I was recently asked to set up a linked server to Oracle and this is something I have done in the past. No problem I thought. To connect to Oracle you need the Oracle Data Access components and I has asked the Oracle DBA if they were installed. He said yes and that everything was configured on his end. I referenced David Browne’s blog for a quick review and ensured the Oracle directory was in the PATH variable.
I then proceeded to create the linked server got the following error–ORA-12514:TNS:listener does not currently know of service requested in connect descriptor
There ended up being two issues–the first being, the TNSNames.ora file did not contain the entry for the database I was trying to connect to. I guess the Oracle DBA didn’t think that was part of his setup. Secondly, for some reason, the Oracle_Home variable was not set–it was blank. I am not sure how that is possible; however, once I put the correct path in, I was golden and off and running.