ORA-12547: TNS: lost contact

 

ORA-12547: TNS: lost contact

 

 

Today while working on 19c upgrades I faced below oracle-error ORA-12547 TNS: lost contact

 

After checking few oracle metalink documents, I came to know that the issue can be due to multiple reasons like as few below.

•  Wrong permission of the executing Oracle binaries.
• Oracle binaries not linked correctly with linux OS.
• Listener can be in hung state.

I checked for above issues,  but in my case everything was good and still I was getting the same error.

So after few hit and trial I saw that when the forward slash is appended to the end of the ORACLE_HOME environment variable.

The connection to the database is successful.

In below screenshot we can see that there is no forward slash at the end of the ORACLE_HOME environment variable. And we get the error.

 

While In below screenshot we can see that when forward slash is appended at the end of the ORACLE_HOME environment variable.

The error gets resolved and we are able to connect to the database.

 

I hope this document will help J