"get rid of Oracle"
Sure, but replace it with what ?
I cannot imagine the sheer volume of data stored and managed in a government-level group of Oracle databases, even taking into account the fact that there is no oversight or global planning of any kind (good one there, way to ensure economies are impossible).
You don't just get rid of Oracle. You need to find a suitable substitute, redesign the applications, create a parallel environment, migrate the data onto said parallel platform, design a test suite to validate the transfer and test the new environment and validate it.
When all that is done, you can start migrating the users. You'll be doing that bit by bit, so as not to have everything blow up in your face with the inevitable unexpected complications that will arise.
Just planning this kind of thing will be a major project which will require external expertise.
Hmm, do I smell the presence of yet another pork barrel for yet another vast, government-wide IT failure ahem, project ?