单项选择题 The user SCOTT executes the following command successfully to increase the salary values in one of his sessions：  SQL> UPDATE emp SET sal=sal*1.15 WHERE deptno=20；  Before SCOTT ends the transaction， user HR who has the privileges on EMP table executes a query to fetch the salary details but finds the old salary values instead of the increased values. Why does HR still see the old data？（）

单项选择题 Your database is started by using the server parameter file （SPFILE）. You issued this command to change the value of the LOG_BUFFER initialization parameter：  ALTER SYSTEM SET LOG_BUFFER=24M SCOPE=BOTH；  What would be the outcome of this command？ （）

单项选择题 YouworkasadatabaseadministratorforSupportcenter.cn.Youdeterminethatarchivingwasnotsuccessfulinoneofthedestinators.Youwanttocheckthealertlogfileformoreinformationonthis.Whichinitializationparametergivesyouthelocationofthealertlogfile？（）