Connectivity Problems with MDAC and Oracle 9 client

It appears that MDAC does not recognize the Oracle 9 client when installed and instead recognizes it as an Oracle 7.x client. As such, the registry settings are entered incorrectly and it is not possible to connect via MDAC from certain applications (in my case, Access 2000)

I encountered the error when trying to connect to an Oracle database from a Windows 2000 Professional machine through Microsoft Access 2000. The machine was installed with only the Oracle 9 client (no prior versions of Oracle ever existed on the box). Specific versions were Windows 2000 Professional SP3, Office 2000 SP2, Oracle Client 9.2.0.1.0 and MDAC 2.7. Back end database that I was connecting to on another server was Oracle 8.1.7.

The MDAC installation appears to set the following registry settings incorrectly. See Microsoft KB article Q264012 for similar problems with MDAC and Oracle 8. I was not able to find any mention of problems with MDAC and Oracle 9 in the Microsoft KB or at metalink.oracle.com, so I am posting the information here.

On a Windows 2000 machine, the following registry settings appear to be set by default and are incorrect:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\MTxOCI]
"OracleXaLib"="xa73.dll"
"OracleSqlLib"="SQLLib18.dll" "OracleOciLib"="ociw32.dll"

Change them as follows:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\MTxOCI]
"OracleXaLib"="oraclient9.dll" "OracleSqlLib"="orasql9.dll"
"OracleOciLib"="oci.dll"

For other operating systems, see the Microsoft KB article Q264012 for the correct registry paths.

Hope this helps. Received on Thu Nov 14 2002 - 15:28:33 CST