Any oracle10g driver is available for QT3
Looks like it's a QT4 business now.
I would contact the Oracle experts for a driver, or change to MySql. (Or change to QT4.5 if that is a possibility).
2008-02-07, I haven't been able to find any reason for the driver to leak cursors within Designer, as my testing with my own code didn't leak any cursors. I'm going to chalk this up to a bug in how Designer handles its database plugins. I released a slightly updated version of the driver which explicitly deallocates statements (and therefore cursors) when the result set goes out of scope, even though Designer still causes the Oracle server to report a cursor exhaustion. I've marked the driver as being in transition between an alpha and beta stage, so try it out and report your results back to the SourceForge forums.
and then:
I'm going to begin porting the driver to Qt 4. Hopefully this will go a lot faster than the original Qt 3 implementation.
QT3 is like abandonware right now, hehe.