SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function dictGetOrDefault (alias value_first) (children 1)
     ExpressionList (children 4)
      Literal \'01681_database_for_flat_dictionary.flat_dictionary_simple_key_complex_attributes\'
      Literal \'value_first\'
      Identifier number
      Function toString (children 1)
       ExpressionList (children 1)
        Literal \'default\'
    Function dictGetOrDefault (alias value_second) (children 1)
     ExpressionList (children 4)
      Literal \'01681_database_for_flat_dictionary.flat_dictionary_simple_key_complex_attributes\'
      Literal \'value_second\'
      Identifier number
      Function toString (children 1)
       ExpressionList (children 1)
        Literal \'default\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.numbers
   Literal UInt64_3