单项选择题 The warning level threshold value for a tablespace， DATA1， is set to 60% and the critical level threshold value is set to 80%. The tablespace， DATA1， is infrequently used and is not a part of the production environment. You issued the following command：        SQL> EXECUTE   DBMS_SERVER_ALERT.SET_THRESHOLD        （dbms_server_alert.tablespace_pct_full，        dbms_server_alert.operator_ge，80，        dbms_server_alert.operator_ge，90，        1，1，NULL，   dbms_server_alert.object_type_tablespace，’DATA’）；   What will be the result of the command？（）

单项选择题 AjuniorlevelDatabaseAdministratorerroneouslydeletedthedatabasealertlogwhileuserswereaccessingthedatabase.Whichactionshouldyoutaketorecoverthealertlog？（）

单项选择题 YouaremaintainingthePRODdatabaseofNetFxCorporation.YousetthevalueoftheSQL_TRACEparametertoTRUE.Whatwillbetheimpactofthissetting？（）