about installing 2 different versions of Oracle server ____oracle on a single host

I. Installation of ORACLE12C

Install as normal installation method.

Oracle_base=/u01/app

Oracle_home=/u01/app/oracle

Oracle_sid=a4orcl

Second, install oracle11g

When installing oracle11g, the installation directory and related parameters are selected as follows:

Su-oracle

Oracle_base=/u01/app

Oracle_home=/u02/app/oracle

Oracle_sid=a4orcl02

After the installation is complete, you may need to configure/u02/app/oracle/network/admin/listener.ora

Add the following:

Sid_list_listener =
(Sid_list =
(Sid_desc =
(Global_dbname = a4orcl02)
(Oracle_home =/u02/app/oracle)
(Sid_name = a4orcl02)
)
)

Note that the port at oracle11g login is already 1522.

#根据不同的需求登录不同的数据库, where $oracle_home can be introduced temporarily by using export

Export Oracle_home=/u01/app/home

$ORACLE _home/bin/sqlplus

$ORACLE _HOME/BIN/DBCA

Iii. documents to be used

More/etc/orainst.loc
Inventory_loc=/u01/orainventory
Inst_group=oinstall


More/etc/oratab
A4orcl:/u01/app/oracle:n