单项选择题

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

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热门试题

单项选择题You are working in an online transaction processing (OLTP) environment. You use the FLASHBACKTABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command, the system change number (SCN) was 663571. After flashing back the CUSTOMERS table, you realize that the table is not in the correct state. Now, you need to reverse the effects of the FLASHBACK TABLE command. Which is the fastest and the most efficient option to reverse the effects of the FLASHBACK TABLE command?（）

A. Restore the backup control file and open the database with RESETLOGS option.
B. Perform point-in-time recovery because flashback cannot be performed again on this table
C. Execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571
D. Execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571

多项选择题Which two statements are true about the Automatic Diagnostic Repository (ADR)?（）

A. The ADR base keeps all diagnostic information in binary format
B. SQL*Plus provides the ADRI script, which can be used to work with ADR
C. The ADR can be used for problem diagnosis only when the database is open
D. The ADR can be disabled by settting the DIAGNOSTIC_DEST parameter to null
E. The ADR can be used for problem diagnosis even when the database instance is down
F. The ADR base is shared across multiple instances

多项选择题You want to take a complete database backup using RMAN. The backup should consist only the used blocks from your database.Which two statements are true about this backup operation?（）

A. Backup compression should be enabled
B. Parallelism for the channel should be set to 2
C. All the files must be backed up as backup sets
D. The backup may be stored either on disk or on media with media manager

多项选择题Which options would you consider while configuring a flash recovery area (fast recovery area in 11g Release 2) for your production database that is running in ARCHIVELOG mode?（）

A. Setting the FAST_START_MTTR_TARGET to set the mean time to recover
B. Setting the RECOVERY_PARALLELISM parameter to twice the number of CPUs
C. Using the DB_RECOVERY_FILE_DEST parameter to set the location for flash recovery area
D. Using the DB_RECOVERY_FILE_DEST_SIZE parameter to define the disk space limit for the recovery files created in the flash recovery area

多项选择题To enable faster incremental backups, you enabled block change tracking for the database.Which two statements are true about the block change tracking file?（）

A. Multiple change tracking files can be created for a database.
B. The change tracking file must be created after the first level 0 backup.
C. RMAN does not support backup and recovery of the change tracking file.
D. The database clears the change tracking file and starts tracking changes again, after whole database restore and recovery operations.