data_type

data_type 
      ::= 
      char_string_type 
      [ "character" "set" char_set_spec ] 
      | national_char_string_type 
      | bit_string_type 
      | num_type 
      | datetime_type 
      | interval_type 

This rule is called by

-> cast_target
-> column_def
-> domain_def
-> parameter_decl