Change JDBC driver used by OC4J

Question

Hi all,
I did some testing of the different Oracle JDBC driver classes -- including "classes12.zip", "ojdbc14.jar" and "classes12dms.jar" -- in a plain old java class (nothing to do with OC4J). It seems to me that the "classes12.zip" file gives the best performance, so I was wondering if it is a good idea to make OC4J use this driver (instead of the "classes12dms.jar" file). If this is a good idea, then how can I make OC4J use the "classes12.zip" file (instead of the "classes12dms.jar" file) ?
For your information, I am using OC4J stand-alone 10.0.3 on SUN [sparc] solaris 9 with Oracle 9i (9.2.0.4) database and java version 1.4.2_02.
Thanks (in advance),
Avi.

Answer 1

Hi all,
I did some testing of the different Oracle JDBC
driver classes -- including "classes12.zip",
"ojdbc14.jar" and "classes12dms.jar" -- in a plain
old java class (nothing to do with OC4J). It seems to
me that the "classes12.zip" file gives the best
performance, so I was wondering if it is a good idea
to make OC4J use this driver (instead of the
"classes12dms.jar" file). If this is a good idea,
then how can I make OC4J use the "classes12.zip" file
(instead of the "classes12dms.jar" file) ?
For your information, I am using OC4J stand-alone
10.0.3 on SUN [sparc] solaris 9 with Oracle 9i
(9.2.0.4) database and java version 1.4.2_02.
Thanks (in advance),
Avi.gday again Avi -- funny to see you posting questions instead of answering them!
OK, here's the scoop.
In the releases of the product to date (including the current developer preview) we've hardcode the JDBC class library (classes12dms.jar) into the Class-Path setting in the Manifest.mf file of the oc4j.jar file. This basically makes the one JDBC library load at the container level and is therefore used by all applications running on the product. This is done since some of the classes which are loaded by OC4j at the container level have a dependency on classes in the JDBC library, so they need to be available.
The only way to change this is to :
a) overwrite the classes12dms.jar with the the JDBC library you want to use -- ie rename the one you want to classes12dms.jar and put it in the directory where classes12dms.jar currently resides.
b) open up the Manifest.mf in the oc4j.jar file and alter the Class-Path so it points to JDBC lib you want to use.
I can't comment authoritavely on the supportability of either of these two tasks, but I suspsect that doing either of these would put you into an unsupported mode.
But that doesn't concern you since you're running with a developer preview anyway ;-).
The good news is that with the production release (or even another developer preview update) we'll have in place our new shared libary model. This will enable us to separate in a very clean way what is a system library and what are application libraries. We'll be able to setup and configure libraries that are available to applications which will not conflict with any libraries that are loaded at the container level. The new libs will be able to be shared by all or any subset of deployed applications if needed. It's quite an elegant and very powerful feature.
So hack around today, but look forward to our next update of the 10.0.3 (which has recently be re-versioned to 10.1.3 for consistency across Oracle) release.
cheers
-steve-