{
  "version": 1,
  "entity": { "type": { "constant": "viewer" }, "id_column": "viewer_id" },
  "event_type": { "from_column": "event_type" },
  "timestamp": { "column": "occurred_at" },
  "event_id_column": "event_id",
  "attributes": [
    { "column": "genre" },
    { "column": "device" },
    { "column": "minutes_watched" },
    { "column": "plan" }
  ]
}