SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function substr (alias a) (children 1)
     ExpressionList (children 2)
      Literal \'aaaaaaaaaaaaaa\'
      Literal UInt64_8
   ExpressionList (children 1)
    Identifier a
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier a