the transaction that locked the object.
shared lock -exclusive lock binary lock deadlock
39
A(n) ____ condition occurs when two or more transactions wait for each other to unlock data.
-deadlock exclusive lock binary lock two-phase lock