This is a very popular question, but I don't know the answer. I'd search the cmp forum and both mailing lists. My understanding is the basically the Oracle drivers don't work, and working around their limitations is difficult.
There are problems with Oracle 8 JDBC drivers and LOBs, and you have to write Oracle specific code to use them. So much for standards...
Apparently Oracle 9 has fixed this but I haven't used it for LOBs personally.
I have reied to make Jboss/Oracle blobs work with Oracle8 and 9. No workie. The OCI drivers apparently do not work with JBOSS at all. Tried tweaking the standardjbosscmp-jdbc file to get away from Blobs, but no luck. Also tried JBoss versions 3.0.0 , 3.0.1 and 3.0.2 . Any ideas????
As I said before, ask on the cmp forum. As far as datasource configuration is concerned, they work fine.
It may be possible to write an oracle specific jca-jdbc wrapper extending the appropriate existing wrapper classes to work around the laughing-at-the-spec behaviour of the oracle drivers, but first you need to find out how to work around them.
If anyone wants Oracle/LOB information:
( you may need an OTN logon to see some of the pages on the oracle web site. )
http://otn.oracle.com/tech/java/sqlj_jdbc/pdf/a96654.pdf ( for Oracle 9 )
http://technet.oracle.com/doc/oracle8i_816/java.816/a81354/oralob2.htm#1057908 ( has Oracle 8 stuff )
There should also be sample code in your Oracle installation.
I don't know about CMP, but if you are just getting drivers or data sources from JBoss to use as normal JDBC, you can use the current jca-jdbc wrapper, as the Blob code should be in your client code.
To avoid problems I changed the standardjaws.xml in
<!-- Change this from BLOB to RAW(255) if you know your
serialized object will be <= 255 bytes -->