多项选择题
A.The online redo log files and online data files are opened.
B.All the online data file headers are checked for consistency.
C.Instance recovery is performed before opening the database.
D.The path and existence of all the log file members are checked
单项选择题 InwhichsituationistheUNDO_RETENTIONparameterbeignored，evenifitissettoavalue（）
多项选择题 The user HR receives the following error while inserting data into the TTK table：ERROR at line 1： ORA-01653： unable to extend table HR.TTK by 128 in tablespace SMD Upon investigation， you find that SMDis a small file tablespace. Which three action would allow the user to insert data（）
单项选择题 View the Exhibit and examine the attributes of an undo tablespace. In an OLTP system, the user SCOTT hasstarted a query on a large table in the peak transactional hour that performs bulk inserts. The query runs formore than 15 minutes and then SCOTT receives the following error:ORA-01555: snapshot too old What could be the reason for this error（）