About APEX – A developers blog

Last week I tried to install Oracle Forms 11g. This install created a new Oracle_Home on my computer, which resulted in my database not starting up anymore.
The cause of this was, that my computer did not pick up the right tnsnames.ora file anymore, but instead it picked up the new tnsnames.ora that was created during my Forms installation.

To avoid having to have multiple copies of the same tnsnames.ora file on your computer, you can create a registry key in all Oracle_Homes. This will force your computer to pick up the same file for all your Oracle_Homes and thus allow you to have just a single copy of tnsnames.ora to manage.

To do this, start the Windows Registry editor by using Start -> Run -> Regedit and find your Oracle_Homes under HKEY_LOCAL_MACHINE -> SOFTWARE -> ORACLE and rightclick on your Oracle_Home entry. Choose New -> String Value and enter the required information similar to the following screenshot (directory on harddrive may differ on your computer).

TNS_ADMIN registry entry

The registry key is called TNS_ADMIN and it’s value is the location of your tnsnames.ora file on the harddrive.
But remember to only add this key to the Oracle_Homes that do not contain your central tnsnames.ora.

I did another Whitebook (in dutch). This time the subject is New Features in the APEX 4.0 Early Adopters release.
You can find it at the Whitehorses website.

By the way; besides this personal blog I also publish articles on the blog at the Whitehorses site together with the other Oracle, Java and SOA specialists of the company. These blogs are in english. A direct link to the list of my blogs is in my profile.