dataguard的gap是生産端存在容災段沒有應用的日志,一般情況下,dataguard會自動消除gap。
下面提供手工消除gap的方法:
1.在備庫查詢有哪些日志丢失,沒應用到備庫
SQL> select * from V$ARCHIVE_GAP;
THREAD# LOW_SEQUENCE# HIGH_SEQUENCE#
---------- ------------- --------------
1 9873 9876
我們可以看到9873到9876這四個歸檔日志丢失,
2.我們在主庫找到這四個歸檔日志傳送到備庫歸檔目錄下;
3.備庫注冊
alter database register logfile '/oracle/app/oracle/archive/1_9873_629923600.arc';
system alerted
alter database register logfile '/oracle/app/oracle/archive/1_9874_629923600.arc';
system alerted
alter database register logfile '/oracle/app/oracle/archive/1_9875_629923600.arc';
system alerted
alter database register logfile '/oracle/app/oracle/archive/1_9876_629923600.arc';
system alerted
4.檢查資料庫日志看是否應用
Thu Apr 8 15:55:17 2010
Media Recovery Log /oracle/app/oracle/archive/1_9873_629923600.arc
Media Recovery Log /oracle/app/oracle/archive/1_9874_629923600.arc
Media Recovery Log /oracle/app/oracle/archive/1_9875_629923600.arc
Media Recovery Log /oracle/app/oracle/archive/1_9876_629923600.arc
或者查詢視圖
v$archived_log的applied字段
5、檢查備庫是否還有日志GAP
SQL> select * from V$ARCHIVE_GAP;
出現沒有行選擇,則表示不存在歸檔日志丢失問題