Oracle重建控制檔案的例項教程
前言
控制檔案（control file）是一個相當小的檔案（最多能增長到64M左右），其中包含Oracle需要的其他檔案的一個目錄。引數檔案告知例項控制檔案的位置，控制檔案則告知示例資料庫和線上重做日誌檔案的位置。控制檔案還告知了Oracle其他一些事情，如已發生檢查點的有關資訊、資料庫名（必須和db_name引數匹配）、建立資料庫的時間戳、歸檔重做日誌的歷史（有時這會讓控制檔案變大）、RMAN資訊等。
環境：OEL 5.7 + Oracle 10.2.0.5
背景：在Oracle的運維過程中，時常會遇到一些場景是需要重建控制檔案才可以解決的。本文的場景可以通過複製控制檔案到新路徑，執行一段時間後，再用老的控制檔案啟動資料庫重現。
1.當前故障現象
在使用舊的控制檔案啟動資料庫時，報錯ORA-01122、ORA-01110、ORA-01207:
SQL> shutdown abort ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area 599785472 bytes Fixed Size 2098112 bytes Variable Size 218106944 bytes Database Buffers 373293056 bytes Redo Buffers 6287360 bytes Database mounted. ORA-01122: database file 1 failed verification check ORA-01110: data file 1: '/oradata/cxywdb/system01.dbf' ORA-01207: file is more recent than control file - old control file
2.分析故障原因
根據報錯資訊查詢MOS文件:
ORA-1122,ORA-1110,ORA-1207 while open the database after crash (文件 ID 283927.1)
延伸思考一下，為什麼會這樣？
主要錯誤是ORA-01207，利用oerr工具看到Oralce對這個錯誤的詳細描述是：
01207,00000,"file is more recent than control file - old control file"
// *Cause: The control file change sequence number in the data file is
// greater than the number in the control file. This implies that// the wrong control file is being used. Note that repeatedly causing
// this error can make it stop happening without correcting the real
// problem. Every attempt to open the database will advance the
// control file change sequence number until it is great enough.
// *Action: Use the current control file or do backup control file recovery to
// make the control file current. Be sure to follow all restrictions
// on doing a backup control file recovery.
一般遇到這種情況，當前的控制檔案肯定是找不到了。那麼就得考慮重建控制檔案來解決，MOS給出的建議也是重建控制檔案。
3.重建控制檔案
重建控制檔案的核心步驟：
3.1 備份控制檔案到trace
startup mount alter database backup controlfile to trace; oradebug setmypid oradebug tracefile_name
3.2 啟動資料庫到nomount狀態
shutdown abort startup nomount;
3.3 確認重建控制檔案的語句
vi control.sql CREATE CONTROLFILE REUSE DATABASE "CXYWDB" NORESETLOGS FORCE LOGGING ARCHIVELOG MAXLOGFILES 16 MAXLOGMEMBERS 3 MAXDATAFILES 100 MAXINSTANCES 8 MAXLOGHISTORY 292 LOGFILE GROUP 5 '/oradata2/cxywdb/redo11.log' SIZE 50M,GROUP 6 '/oradata2/cxywdb/redo12.log' SIZE 50M,GROUP 7 '/oradata2/cxywdb/redo13.log' SIZE 50M -- STANDBY LOGFILE DATAFILE '/oradata/cxywdb/system01.dbf','/oradata/cxywdb/undotbs01.dbf','/oradata/cxywdb/sysaux01.dbf','/oradata/cxywdb/users01.dbf','/oradata/cxywdb/alfred01.dbf','/oradata/cxywdb/alfred02.dbf','/oradata/cxywdb/alfred03.dbf','/oradata/cxywdb/alfred04.dbf','/oradata/cxywdb/alfred05.dbf','/oradata/cxywdb/dbs_i_alfred01.dbf' CHARACTER SET ZHS16GBK ;
3.4 恢復並開啟資料庫
SQL> recover database; Media recovery complete. SQL> alter database open; Database altered.
附：實際解決過程如下：
SQL> shutdown abort ORACLE instance shut down. SQL> startup mount ORACLE instance started. Total System Global Area 599785472 bytes Fixed Size 2098112 bytes Variable Size 218106944 bytes Database Buffers 373293056 bytes Redo Buffers 6287360 bytes Database mounted. SQL> alter database backup controlfile to trace; Database altered. SQL> oradebug setmypid Statement processed. SQL> oradebug tracefile_name /s01/oracle/admin/cxywdb/udump/cxywdb_ora_3983.trc SQL> shutdown abort ORACLE instance shut down. SQL> startup nomount; ORACLE instance started. Total System Global Area 599785472 bytes Fixed Size 2098112 bytes Variable Size 218106944 bytes Database Buffers 373293056 bytes Redo Buffers 6287360 bytes SQL> @control Control file created. SQL> select status from v$instance; STATUS ------------ MOUNTED SQL> recover database; Media recovery complete. SQL> alter database open; Database altered.
總結
以上就是這篇文章的全部內容了，希望本文的內容對大家的學習或者工作具有一定的參考學習價值，如果有疑問大家可以留言交流，謝謝大家對我們的支援。