Result set 1:
columns {
  name: "key"
  type {
    type_id: STRING
  }
}
columns {
  name: "column1"
  type {
    type_id: STRING
  }
}
Result set 2:
columns {
  name: "key"
  type {
    type_id: STRING
  }
}
columns {
  name: "column1"
  type {
    type_id: STRING
  }
}
