56、
56.Your database instance is configured with automatic undo management and the UNDO_RETENTION parameter is set to 900 seconds. You executed the following command to enable retention guarantee: SQL> ALTER TABLESPACE undotbs1 RETENTION GUARANTEE; What affect would this command have on the database? A. The extents in the undo tablespace retain data until the next full database backup B. The extents containing committed undo in the undo tablespace are not overwritten for at least 15 minutes C. The extents containing committed data in the undo tablespace are not overwritten until the instance is shut down D. The extents containing committed undo in the undo tablepace are transferred to Flash Recovery Area before being overwritten
Answer: B
保证还原保留时间
57、
57.You configured the Flash Recovery Area for your database. The database instance has been started in ARCHIVELOG mode and the LOG_ARCHIVE_DEST_1 parameter is not set. What will be the implications on the archiving and the location of archive redo log files? A. Archiving will be disabled because the destination for the redo log files is missing B. The database instance will shut down and the error details will be logged in the alert log file C. Archiving will be enabled and the destination for the archived redo log file will be set to the Flash Recovery Area implicitly D. Archiving will be enabled and the location for the archive redo log file will be created in the default location $ORACLE_HOME/log
Answer: C
启用了快速恢复区，则指定USE_DB_RECOVERY_FILE_DEST作为归档日志文件目标位置
58、
58.Which is the correct description of a pinned buffer in the database buffer cache? A. The buffer is currently being accessed B. The buffer is empty and has not been used C. The contents of the buffer have changed and must be flushed to the disk by the DBWn process D. The buffer is a candidate for immediate aging out and its contents are synchronized with the block contents on the disk
Answer: A
59、
59.In which situation would you use static database registration for a listener? A. When multiple databases are to be registered with the listener B. When DBAs need to connect remotely to start up the database instance C. When users need to connect the database instance using the host naming method D. When the database instance that is to be registered with the listener is configured in shared server mode
Answer: B
60、
60.While observing the index statistics, you find that an index is highly fragmented, thereby resulting in poor database performance. Which option would you use to reduce fragmentation without affecting the users who are currently using the index? A. Validate the index structure using the ANALYZE .... INDEX command B. Rebuild the index using the ALTER INDEX ..... REBUILD ONLINE command C. Change the block space utilization parameters using the ALTER INDEX command D. Deallocate the unused space in the index using the ALTER INDEX ... DEALLOCATE UNUSED command
Answer: B