To obtain the query execution plan for a query as executed by Content Platform Engine for Oracle, use the technique that is described here. This technique comes from Oracle support.
COLUMN id format 999
COLUMN pid format 999
COLUMN operation format a25
COLUMN options format a20
SET linesize 150
SET pagesize 999
SELECT distinct hash_value, sql_text
FROM v$sql
WHERE lower(sql_text)
LIKE lower('%query portion%');
SELECT distinct id, parent_id AS pid, lpad (' ', depth) || operation operation, options, object_name, cost, bytes
FROM v$sql_plan
WHERE hash_value = <hash value from previous query> order by id;