db link does not work due to $TNS_ADMIN

Few weeks ago I run into a very weird problem. A database link works on the server but it does not work on the client.

On the database server,

SQL> select * from dual@orcl.oracle.com;


On any client,

SQL> select * from dual@orcl.oracle.com;

Later I also found the database link does not work from sqlplus on database server if I use the tnsname.


This is really interesting. After some investigation I found out the difference is environmental parameter $TNS_ADMIN.


ps -ef | grep oracle

pxargs -p