? ? GROUP#? ? THREAD#? SEQUENCE#? ? ? BYTES? BLOCKSIZE? ? MEMBERS ARC STATUS? ? ? ? ? FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
? ? ? ? 1? ? ? ? ? 1? ? ? ? 133? 52428800? ? ? ? 512? ? ? ? ? 1 YES INACTIVE? ? ? ? ? ? ? 3155684 15-FEB-15? ? ? 3155687 15-FEB-15
? ? ? ? 2? ? ? ? ? 1? ? ? ? 134? 52428800? ? ? ? 512? ? ? ? ? 1 NO? CURRENT? ? ? ? ? ? ? ? 3155687 15-FEB-15? 2.8147E+14
? ? ? ? 3? ? ? ? ? 1? ? ? ? 132? 52428800? ? ? ? 512? ? ? ? ? 1 YES INACTIVE? ? ? ? ? ? ? 3155681 15-FEB-15? ? ? 3155684 15-FEB-15
SQL> select file#,status from v$datafile where file#=9;
? ? FILE# STATUS
---------- -------
? ? ? ? 9 OFFLINE
SQL> select file#,status from v$datafile_header where file#=9;
? ? FILE# STATUS
---------- -------
? ? ? ? 9 OFFLINE
SQL> alter database datafile 9 online;
Database altered.
SQL> select file#,status from v$datafile where file#=9;
? ? FILE# STATUS
---------- -------
? ? ? ? 9 ONLINE
SQL>
知识点：
1.The only case in which the offline dropped datafile can not be online is
when you have added to many datafiles in the database after offline drop
2.在非归档模式下，为了让一个datafile 变成offline，必须带drop关键字。
drop关键字不会把datafile从database 中 remove掉。
?To do that, you must drop the tablespace in which the datafile resides. Until you
?do so, the datafile remains in the data dictionary with the status RECOVER or OFFLINE.
? ?
?若是database处于归档模式，Oracle会忽略掉drop 关键字.