Which statement about recovering from the loss of a redo log

第1题：

Which statement is true regarding the Archiver （ARCn） process，archived log files，and recovery？ （）

• A、A database backup, combined with archived redo log files, guarantees that all committed data can be recovered to the point of failure. 
• B、During recovery the ARCn background process copies its redo entries identified for recovery by the control file to the data files. 
• C、After each write to an archived log, the mandatory background process ARCn writes its log sequence number and the first and last SCN number within the log sequence to the control file. 
• D、At database recover time, and archived redo log is uniquely identified for recovery use by its redo thread number and destination ID number retrieved from the control file.

第2题：

You have recovered your Oracle Database 10g by using the control file backup because all copies of the current control file have been lost due to a media failure. You open your database by using the following statement：       SQL>ALTER DATABASE OPEN RESETLOGS；   Which of the following options is true about using the RESETLOGS option？（）

• A、 The log sequence is reset to 0.
• B、 All the online redo logs are deleted.
• C、 All the archived redo logs from a previous incarnation become useless.
• D、 The full database backup taken from a previous incarnation can be used in future.
• E、 Only the control file and online redo log files are updated with a new RESETLOGS SCN and time stamp.

第3题：

第4题：

The loss of which two types of files may require a recovery with the RESETLOGS option？（）

• A、 control files
• B、 password file
• C、 archived log files
• D、 system-critical data files for which all the redo entries are present
• E、 non-system-critical data files for which all the redo entries are present

第5题：

You performed an incomplete recovery and opened the database with the RESETLOGS option. The LOG_ARCHIVE_FORMAT parameter is set to ’ora_%t_%s_%r.log’.  Which statement regarding the archived redo log files， created in an earlier incarnation of the database，is true？（）

• A、 The archived redo log files will be overwritten.
• B、 The archived redo log files are deleted automatically.
• C、 The archived redo log files should be moved to some other location.
• D、 The archived redo log files are still maintained because the file names are unique.

第6题：

You are working on Oracle Database 10g， which is in ARCHIVELOG mode. All the archived log files are intact.  In which scenario would performing a recovery require the opening of the database with the RESETLOGS option？（）

• A、loss of a tempfile
• B、loss of a system data file
• C、loss of one of the control files
• D、loss of one of the tablespaces
• E、loss of a member from each redo log group
• F、loss of the only member of an unarchived redo log group

第7题：

Which two operations require undo data？（）

• A、committing a transaction
• B、rolling back a transaction
• C、recovering from failed transactions
• D、recording a transaction to redo log files
• E、rolling forward during instance recovery

第8题：

Redo log files are multiplexed in your database. The disk in which you have one of the redo log members is highly fragmented. In the process of defragmentation you lose the redo log member， which is not a member of the current group. How would you recover from the loss of the redo log member？（）

• A、SMON would automatically restore the lost file.
• B、You would need to restore the whole database from the last backup.
• C、You would need to restore the file from the last full database backup.
• D、You would need to use flashback technology to restore the lost redo log member.
• E、You would need to use Recovery Manager （RMAN） to restore the lost redo log member.
• F、You would need to restore the missing log file by copying one of the remaining files from the same group.

第9题：

Because of hardware failure， you decided to drop a redo log member from the database. Which condition should be met to drop a redo log file？（）

• A、 The redo log file should belong to an active group.
• B、 The redo log file should belong to an inactive group.
• C、 The redo log file should belong to the current group.
• D、 The redo log file can be dropped only if all the transactions are stopped.
• E、 Before a redo log file is dropped， it should be deleted from the operating system （OS）.

第10题：

In which of the following scenarios is a tablespace recovery required？（）

• A、 when recovering a lost read-only tablespace from a read-only tablespace backup
• B、 when recovering a lost read-only tablespace from a read-write tablespace backup when the database is running in  ARCHIVELOG mode
• C、 when recovering a lost read-only tablespace from a read-write tablespace backup when the database is running in  NOARCHIVELOG mode and the changes in the online redo log files have been overwritten
• D、 when recovering a lost read-only tablespace from a read-only tablespace backup using the backup of the control file， the control file was created using the ALTER DATABASE BACKUP CONTROLFILE TO TRACE statement， and this statement was issued when the tablespace was read-only