Questão 1
Questão
All transaction properties must display ____
Responda
-
atomicity, serializability, and durability
-
durability and isolation
-
serializability, durability, and isolation
-
atomicity, durability, serializability, and isolation
Questão 2
Questão
A ____ lock prevents the use of any tables in the database from one transaction while another transaction is being processed
Responda
-
database-level
-
table-level
-
page-level
-
row-level
Questão 3
Questão
A ____ lock locks the entire table preventing access to any row by a transaction while another transaction is using the table.
Responda
-
database-level
-
table-level
-
page-level
-
row-level
Questão 4
Questão
A ____ lock locks the entire diskpage.
Responda
-
transaction-level
-
table-level
-
page-level
-
row-level
Questão 5
Questão
A ____ lock allows concurrent transactions to access different rows of the same table.
Responda
-
database-level
-
table-level
-
page-level
-
row-level
Questão 6
Questão
A(n) ____ lock has only two stages (0 & 1).
Responda
-
shared
-
exclusive
-
binary
-
two-phase
Questão 7
Questão
A(n) ____ specifically reserves access to the transaction that locked the object.
Responda
-
shared lock
-
exclusive lock
-
binary lock
-
deadlock
Questão 8
Questão
A(n) ____ lock exists when concurrent transactions are granted read access on the basis of a common lock.
Responda
-
shared
-
exclusive
-
binary
-
two-phase
Questão 9
Questão
A(n) ____ lock defines how transactions acquire and relinquish locks.
Responda
-
shared
-
exclusive
-
binary
-
two-phase
Questão 10
Questão
A(n) ____ condition occurs when two transactions wait for each other to unlock data.
Responda
-
deadlock
-
exclusive lock
-
binary lock
-
two-phase lock
Questão 11
Questão
Which of the following rules applies to the two-phase locking protocol?
Responda
-
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.
Questão 12
Questão
____ control is the management of concurrent transaction execution.
Responda
-
Concurrency
-
Lock
-
Transaction
-
Database
Questão 13
Questão
The most common algorithms for concurrency control are locks, ____ stamping, and optimistic methods.
Questão 14
Questão
____ requires that all operations of a transaction be completed.
Responda
-
Specificity
-
Atomicity
-
Durability
-
Time stamping
Questão 15
Questão
____ means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.
Responda
-
Serializability
-
Atomicity
-
Isolation
-
Time stamping
Questão 16
Questão
When you read from and/or write to a database, you have created a(n) ____.
Responda
-
transaction
-
back up
-
update
-
queue
Questão 17
Questão
A transaction is a ____ unit of work that must be either entirely completed or aborted.
Responda
-
timed
-
practical
-
logical
-
physical
Questão 18
Questão
The ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements: ____ and ROLLBACK.
Responda
-
RETRIEVE
-
ASSIGN
-
UPDATE
-
COMMIT
Questão 19
Questão
The ____ establishes the order in which the operations within concurrent transactions are executed.
Responda
-
transaction log
-
timer
-
lock manager
-
scheduler
Questão 20
Questão
The ____ manager is responsible for assigning and policing the locks used by the transactions.
Responda
-
transaction
-
database
-
lock
-
schedule
Questão 21
Questão
Lock ____ indicates the level of lock use.
Responda
-
granularity
-
shrinking
-
growing
-
serializability
Questão 22
Questão
During the ____ phase, the transaction scans the database, executes the needed computations, and makes the updates to a private copy of the database values.
Responda
-
read
-
validation
-
write
-
shared
Questão 23
Questão
During the ____ phase, the changes are permanently applied to the database.
Responda
-
read
-
validation
-
write
-
shared
Questão 24
Questão
During the ____ phase, the changes are permanently applied to the database.
Responda
-
read
-
validation
-
write
-
shared
Questão 25
Questão
A(n) ____ backup of the data is when only the last modifications done to the database are copied.
Responda
-
differential
-
complete
-
partial
-
incomplete
Questão 26
Questão
A transaction that changes the contents of the database must alter the database from one ____ state to another.
Responda
-
consistent
-
dependent
-
independent
-
inconsistent
Questão 27
Questão
When is the implicit beginning of a transaction?
Responda
-
When the database is started
-
When a table is accessed for the first time
-
When the first SQL statement is encountered
-
When the COMMIT command is issued
Questão 28
Questão
A(n) ____ phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.
Responda
-
growing
-
shrinking
-
locking
-
unlocking
Questão 29
Questão
The ____ approach is based on the assumption that the majority of the database operations do not conflict.
Responda
-
default
-
basic
-
scheduled
-
optimistic
Questão 30
Questão
A diskpage, or page, is the equivalent of a ____.
Responda
-
database table
-
disk sector
-
database schema
-
diskblock
Questão 31
Questão
The ____ is responsible for assigning and policing the locks used by the transactions.
Responda
-
lock manager
-
scheduler
-
DBA
-
transaction log
Questão 32
Questão
What is a consistent database?
Responda
-
One in which all tables have foreign keys
-
One in which all data integrity constraints are satisfied
-
One in which all tables are normalized
-
One in which all SQL statements only update one table at a time
Questão 33
Questão
A transaction acquires a ____ prior to data access.
Questão 34
Questão
Changes are permanently applied to the database during the ____ phase of a transaction.
Responda
-
commit
-
write
-
input
-
output
Questão 35
Questão
The ____ approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.
Responda
-
scheduled
-
table-locking
-
unique
-
time-stamping
Questão 36
Questão
All transactions are controlled and executed by the ____ to guarantee database integrity.
Responda
-
scheduler
-
DBMS
-
transaction log
-
DBA
Questão 37
Questão
You can define ____ to help the DBMS ensure that the database remains in a consistent state.
Responda
-
integrity constraints
-
business rules
-
lock-level transactions
-
stored procedures
Questão 38
Questão
By its nature, a single-user database system automatically ensures ____ of the database, because only one transaction is executed at a time.
Responda
-
serializability and durability
-
atomicity and isolation
-
serializability and isolation
-
atomicity and serializability
Questão 39
Questão
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.
Responda
-
data dictionary
-
metadata
-
rollback manager
-
transaction log
Questão 40
Questão
Which of the following is NOT stored in the transaction log?
Responda
-
The type of operation performed
-
A record for the beginning of a transaction
-
The name of the table
-
The number of affected records
Questão 41
Questão
What is one of the three most common data integrity and consistency problems?
Responda
-
Lost updates
-
Disk failures
-
User errors
-
Deadlocks
Questão 42
Questão
The phenomenon of ____ occurs when two transactions, T1 and T2, are executed concurrently and the first transaction (T1) is rolled back after the second transaction (T2) has already accessed the uncommitted data—thus violating the isolation property of transactions.
Responda
-
lost updates
-
uncommitted data
-
transaction failure
-
inconsistent retrieval
Questão 43
Questão
____ occur when a transaction calculates some summary (aggregate) functions over a set of data while other transactions are updating the data.
Responda
-
Lost updates
-
Uncommitted data
-
Transaction failures
-
Inconsistent retrievals
Questão 44
Questão
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.
Responda
-
shared
-
common
-
unrelated
-
locked
Questão 45
Questão
The scheduler facilitates data ____ to ensure that two transactions do not update the same data element at the same time.
Responda
-
durability
-
isolation
-
atomicity
-
serializability
Questão 46
Questão
What is the most restrictive lock granularity?
Questão 47
Questão
Which lock granularity has the highest overhead?
Questão 48
Questão
A ____ lock has only two states.
Responda
-
shared
-
binary
-
database
-
row-level