aggregates over functions almost work

[galkk]

Seems like the fix should be relatively simple, given that it generates aggregation correctly and only return in generated script is missing

POST /_opendistro/_sql/_explain
{
  "query":"""SELECT max(log(FlightDelayMin))
    FROM kibana_sample_data_flights
    GROUP BY DestCountry, dayOfWeek
  """
}

{
  "from" : 0,
  "size" : 0,
  "_source" : {
    "includes" : [
      "MAX"
    ],
    "excludes" : [ ]
  },
  "aggregations" : {
    "DestCountry" : {
      "terms" : {
        "field" : "DestCountry",
        "size" : 200,
        "min_doc_count" : 1,
        "shard_min_doc_count" : 0,
        "show_term_doc_count_error" : false,
        "order" : [
          {
            "_count" : "desc"
          },
          {
            "_key" : "asc"
          }
        ]
      },
      "aggregations" : {
        "dayOfWeek" : {
          "terms" : {
            "field" : "dayOfWeek",
            "size" : 10,
            "min_doc_count" : 1,
            "shard_min_doc_count" : 0,
            "show_term_doc_count_error" : false,
            "order" : [
              {
                "_count" : "desc"
              },
              {
                "_key" : "asc"
              }
            ]
          },
          "aggregations" : {
            "MAX(log_1=def log_1 = Math.log(doc('FlightDelayMin').value)/Math.log(Math.E))" : {
              "max" : {


MISSING RETURN HERE, THAT"S IT
                "script" : {
                  "source" : "def log_1 = Math.log(doc['FlightDelayMin'].value)/Math.log(Math.E)",
                  "lang" : "painless"
                }
              }
            }
          }
        }
      }
    }
  }
}

[dai-chen]

The issue has been fixed in new query engine (which is experimental and disabled by default). You can enable it to preview by changing the plugin setting: https://github.com/opendistro-for-elasticsearch/sql/blob/master/docs/user/admin/settings.rst#opendistro-sql-engine-new-enabled. Thanks!