SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 4)
    Identifier arr2
    Identifier arr2.size0
    Identifier arr2.size1
    Identifier arr2.null
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier subcolumns