OpenACS requires stored JAVA procedures in acs-content-repository to deal with STRING to BLOB and such things (just go to /packages/acs-content-repository/java and take a look). I assume you can do this now with dbms_log PLSQL functions or util_raw, but I am no Oracle guru and I gave up after digging around for some time.
Getting Oracle XE to run would also be great as installing it is as easy as running PostgreSQL if you follow these instructions: http://www.cognovis.de/developer/en/oracle-xe-installation
