ORACLE資料庫的啟動

 

啟動ORACLE：

• 第一步是啟動實例本身(nomount)。實例(instance)指的就是已分配的記憶體(SGA)和各種後臺進程(process)的集合。此時可進行一些修復作業，如重建控制檔、重建資料庫。
  

  SQL> STARTUP NOMOUNT
  

• 第二步是掛載(mount)資料庫，此時可訪問資料庫檔。該階段可執行的一些操作：資料庫日誌歸檔、資料庫恢復、重新命名一些資料庫檔(如：系統表空間和日誌檔)，此時使用者仍然不可訪問資料庫。。
  

  SQL> STARTUP MOUNT
  

  or
  

  SQL> ALTER DATABASE MOUNT;
  

• 最後一步是打開(open)資料，此時使用者可訪問資料庫中的資料。 
  

  SQL> STARTUP
  

  Or
  

  SQL> ALTER DATABASE OPEN;
  

• 正常啟動資料庫需要完成這三個步驟。你可以把資料庫停留在以上任一步驟，如果你需要進行一些DBA工作，還可以把資料庫開在限制模式(restricted mode)：
  

SQL> STARTUP RESTRICT

--

SQL> alter system enable restricted session;

--

SQL> alter system disable restricted session;

 

startup

[oracle@dyora01 ~]$ sqlplus /nolog   SQL*Plus: Release 10.2.0.1.0 - Production on Mon Jan 21 07:04:30 2002   Copyright (c) 1982, 2005, Oracle. All rights reserved.   SQL> connect / as sysdba Connected. SQL> shutdown immediate Database closed. Database dismounted. ORACLE instance shut down. SQL> startup nomount ORACLE instance started.   Total System Global Area 356515840 bytes Fixed Size 1219376 bytes Variable Size 100664528 bytes Database Buffers 247463936 bytes Redo Buffers 7168000 bytes SQL> alter database mount;   Database altered.   SQL> alter database open;   Database altered.   SQL> shutdown immediate Database closed. Database dismounted. ORACLE instance shut down. SQL> startup mount ORACLE instance started.   Total System Global Area 356515840 bytes Fixed Size 1219376 bytes Variable Size 100664528 bytes Database Buffers 247463936 bytes Redo Buffers 7168000 bytes Database mounted. SQL> startup ORA-01081: cannot start already-running ORACLE - shut it down first SQL> shutdown immediate ORA-01109: database not open     Database dismounted. ORACLE instance shut down. SQL> startup ORACLE instance started.   Total System Global Area 356515840 bytes Fixed Size 1219376 bytes Variable Size 100664528 bytes Database Buffers 247463936 bytes Redo Buffers 7168000 bytes Database mounted. Database opened. SQL>

 

延伸內容

Problems during Oracle Startup

ORACLE資料庫的關閉：