23909197
Beschreibung
Quiz von Craig Willey, aktualisiert more than 1 year ago
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Erstellt von Craig Willey
vor etwa 4 Jahre
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Frage 1
Frage
All transaction properties must display ____
Antworten
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atomicity, serializability, and durability
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durability and isolation
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serializability, durability, and isolation
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atomicity, durability, serializability, and isolation
Frage 2
Frage
A ____ lock prevents the use of any tables in the database from one transaction while another transaction is being processed
Antworten
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database-level
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table-level
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page-level
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row-level
Frage 3
Frage
A ____ lock locks the entire table preventing access to any row by a transaction while another transaction is using the table.
Antworten
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database-level
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table-level
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page-level
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row-level
Frage 4
Frage
A ____ lock locks the entire diskpage.
Antworten
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transaction-level
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table-level
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page-level
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row-level
Frage 5
Frage
A ____ lock allows concurrent transactions to access different rows of the same table.
Antworten
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database-level
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table-level
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page-level
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row-level
Frage 6
Frage
A(n) ____ lock has only two stages (0 & 1).
Antworten
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shared
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exclusive
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binary
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two-phase
Frage 7
Frage
A(n) ____ specifically reserves access to the transaction that locked the object.
Antworten
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shared lock
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exclusive lock
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binary lock
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deadlock
Frage 8
Frage
A(n) ____ lock exists when concurrent transactions are granted read access on the basis of a common lock.
Antworten
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shared
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exclusive
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binary
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two-phase
Frage 9
Frage
A(n) ____ lock defines how transactions acquire and relinquish locks.
Antworten
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shared
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exclusive
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binary
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two-phase
Frage 10
Frage
A(n) ____ condition occurs when two transactions wait for each other to unlock data.
Antworten
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deadlock
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exclusive lock
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binary lock
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two-phase lock
Frage 11
Frage
Which of the following rules applies to the two-phase locking protocol?
Antworten
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Two transactions cannot have conflicting locks.
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No unlock operation can precede a lock operation in a different transaction.
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No data is affected until all locks are released.
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No data is affected until the transaction is in its locked position.
Frage 12
Frage
____ control is the management of concurrent transaction execution.
Antworten
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Concurrency
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Lock
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Transaction
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Database
Frage 13
Frage
The most common algorithms for concurrency control are locks, ____ stamping, and optimistic methods.
Antworten
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date
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time
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hour
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minute
Frage 14
Frage
____ requires that all operations of a transaction be completed.
Antworten
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Specificity
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Atomicity
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Durability
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Time stamping
Frage 15
Frage
____ means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.
Antworten
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Serializability
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Atomicity
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Isolation
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Time stamping
Frage 16
Frage
When you read from and/or write to a database, you have created a(n) ____.
Antworten
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transaction
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back up
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update
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queue
Frage 17
Frage
A transaction is a ____ unit of work that must be either entirely completed or aborted.
Antworten
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timed
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practical
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logical
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physical
Frage 18
Frage
The ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements: ____ and ROLLBACK.
Antworten
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RETRIEVE
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ASSIGN
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UPDATE
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COMMIT
Frage 19
Frage
The ____ establishes the order in which the operations within concurrent transactions are executed.
Antworten
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transaction log
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timer
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lock manager
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scheduler
Frage 20
Frage
The ____ manager is responsible for assigning and policing the locks used by the transactions.
Antworten
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transaction
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database
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lock
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schedule
Frage 21
Frage
Lock ____ indicates the level of lock use.
Antworten
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granularity
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shrinking
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growing
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serializability
Frage 22
Frage
During the ____ phase, the transaction scans the database, executes the needed computations, and makes the updates to a private copy of the database values.
Antworten
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read
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validation
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write
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shared
Frage 23
Frage
During the ____ phase, the changes are permanently applied to the database.
Antworten
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read
-
validation
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write
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shared
Frage 24
Frage
During the ____ phase, the changes are permanently applied to the database.
Antworten
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read
-
validation
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write
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shared
Frage 25
Frage
A(n) ____ backup of the data is when only the last modifications done to the database are copied.
Antworten
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differential
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complete
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partial
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incomplete
Frage 26
Frage
A transaction that changes the contents of the database must alter the database from one ____ state to another.
Antworten
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consistent
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dependent
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independent
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inconsistent
Frage 27
Frage
When is the implicit beginning of a transaction?
Antworten
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When the database is started
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When a table is accessed for the first time
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When the first SQL statement is encountered
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When the COMMIT command is issued
Frage 28
Frage
A(n) ____ phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.
Antworten
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growing
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shrinking
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locking
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unlocking
Frage 29
Frage
The ____ approach is based on the assumption that the majority of the database operations do not conflict.
Antworten
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default
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basic
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scheduled
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optimistic
Frage 30
Frage
A diskpage, or page, is the equivalent of a ____.
Antworten
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database table
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disk sector
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database schema
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diskblock
Frage 31
Frage
The ____ is responsible for assigning and policing the locks used by the transactions.
Antworten
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lock manager
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scheduler
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DBA
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transaction log
Frage 32
Frage
What is a consistent database?
Antworten
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One in which all tables have foreign keys
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One in which all data integrity constraints are satisfied
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One in which all tables are normalized
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One in which all SQL statements only update one table at a time
Frage 33
Frage
A transaction acquires a ____ prior to data access.
Antworten
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grain
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timestamp
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lock
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key
Frage 34
Frage
Changes are permanently applied to the database during the ____ phase of a transaction.
Antworten
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commit
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write
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input
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output
Frage 35
Frage
The ____ approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.
Antworten
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scheduled
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table-locking
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unique
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time-stamping
Frage 36
Frage
All transactions are controlled and executed by the ____ to guarantee database integrity.
Antworten
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scheduler
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DBMS
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transaction log
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DBA
Frage 37
Frage
You can define ____ to help the DBMS ensure that the database remains in a consistent state.
Antworten
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integrity constraints
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business rules
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lock-level transactions
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stored procedures
Frage 38
Frage
By its nature, a single-user database system automatically ensures ____ of the database, because only one transaction is executed at a time.
Antworten
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serializability and durability
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atomicity and isolation
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serializability and isolation
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atomicity and serializability
Frage 39
Frage
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.
Antworten
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data dictionary
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metadata
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rollback manager
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transaction log
Frage 40
Frage
Which of the following is NOT stored in the transaction log?
Antworten
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The type of operation performed
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A record for the beginning of a transaction
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The name of the table
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The number of affected records
Frage 41
Frage
What is one of the three most common data integrity and consistency problems?
Antworten
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Lost updates
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Disk failures
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User errors
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Deadlocks
Frage 42
Frage
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.
Antworten
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lost updates
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uncommitted data
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transaction failure
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inconsistent retrieval
Frage 43
Frage
____ occur when a transaction calculates some summary (aggregate) functions over a set of data while other transactions are updating the data.
Antworten
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Lost updates
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Uncommitted data
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Transaction failures
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Inconsistent retrievals
Frage 44
Frage
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.
Antworten
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shared
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common
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unrelated
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locked
Frage 45
Frage
The scheduler facilitates data ____ to ensure that two transactions do not update the same data element at the same time.
Antworten
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durability
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isolation
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atomicity
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serializability
Frage 46
Frage
What is the most restrictive lock granularity?
Antworten
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Database
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Table
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Page
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Row
Frage 47
Frage
Which lock granularity has the highest overhead?
Antworten
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Database
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Table
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Row
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Field
Frage 48
Frage
A ____ lock has only two states.
Antworten
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shared
-
binary
-
database
-
row-level
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