环境变量多个斜杠引起ORA-12547: TNS:lost contact

前言：

相信ORA-12547: TNS:lost contact这种问题已经是烂大街的了，但是本次的问题真是那些oracle执行文件权限，白名单，资源限制，共享内存等等之类的问题吗？

一、环境信息

数据库版本：19c

二、问题复现

因为某个情况，在创建或者启动数据库的时候设置了ORACLE_HOME环境变量，并且结尾过了一个斜杠，例如：
export ORACLE_HOME=$ORACLE_BASE/product/19.5.0/dbhome_1/；这时候你数据库本地环境变量是设置没有斜杠，那进行sqlplus连接则会出现ORA-12547的错误。

[oracle@William ]$export ORACLE_HOME=$ORACLE_BASE/product/19.5.0/dbhome_1
[oracle@William ]$sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Dec 1 17:35:19 2022
Version 19.5.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.

ERROR:
ORA-12547: TNS:lost contact


Enter user-name: 

[oracle@William ]$export ORACLE_HOME=$ORACLE_BASE/product/19.5.0/dbhome_1/
[oracle@William ]$sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Dec 1 17:35:09 2022
Version 19.5.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.5.0.0.0

SQL> quit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.5.0.0.0

Note：仔细观看后面登陆的export环境变量结尾是有个斜杠

三、问题处理

以原本带斜杠的环境变量登录数据库关掉数据库，再设置没有斜杠的ORACLE_HOME环境变量再启动数据库实例即可复原

[oracle@William ]$export ORACLE_HOME=$ORACLE_BASE/product/19.5.0/dbhome_1/
[oracle@William ]$sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Dec 1 17:57:15 2022
Version 19.5.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.5.0.0.0

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.5.0.0.0

[oracle@William ]$ export ORACLE_HOME=$ORACLE_BASE/product/19.5.0/dbhome_1
[oracle@William ]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Dec 1 17:59:04 2022
Version 19.5.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1048575592 bytes
Fixed Size                  9129576 bytes
Variable Size             616562688 bytes
Database Buffers          415236096 bytes
Redo Buffers                7647232 bytes
Database mounted.
Database opened.
SQL>

Note：经测试11g只会提示连接到空闲实例，并不会报ORA-12547: TNS:lost contact

所以一个良好的习惯很重要