SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Identifier i
    Identifier col1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 4)
          ExpressionList (children 3)
           Identifier i
           Identifier a (alias col1)
           Identifier a (alias col2)
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier tab
          ExpressionList (children 1)
           OrderByElement (children 1)
            Identifier i
          ExpressionList (children 2)
           InterpolateElement (column col1) (children 1)
            Function plus (children 1)
             ExpressionList (children 2)
              Identifier col1
              Identifier col2
           InterpolateElement (column col2) (children 1)
            Identifier col2
