THREAD# NAME size
---------- ---------------------------------------------------------------------- ----------
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_10.268.861729569 1.4453125
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_11.270.861730475 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_12.271.861730509 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_13.272.861730545 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_14.274.861730573 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_23/thread_1_seq_15.275.861730601 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_16.276.861788401 35.8242188
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_17.278.861791005 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_18.279.861791039 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_19.281.861791071 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_20.282.861791091 49.9980469
1 +DATADG01/gyl/archivelog/2014_10_24/thread_1_seq_21.283.861791119 49.9980469
2 +DATADG01/gyl/archivelog/2014_10_23/thread_2_seq_2.269.861729571 2.37207031
2 +DATADG01/gyl/archivelog/2014_10_23/thread_2_seq_3.273.861730551 .008300781
2 +DATADG01/gyl/archivelog/2014_10_24/thread_2_seq_4.277.861788403 .567871094
2 +DATADG01/gyl/archivelog/2014_10_24/thread_2_seq_5.280.861791047 .791503906
2 +DATADG01/gyl/archivelog/2014_10_24/thread_2_seq_6.284.861791125 .000976563
（thread_1_seq_17至thread_1_seq_21为insert过程中节点1产生的归档，大小都接近redo file大小，thread_2_seq_5和thread_2_seq_6为节点2产生的归档，远小于redo file大小）
SQL> select GROUP#,THREAD#,SEQUENCE#,STATUS,FIRST_CHANGE# from v$log order by 2;
GROUP# THREAD# SEQUENCE# STATUS FIRST_CHANGE#
---------- ---------- ---------- ---------------- -------------
1 1 21 ACTIVE 1206256
2 1 22 CURRENT 1308608
3 2 7 CURRENT 1338258
4 2 6 INACTIVE 1014874
（可以看到，节点2的FIRST_CHANGE#也跟进了，这里还超过了节点1的）
再考虑一种极端情况，如果节点2已经down了，那么，节点2的归档将会由节点1进行代为执行，同样会推进节点2的redo log的FIRST_CHANGE#，继续上面的实验：
--关闭节点2
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
--继续在节点1插入数据
begin
for i in 1..500000 loop
insert into darren values(1,'aa');
commit;
end loop;
end;
--查看归档情况和redo log 的FRIST_CHANGE#
SQL> select thread#,ARCHIVAL_THREAD#,name,blocks*block_size/1024/1024 "size" from v$archived_log order by 1,2;