New in 12c: PDML possible for inserts on non-partitioned table with SecureFile LOB
In the past, parallel DML (PDML) has been possible for Securefile LOBs only when the table is partitioned. Starting in 12c, inserts can be executed in parallel for non-partitioned tables containing a SecureFile LOB. The Oracle documentation is being updated to reflect this change. See blog post "Parallel DML on Tables with LOB Columns" in the The Data Warehouse Insider for details.
https://blogs.oracle.com/datawarehousing/entry/parallel_dml_on_tables_with