SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier summing_merge_tree
   ExpressionList (children 5)
    OrderByElement (children 1)
     Identifier d
    OrderByElement (children 1)
     Identifier a
    OrderByElement (children 1)
     Identifier x
    OrderByElement (children 1)
     Identifier y
    OrderByElement (children 1)
     Identifier z
