Having two ODP.NET (ODAC) versions in the same server
Some months ago, a colleague of mine installed ODAC 11.106.21 in a server using XCOPY and then he developed many applications that use this client without problems (in test and production windows servers).
Past week, I developed an application under ODAC 11.1.07.20. When I asked him to install these new ODAC version using XCOPY in a different folder and then include my application in the test server, he answered me that I should use ODAC 11.106.21 because he could have troubles with his applications.
So I would like to know:
1) If it is really possible to have two different ODAC versions in one server.
2) If the answer is positive, how can I firmly ensure to my colleague that he will not have troubles with his applications?
3) If the answer is positive, is this necessary to do some kind of configuration in the server?
Thanks!!
Answer
You can have multiple versions of ODAC on the same machine, but there are several things to be aware of with regards to which version will be used by each application. This actually applies to all assemblies.
- in Visual Studio, if you set Specific Version = True on Oracle.DataAccess.dll, then that application will not use any other version and must be able to find the version it was built against.
- whether you deploy the DLL with your application or expect it to be in a certain place or in the GAC.
- there is a specific search order for finding dependent DLLs, and it's quite involved, so read this MSDN topic.
The short answer is that there are two easy ways to make sure your application uses the exact version of Oracle.DataAccess.dll you want it to (this applies in most cases where everything else is default):
- Set Specific Version to True;
- Deploy the DLL with your application and have it reside in the application directory, OR ensure that the DLL is in the GAC.
In your specific case, your colleague may have a valid concern: If his applications which are currently installed are getting Oracle.DataAccess.dll from the GAC, and he didn't set Specific Version to True, then when you install the new ODAC, his applications will start using it (I'm assuming the new Oracle.DataAccess.dll will be installed in the GAC too),