SELECT from Union of Structs

[Jonathan Bryant]

I've created a hive table using the AVRO SerDe's sitting on top of a schema
containing a union of records, similar to:

{ "name": "Foo",
  "type": "record",
  "fields": [
    { "name": "foo", "type": "int" },
    { "name": "details", "type": [
      { "name": "Bar",
        "type": "record",
        "fields": [{ "name": "bar", "type": "int" }] },
      { "name": "Baz",
        "type": "record",
        "fields": [{ "name": "baz", "type": "int" }] },
      ]
    }
  ]
}

How do I "SELECT foo, bar FROM table" or "SELECT foo, baz FROM table",
i.e., select the individual fields of the unioned structs?  When I "SELECT
* FROM table", it has either {0:{"bar":42}} or {1:{"baz":42}} and I don't
know how to destructure that any further.  LATERAL VIEW doesn't seem to
work for this and my Google-fu is otherwise failing me.

Thanks,
--Jonathan Bryant