Since this is JavaRanch, I presume you are using the
Java SDO API rather than the C++. The performance characteristics in Java and C++ are generally the same, unless you are dealing with very large DataObject, where C++ has a performance advantage due to the way memory allocation works in C++.
One of the most important factors in the performance of an SDO runtime is the XML parsing performance.
What type of data are you dealing with?
Each type of data requires a different Data Access Service - and each will have different performance characteristics.