单选题One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()A uses undo data for roll forwardB uses Flashback Log for recoveryC uses online redo logs to roll backD uses undo data to ro

题目
单选题
One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()
A

uses undo data for roll forward

B

uses Flashback Log for recovery

C

uses online redo logs to roll back

D

uses undo data to roll back the transaction

E

uses Recovery Manager (RMAN) to roll back

F

uses the System Monitor (SMON) background process to perform instance recovery


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更多“单选题One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()A uses undo data for roll forwardB uses Flashback Log for recoveryC uses online redo logs to roll backD uses undo data to ro”相关问题
  • 第1题:

    You can use Oracle Flashback to look at past activity in your database. What are two other characteristics of Oracle Flashback?()

    • A、Oracle Flashback uses undo information to construct consistent data. 
    • B、You can use a cursor opened while using an Oracle Flashback image to perform DML once you deactivate Oracle Flashback in your session. 
    • C、You can only use Oracle Flashback view of the data if the required records are still in the online redo log files. 
    • D、Oracle Flashback lists the DML that was executed during the period you identify when initiating your session. 

    正确答案:A,B

  • 第2题:

    What advantage would you get if you increase the length of time during which the undo information would be stored in the database?()

    • A、roll back of large transactions
    • B、roll forward to redo a transaction
    • C、data concurrency for large updates
    • D、read consistency for long-running transactions

    正确答案:D

  • 第3题:

    In a situation where no multiplexing of redo logs takes place, what happens when Oracle cannot read data from the online redo log group for archiving?()

    • A、Nothing happens
    • B、Oracle will automatically switch redo logs when detected 
    • C、Oracle eventually won't allow new records to be added to the database 
    • D、The instance crashes

    正确答案:C

  • 第4题:

    The user SCOTT executes the following command successfully to increase the salary values in one of his sessions:  SQL> UPDATE emp SET sal=sal*1.15 WHERE deptno=20;  Before SCOTT ends the transaction, user HR who has the privileges on EMP table executes a query to fetch the salary details but finds the old salary values instead of the increased values. Why does HR still see the old data?()

    • A、because of redo data from redo log file
    • B、because of data from database buffer cache
    • C、because of data from a temporary tablespace
    • D、because of undo data from the undo tablespace

    正确答案:D

  • 第5题:

    Which two statements about Flashback Query are true?()

    • A、It is generated by using the redo log files. 
    • B、It helps in row-level recovery from user errors.
    • C、It can be performed to recover ALTER TABLE statements 
    • D、It fails when undo data pertaining to the transaction is overwritten.
    • E、The database has to be opened with the resetlogs option after performing Flashback Query.

    正确答案:B,D

  • 第6题:

    Which three statements are true about database recovery operations?()

    • A、Damaged or lost data files are restored from backups.
    • B、Redo log file entries are used to roll forward the database.
    • C、Undo segments are used to roll back any uncommitted transactions.
    • D、Transactions that were active when the failure occurred are restarted.
    • E、Transactions that were active when the failure occurred are automatically committed during the recover procedure.

    正确答案:A,B,C

  • 第7题:

    单选题
    One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()
    A

    uses undo data for roll forward

    B

    uses Flashback Log for recovery

    C

    uses online redo logs to roll back

    D

    uses undo data to roll back the transaction

    E

    uses Recovery Manager (RMAN) to roll back

    F

    uses the System Monitor (SMON) background process to perform instance recovery


    正确答案: F
    解析: 暂无解析

  • 第8题:

    单选题
    What does the DB_FLASHBACK_RETENTION_TARGET parameter configure?()
    A

     An upper limit on how far you can flash back the database,depending on the information in the redo logs

    B

     An upper limit on how far you can flash back the database,depending on the information in the undo tablespace

    C

     The amount of time for which the flashback data is to be kept in the flash recovery area, provided that there is enough space

    D

     The amount of time for which the flashback data is guaranteed to be kept in the undo tablespace,provided that there is enough space


    正确答案: B
    解析: 暂无解析

  • 第9题:

    单选题
    In a situation where no multiplexing of redo logs takes place, what happens when Oracle cannot read data from the online redo log group for archiving?()
    A

    Nothing happens

    B

    Oracle will automatically switch redo logs when detected 

    C

    Oracle eventually won't allow new records to be added to the database 

    D

    The instance crashes


    正确答案: C
    解析: 暂无解析

  • 第10题:

    单选题
    You are maintaining your database in Oracle10g. You set the value of the UNDO_RETENTION initialization parameter to zero in the initialization parameter file. What will be the impact of specifying this setting?()
    A

     The database will not start.

    B

     The database will start but will not retain the undo data in the undo segment.

    C

     The database will start, and the undo segment will contain the undo data for at least one hour.

    D

     The database will start, and the undo segment will retain the undo data for at least 15 minutes.


    正确答案: B
    解析: 暂无解析

  • 第11题:

    多选题
    You set the undo pool resource plan directive for the consumer group named DSS_USERS that is assigned to the DAY_SHIFT plan. The database users, SCOTT and BLAKE, belong to the DSS_USERS resource group. The user, SCOTT, initiates a database session and executes a batch operation that inserts millions of rows into the HISTORY table. Which two options are true if the total undo space allocated to the DSS_USERS group exceeds the value specified in the undo pool resource plan directive?()
    A

    The batch operation started by the user, SCOTT, terminates with an error.

    B

    The batch operation started by the user, SCOTT, hangs and you are required to increase the undo pool resource plan directive.

    C

    The batch operation started by the user, SCOTT, runs uninterrupted because the database uses the SYSTEM tablespace for the undo operation.

    D

    The user, BLAKE, cannot start a transaction that uses any DML operations until you increase the value of the undo pool resource plan directive.

    E

    The user BLAKE can start a transaction that uses any DML operations after the batch operation started by the user, SCOTT, terminates with an error.


    正确答案: D,A
    解析: 暂无解析

  • 第12题:

    多选题
    You can use Oracle Flashback to look at past activity in your database. What are two other characteristics of Oracle Flashback?()
    A

    Oracle Flashback uses undo information to construct consistent data.

    B

    You can use a cursor opened while using an Oracle Flashback image to perform DML once you deactivate Oracle Flashback in your session.

    C

    You can only use Oracle Flashback view of the data if the required records are still in the online redo log files.

    D

    Oracle Flashback lists the DML that was executed during the period you identify when initiating your session.


    正确答案: D,B
    解析: 暂无解析

  • 第13题:

    What does the DB_FLASHBACK_RETENTION_TARGET parameter configure?()  

    • A、 An upper limit on how far you can flash back the database,depending on the information in the redo logs
    • B、 An upper limit on how far you can flash back the database,depending on the information in the undo tablespace
    • C、 The amount of time for which the flashback data is to be kept in the flash recovery area, provided that there is enough space
    • D、 The amount of time for which the flashback data is guaranteed to be kept in the undo tablespace,provided that there is enough space

    正确答案:C

  • 第14题:

    Which three statements are true about Flashback Database?()

    • A、Flashback logs are written sequentially, and are archived.
    • B、Flashback Database uses a restored control file to recover a database.
    • C、The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area.
    • D、Flashback Database can recover a database to the state that it was in before a reset logs operation.
    • E、Flashback Database can recover a data file that was dropped during the span of time of the flashback.
    • F、Flashback logs are used to restore to the blocks' before images, and then the redo data may be used to roll forward to the desired flashback time.

    正确答案:B,C,F

  • 第15题:

    One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()

    • A、uses undo data for roll forward
    • B、uses Flashback Log for recovery
    • C、uses online redo logs to roll back
    • D、uses undo data to roll back the transaction
    • E、uses Recovery Manager (RMAN) to roll back
    • F、uses the System Monitor (SMON) background process to perform instance recovery

    正确答案:D

  • 第16题:

    You set the undo pool resource plan directive for the consumer group named DSS_USERS that is assigned to the DAY_SHIFT plan. The database users, SCOTT and BLAKE, belong to the DSS_USERS resource group. The user, SCOTT, initiates a database session and executes a batch operation that inserts millions of rows into the HISTORY table. Which two options are true if the total undo space allocated to the DSS_USERS group exceeds the value specified in the undo pool resource plan directive?()

    • A、 The batch operation started by the user, SCOTT, terminates with an error.
    • B、 The batch operation started by the user, SCOTT, hangs and you are required to increase the undo pool resource plan directive.
    • C、 The batch operation started by the user, SCOTT, runs uninterrupted because the database uses the SYSTEM tablespace for the undo operation.
    • D、 The user, BLAKE, cannot start a transaction that uses any DML operations until you increase the value of the undo pool resource plan directive.
    • E、 The user BLAKE can start a transaction that uses any DML operations after the batch operation started by the user, SCOTT, terminates with an error.

    正确答案:A,D

  • 第17题:

    You work as a database administrator for Supportcenter.cn. Your database is in NOARCHIVELOG mode. The database has been configured with three redo logs groups, and there have been five log switches. You lost one non-system-critical data file from your database. Which method would you use to recover the data file?()

    • A、Restore all the data files and open the database
    • B、Create the data file and perform tablespace recovery
    • C、No need to restore any file, just recover the database
    • D、Restore only the system data file and recover the database
    • E、Restore only lost date file and performtablespacerecovery

    正确答案:A

  • 第18题:

    多选题
    Which three statements are true about Flashback Database?()
    A

    Flashback logs are written sequentially, and are archived.

    B

    Flashback Database uses a restored control file to recover a database.

    C

    The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area.

    D

    Flashback Database can recover a database to the state that it was in before a reset logs operation.

    E

    Flashback Database can recover a data file that was dropped during the span of time of the flashback.

    F

    Flashback logs are used to restore to the blocks' before images, and then the redo data may be used to roll forward to the desired flashback time.


    正确答案: B,C,F
    解析: 暂无解析

  • 第19题:

    多选题
    Which two statements regarding the Flashback Table feature are correct?()
    A

    Flashback Table can be performed on system tables.

    B

    Flashback Table operation does not shrink the segments.

    C

    Flashback Table uses log mining to extract SQL_REDO and SQL_UNDO statements.

    D

    Flashback Table operation acquires exclusive data manipulation language (DML) locks.


    正确答案: C,B
    解析: 暂无解析

  • 第20题:

    单选题
    You need to maintain a record of all transactions on some tables for at least three years. Automatic undo management is enabled for the database.What must you do accomplish this task?()
    A

    Enable supplemental logging for the database.

    B

    Specify undo retention guarantee for the database

    C

    Create Flashback Data Archive in the tablespace where the tables are stored.

    D

    Create Flashback Data Archive and enable Flashback Data Archive for specific tables


    正确答案: B
    解析: 暂无解析

  • 第21题:

    多选题
    Which two statements about Flashback Query are true?()
    A

    It is generated by using the redo log files.

    B

    It helps in row-level recovery from user errors.

    C

    It can be performed to recover ALTER TABLE statements

    D

    It fails when undo data pertaining to the transaction is overwritten.

    E

    The database has to be opened with the resetlogs option after performing Flashback Query.


    正确答案: E,C
    解析: 暂无解析

  • 第22题:

    单选题
    You need to maintain a record of all transactions on some tables for at least three years. Automatic undo management is enabled for the database. What must you do accomplish this task?()
    A

     Enable supplemental logging for the database.

    B

     Specify undo retention guarantee for the database

    C

     Create Flashback Data Archive in the tablespace where the tables are stored.

    D

     Create Flashback Data Archive and enable Flashback Data Archive for specific tables


    正确答案: B
    解析: 暂无解析

  • 第23题:

    单选题
    The user SCOTT executes the following command successfully to increase the salary values in one of his sessions:  SQL> UPDATE emp SET sal=sal*1.15 WHERE deptno=20;  Before SCOTT ends the transaction, user HR who has the privileges on EMP table executes a query to fetch the salary details but finds the old salary values instead of the increased values. Why does HR still see the old data?()
    A

    because of redo data from redo log file

    B

    because of data from database buffer cache

    C

    because of data from a temporary tablespace

    D

    because of undo data from the undo tablespace


    正确答案: D
    解析: 暂无解析

  • 第24题:

    单选题
    You work as a database administrator for Certkiller .com. One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it?()
    A

    Uses undo data for roll forward

    B

    Uses Flashback Log for recovery

    C

    Uses online redo logs to roll back

    D

    Uses undo data to roll back the transaction

    E

    Uses Recovery Manager (RMAN) to roll back

    F

    Uses the System Monitor (SMON) background process to perform instance recovery


    正确答案: D
    解析: 暂无解析