本案例数据库（12.1.0.2）安装在文件系统上，因此只需要deinstall 数据库即可。
前提：
(1)关闭数据库，shutdown immediate;
(2)关闭监听，lsnrctl stop
(3)最后，deinstall数据库

[root@roidb01 database]# su - oracle
$cd $ORACLE_HOME/
$cd deinstall/
$./deinstall
Checking for required files and bootstrapping ...
Please wait ...

Location of logs /tmp/deinstall2018-08-13_09-28-09AM/logs/

############ ORACLE DECONFIG TOOL START ############

######################### DECONFIG CHECK OPERATION START #########################
## [START] Install check configuration ##

Checking for existence of the Oracle home location /u01/app/oracle/product/12.1.0/dbhome_1
Oracle Home type selected for deinstall is: Oracle Single Instance Database
Oracle Base selected for deinstall is: /u01/app/oracle
Checking for existence of central inventory location /u01/app/oraInventory

## [END] Install check configuration ##

Network Configuration check config START

Network de-configuration trace file location: /tmp/deinstall2018-08-13_09-28-09AM/logs/netdc_check2018-08-13_09-28-37-AM.log

Specify all Single Instance listeners that are to be de-configured. Enter .(dot) to deselect all. [LISTENER]:

Network Configuration check config END

Database Check Configuration START

Database de-configuration trace file location: /tmp/deinstall2018-08-13_09-28-09AM/logs/databasedc_check2018-08-13_09-30-18-AM.log

Use comma as separator when specifying list of values as input

Specify the list of database names that are configured in this Oracle home [cdb1,cdb2]: 

###### For Database 'cdb1' ######

Single Instance Database
The diagnostic destination location of the database: /u01/app/oracle/diag/rdbms/cdb1
Storage type used by the Database: FS
Database file location: /u01/app/oracle/oradata/cdb1
Fast recovery area location: Does not exist
database spfile location: /u01/app/oracle/product/12.1.0/dbhome_1/dbs/spfilecdb1.ora

###### For Database 'cdb2' ######

Single Instance Database
The diagnostic destination location of the database: /u01/app/oracle/diag/rdbms/cdb2
Storage type used by the Database: FS
Database file location: /u01/app/oracle/oradata/cdb2
Fast recovery area location: Does not exist
database spfile location: /u01/app/oracle/product/12.1.0/dbhome_1/dbs/spfilecdb2.ora

The details of database(s) cdb1,cdb2 have been discovered automatically. Do you still want to modify the details of cdb1,cdb2 database(s)? [n]: 

Database Check Configuration END
Oracle Configuration Manager check START
OCM check log file location : /tmp/deinstall2018-08-13_09-28-09AM/logs//ocm_check1059.log
Oracle Configuration Manager check END

######################### DECONFIG CHECK OPERATION END #########################

####################### DECONFIG CHECK OPERATION SUMMARY #######################
Oracle Home selected for deinstall is: /u01/app/oracle/product/12.1.0/dbhome_1
Inventory Location where the Oracle home registered is: /u01/app/oraInventory
Following Single Instance listener(s) will be de-configured: LISTENER
The following databases were selected for de-configuration : cdb1,cdb2
Database unique name : cdb1
Storage used : FS
Database unique name : cdb2
Storage used : FS
Checking the config status for CCR
Oracle Home exists with CCR directory, but CCR is not configured
CCR check is finished
Do you want to continue (y - yes, n - no)? [n]: y
A log of this session will be written to: '/tmp/deinstall2018-08-13_09-28-09AM/logs/deinstall_deconfig2018-08-13_09-28-35-AM.out'
Any error messages from this session will be written to: '/tmp/deinstall2018-08-13_09-28-09AM/logs/deinstall_deconfig2018-08-13_09-28-35-AM.err'

######################## DECONFIG CLEAN OPERATION START ########################
Database de-configuration trace file location: /tmp/deinstall2018-08-13_09-28-09AM/logs/databasedc_clean2018-08-13_09-31-53-AM.log
Database Clean Configuration START cdb1
This operation may take few minutes.
Database Clean Configuration END cdb1
Database Clean Configuration START cdb2
This operation may take few minutes.
Database Clean Configuration END cdb2

Network Configuration clean config START

Network de-configuration trace file location: /tmp/deinstall2018-08-13_09-28-09AM/logs/netdc_clean2018-08-13_09-34-41-AM.log

De-configuring Single Instance listener(s): LISTENER

De-configuring listener: LISTENER
    Stopping listener: LISTENER
    Listener stopped successfully.
    Deleting listener: LISTENER
    Listener deleted successfully.
Listener de-configured successfully.

De-configuring Local Net Service Names configuration file...
Local Net Service Names configuration file de-configured successfully.

De-configuring backup files...
Backup files de-configured successfully.

The network configuration has been cleaned up successfully.

Network Configuration clean config END

Oracle Configuration Manager clean START
OCM clean log file location : /tmp/deinstall2018-08-13_09-28-09AM/logs//ocm_clean1059.log
Oracle Configuration Manager clean END

######################### DECONFIG CLEAN OPERATION END #########################

####################### DECONFIG CLEAN OPERATION SUMMARY #######################
Successfully de-configured the following database instances : cdb1,cdb2
Following Single Instance listener(s) were de-configured successfully: LISTENER
Cleaning the config for CCR
As CCR is not configured, so skipping the cleaning of CCR configuration
CCR clean is finished
###################################################################

############# ORACLE DECONFIG TOOL END #############

Using properties file /tmp/deinstall2018-08-13_09-28-09AM/response/deinstall_2018-08-13_09-28-35-AM.rsp
Location of logs /tmp/deinstall2018-08-13_09-28-09AM/logs/

############ ORACLE DEINSTALL TOOL START ############

####################### DEINSTALL CHECK OPERATION SUMMARY #######################
A log of this session will be written to: '/tmp/deinstall2018-08-13_09-28-09AM/logs/deinstall_deconfig2018-08-13_09-28-35-AM.out'
Any error messages from this session will be written to: '/tmp/deinstall2018-08-13_09-28-09AM/logs/deinstall_deconfig2018-08-13_09-28-35-AM.err'

######################## DEINSTALL CLEAN OPERATION START ########################
## [START] Preparing for Deinstall ##
Setting LOCAL_NODE to orcl
Setting CRS_HOME to false
Setting oracle.installer.invPtrLoc to /tmp/deinstall2018-08-13_09-28-09AM/oraInst.loc
Setting oracle.installer.local to false

## [END] Preparing for Deinstall ##

Setting the force flag to false
Setting the force flag to cleanup the Oracle Base
Oracle Universal Installer clean START

Detach Oracle home '/u01/app/oracle/product/12.1.0/dbhome_1' from the central inventory on the local node : Done

Delete directory '/u01/app/oracle/product/12.1.0/dbhome_1' on the local node : Done

Delete directory '/u01/app/oraInventory' on the local node : Done

The Oracle Base directory '/u01/app/oracle' will not be removed on local node. The directory is not empty.

Oracle Universal Installer cleanup was successful.

Oracle Universal Installer clean END

## [START] Oracle install clean ##

Clean install operation removing temporary directory '/tmp/deinstall2018-08-13_09-28-09AM' on node 'orcl'

## [END] Oracle install clean ##

######################### DEINSTALL CLEAN OPERATION END #########################

####################### DEINSTALL CLEAN OPERATION SUMMARY #######################
Successfully detached Oracle home '/u01/app/oracle/product/12.1.0/dbhome_1' from the central inventory on the local node.
Successfully deleted directory '/u01/app/oracle/product/12.1.0/dbhome_1' on the local node.
Successfully deleted directory '/u01/app/oraInventory' on the local node.
Oracle Universal Installer cleanup was successful.

Run 'rm -r /etc/oraInst.loc' as root on node(s) 'orcl' at the end of the session.

Run 'rm -r /etc/oratab' as root on node(s) 'orcl' at the end of the session.
Oracle deinstall tool successfully cleaned up temporary directories.
#######################################################################

############# ORACLE DEINSTALL TOOL END #############
$exit
logout
[root@roidb01 database]# rm -r /etc/oraInst.loc
rm: remove regular file ‘/etc/oraInst.loc’? y
[root@roidb01 database]# rm -r /etc/oratab
rm: remove regular file ‘/etc/oratab’? y

$env |grep ORA
ORACLE_UNQNAME=orcl
ORA_NLS11=/u01/app/oracle/product/12.1.0/dbhome_1/nls/data
ORACLE_SID=cdb1
ORACLE_BASE=/u01/app/oracle
ORACLE_TERM=xterm
PS1=$
ORACLE_HOME=/u01/app/oracle/product/12.1.0/dbhome_1
$cd $ORACLE_BASE
$ls
admin  audit
$rm -rf *
$