同一台IBM 小机上安装11g 单实例和12c RAC
使用不同的profile，让不同profile生效的方法如下
操作系统为AIX 7
<oracle:oggs2:/home/oracle**>$. ~/.profile_11g**
<oracle:orcl:/home/oracle>$sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Mon Oct 29 22:54:23 2018
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> 原文：http://blog.51cto.com/roidba/2310585