简述游标的作用和游标操作的基本步骤。
简述游标的作用和游标操作的基本步骤。
相关考题：
You find today’s performance of your production database to be the best ever. Therefore， you want to be notified in the future whenever the performance degrades by 10% of today’s performance. What is the first step that you would take to ensure this？（）A、create baseline metrics for today’s performanceB、write the current database metrics to a database table and create a trigger to compare with future database statisticsC、write the current database metrics to a flat file and create an operating script to compare with future database statisticsD、write the current database metrics to a database table and create a procedure to compare with future database statisticsE、write the current database metrics to a database table and submit a job using DBMS_JOB to compare with future database statistics
Which three SELECT statements displays 2000 in the format “$2,000.00”?（）A、SELECT TO CNAR(2000, ‘$#,###.##’) FROM dual;B、SELECT TO CNAR(2000, ‘$0,000.00’) FROM dual;C、SELECT TO CNAR(2000, ‘$9,999.00’) FROM dual;D、SELECT TO CNAR(2000, ‘$9,999.99’) FROM dual;E、SELECT TO CNAR(2000, ‘$2,000.00’) FROM dual;F、SELECT TO CNAR(2000, ‘$N,NNN.NN’) FROM dual;
Which command would you use to determine what database backups are currently available for restore?（）A、list database backupB、report database backup C、list backup of databaseD、list summary backupE、report backup of database
Which two tasks can your perform by using the TO_CHAR function? （）A、Convert 10 to 'TEN'B、Convert '10' to 10C、Convert '10' to '10'D、Convert 'TEN' to 10E、Convert a date to a character expressionF、Convert a character expression to a date
You are managing an Oracle Database 11g database with this backup strategy： - Every Sunday night， level 0 backup is performed. - On Monday night and subsequent days， level 1 incremental backup is performed. The backups are not cumulative incremental. Which statement about Monday’s backup is true（）A、The backup contains all the used blocks.B、The backup contains all the used and unused blocks.C、The backup contains blocks that have changed since the last level 0 backup.D、The backup contains blocks that have changed since the last level 1 backup taken last week.
Which two Oracle products come pre-packaged with Oracle’s JRockit JDK ？（）A、 Oracle WebLogic ServerB、 Oracle CoherenceC、 Oracle DatabaseD、 Oracle Real Time Operations Control
What are the two advantages of RMAN Block Media Recovery （BMR） over file/x7flevel recovery？（）A、BMR lowers the mean time to recover （MTTR）.B、BMR supports pointintime recovery of individual data blocks.C、BMR enables you to use incremental backups for block recovery.D、BMR enables recovery even when the database is not mounted or open.E、BMR enables you to use proxy backups to perform block media recovery.F、BMR enables increased availability of data during recovery because the data file that requires a recovery can remain online.
Your database is using shared server configuration. Which optional memory structure would you configure to store the User Global Area （UGA） information and improve the shared pool performance？（）A、large poolB、streams poolC、keep buffer cacheD、recycle buffer cache
You work as a database administrator for Certkiller .com. You have been asked to use a centralized administrative tool to administer your database servers and application servers. In order to achieve the objective， which component would you configure on each database server？（）A、Database ControlB、Management ServerC、Management RepositoryD、Application Server ControlE、Oracle Management Agent
Your database is functioning in ARCHIVELOG mode. In which two situations would you perform a cancel-based recovery？ （）A、 You find that one of the redo log members in each redo log group is lost.B、 You find that a data file that belongs to the USERS tablespace is damaged.C、 You find that a data file that belongs to the SYSTEM tablespace is damaged.D、 You find that the current redo log group is damaged and is not available for recovery.E、 You realized while performing a recovery that an archived redo log file needed for recovery is lost.