參考文獻：
http://10000001.blog.51cto.com/4600383/1248367
背景：
使用sqlplus連接oracle，提示ORA-01034和ORA-27101，具體內容如下：
ERROR: ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist Process ID: 0 Session ID: 0 Serial number: 0
解決方法是執行以下命令：
C:\Documents and Settings\Administrator>sqlplus /nolog SQL*Plus: Release 11.2.0.1.0 Production on Thu Nov 7 17:16:47 2013 Copyright (c) 1982, 2010, Oracle. All rights reserved. SQL> conn / as sysdba Connected to an idle instance. SQL> startup ORACLE instance started. Total System Global Area 778387456 bytes Fixed Size 1374808 bytes Variable Size 503317928 bytes Database Buffers 268435456 bytes Redo Buffers 5259264 bytes Database mounted. Database opened.
此時可能會報出ORA-03113這樣的錯誤，如下所示
SQL> startup ORACLE instance started. Total System Global Area 3423965184 bytes Fixed Size 2180544 bytes Variable Size 2550139456 bytes Database Buffers 855638016 bytes Redo Buffers 16007168 bytes Database mounted. ORA-03113: end-of-file on communication channel Process ID: 9116 Session ID: 191 Serial number: 3
對於 ORA-03113: end-of-file on communication channel，可以參考另外一篇文章。