Currently we can able to export Activity, Contact, Account related data out from Eloqua via standard Data Export feature. It would be great if Eloqua can include CDO as well in this list.
There already is an option from the CDO's itself to export them.
I'm assuming OP is looking for a way to schedule the exports, which is what brought me to this page.
You can export data from CDO or CDO with Contact fields, but this option manual , we can not schedule it as of now. That will be a good option if Oracle brings an automated job to export CDO data to SFTP area.
Vote up, to export a list of CDO records is something you don't want to cross in your entire life, API calls, field lists, definitions...