Vespa YQL parameter substitution fails with 400 when passing a JSON object in POST query
Root cause, diagnosed by maintainer pangwangshu: a query POSTed as JSON has its nested objects flattened into single-level dotted properties by Json2SingleLevelMap (this is what makes "ranking": {"profile": ...} work). So "q_terms": {"7128": 34, "2622": 18} becomes q_terms.7128 and q_terms.2622, leaving no q_terms pro…
Problem outcome: unknown