ORA-12154 Blues

I assigned a developer a trouble ticket from the production environment. He said he was getting errors when trying to connect and reset his password. The specific error was ORA-12154, which translates to "TNS: Could not resolve service name."

This looked like a simple problem to correct. I ensured he had the TNS_ADMIN environment variable set. I also ensured he had the right "tnsnames.ora" file on the network. That seemed strange.

After I gave up, I called in our lead DBA. He wanted to see how many Oracle homes there were on the guy's machine. There were multiple ones due to the multiple products installed. The developer could not find an Oracle Home selector. But this did not turn out to be the problem either.

The lead DBA and myself went through different ideas to get this guy running. Then I had a strange thought. What if this guy had a weird password that was screwing things up. I thought that could not be possible since we have a trigger that prevents bad passwords. However the DBA told me his profile did not enforces the password trigger. Sure enough the developer had an "at sign" character in his password. So the part of his password after the password gets treated as the host string. His logon would never work.

In the end we had a DBA reset his password. This just goes to show that an Oracle error message does not always identify the exact problem being encountered. You might need to team up with some competent individuals to figure out the problem. It might also involve thinking outside the box and trying things out.