Interesting few phone calls this morning, the back story:
We upgraded a database from 22.214.171.124 to 10gr1.
The core group of users tested it thoroughly with no problems, everything was signed off on, the upgrade went with a hitch and everything worked great. For less than 1 business day.
The system has an export facility to the local government body of data we collect. The GUI creates an XML file that the users then upload to the government via a web site. Some users started complaining of getting ORA-0600 errors when they try to create their XML file. Other users were not having any problems at all. This had been tested and signed off on. The application support people had tried and could not find a problem and they could successfully create the files for the users. I started going through metalink trying to find any related items to the upgrade that we might have missed. I could find nothing, but I stumbled across a similar ORA-0600 error 16608 with a oracle 8 client trying to connect to a oracle 10g database. I didn't think that was applicable, but I looked into it anyway. Every single person getting the problem has the oracle 817 client installed because they use an older application that requires it. The 10g application GUI defaults to this home. After working with the vendor, we could not force the GUI to use the oracle 9i home on the PC's. We installed the instant client, to no avail. The application works great with the 9i client so we had decided to slowly install the 10g client as it was needed.
I read through forum entries and the like on using multiple oracle clients on the same PC and none of the suggestions worked. If I removed the Oracle 8 settings from the path, the 10g application worked, but the 8i application did not work. If I moved the oracle 8 settings to the end of the path, the 10g application worked, but the oracle 8i application did not.
I did some head scratching, and came up with the following for starting the 10g application.
call "c:\program files\10gapp\10gapp.exe"
That works very well.
If anybody out there has a better way, please comment as this is now in use on about 100 PC's throughout the company.