步骤一：关闭数据库
export ORACLE_SID=bgsp
1. sqlplus / as sysdba
2. shutdown immediate
步骤二：删除实例相关文件
1. find $ORACLE_BASE/ -name $ORACLE_SID
2. 用命令删除查询后的文件
find $ORACLE_BASE/ -name $ORACLE_SID -exec rm -rf {} ;
步骤三：删除配置文件，假设我们删除的实例是YC
1. find $ORACLE_BASE/* -name '*[Yy][Cc]*' | grep -v admin | grep -v oradata
2. 用命令删除查询的文件
find $ORACLE_BASE/* -name '*[Yy][Cc]*' | grep -v admin | grep -v oradata | xargs rm -rf
步骤四：删除实例配置文件中的信息
1. vim /etc/oratab
2. 找到yc:/opt/oracle/db/product/11g:N
3. 将该行信息删除，并保存文件
经过以上步骤可以实现命令行干净的删除实例
原来这个机器上装过oracle，卸载了，选择之前安装的目录（已经删除干净了），就出现了 “[INS-32025] 所选安装与指定 Oracle 主目录中已安装的软件冲突” 的问题，解决办法为：删除C:Program Files (x86)OracleInventoryContentsXML目录下的inventory.xml 文件即可。（附带改文件内容，该目录地址在这里被占用了，所以会报错）
我是直接把oracle下面的文件都删了
[12:41:16 oracle(db_1)@rhel65 database]$ ./runInstaller -silent -showProgress -ignoreSysPrereqs -responseFile /home/oracle/soft/database/response/db_install.rsp
Starting Oracle Universal Installer...
Checking Temp space: must be greater than 120 MB. Actual 7246 MB Passed
Checking swap space: must be greater than 150 MB. Actual 3999 MB Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2019-05-26_12-41-19PM. Please wait ...[12:41:21 oracle(db_1)@rhel65 database]$ [FATAL] [INS-32025] The chosen installation conflicts with software already installed in the given Oracle home.
CAUSE: The chosen installation conflicted with software already installed in the given Oracle home.
ACTION: Install into a different Oracle home.
[12:48:54 root()@rhel65 ~]# find / -name inventory.xml
/usr/oracle/oraInventory/backup/2019-05-18_11-49-20PM/ContentsXML/inventory.xml
/usr/oracle/oraInventory/ContentsXML/inventory.xml
[12:49:06 root()@rhel65 ~]# rm /usr/oracle/oraInventory/backup/2019-05-18_11-49-20PM/ContentsXML/inventory.xml
rm: remove regular file `/usr/oracle/oraInventory/backup/2019-05-18_11-49-20PM/ContentsXML/inventory.xml'?
[12:49:18 root()@rhel65 ~]# rm -Rf /usr/oracle/oraInventory/backup/2019-05-18_11-49-20PM/ContentsXML/inventory.xml
[12:49:23 root()@rhel65 ~]# rm -Rf /usr/oracle/oraInventory/ContentsXML/inventory.xml