Question: what is the latest version of oracle database
[{'answer': 'Oracle Database 18c', 'provenance': [{'wikipedia_id': '323725', 'title': 'Oracle Database', 'start_paragraph_id': 27, 'start_character': 167, 'end_paragraph_id': 27, 'end_character': 186, 'bleu_score': 1.0, 'section': 'Section::::Oracle Database deployment.:Database editions.\n'}]}]