The database schema defined in dspace/etc/oracle/database_schema.sql contains some artifacts that were dropped from the PostgreSQL schema in past releases. They need to be removed from Oracle's schema to bring them back to parity. They are:
"History" table (delete it)
"HistoryState" table (delete it)
"mets_bitstream_id" column of "Bundle" table (delete it)
Change "MetadataValue.text_lang" to varchar(24) to match PostgreSQL.
Patch is forthcoming.