If the combination of Oracle DBMS + APEX - allows us to work well with formalized data, Drupal is designed to work with any content.
Drupal is free open source software, but it is very powerful system. Ideology within it is intended for programmers. It means that a secretary can not create a website. Nevertheless anybody can enter content without problems. But about development you should ask professionals of course.
Oracle has also a similar system - Oracle WebCenter, but it is too expensive I think.
Drupal is a scalable system. There are more than 6000 modules for Drupal 7, which often allow you to quickly gather the necessary basis for your system. There are a lot of very large sites that are implemented on Drupal (for example, web site of the White House).
Our expertise in Drupal is well known in Russia
You can read reviews and buy this book in OZON web-store - http://www.ozon.ru/context/detail/id/6146705/.
Alexey Chernykh is an author of one of books about Drupal 7, which was printed in 2011.
Read the book. All was written inside...