ORA-14265: data type or length of a table subpartitioning column may not be changed

When you want to modify partition table' s key columns.

sample

1 - create partitioned table with subpartition.


SQL> CREATE TABLE vty_log
    (tarih        DATE,
    program       VARCHAR2(6),
    pcismi        VARCHAR2(12),
    mesaj         VARCHAR2(2000),
    boyut         NUMBER(10,0))
  PARTITION BY RANGE (TARIH)
  SUBPARTITION BY HASH (program)
  (
  PARTITION vty_log_201201 VALUES LESS THAN (TO_DATE(' 2012-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
  LOGGING
  (
  SUBPARTITION vty_log_201201_P1,
  SUBPARTITION vty_log_201201_P2,
  SUBPARTITION vty_log_201201_P3,
  SUBPARTITION vty_log_201201_P4
  )
  );

2- try to modify subpartition column

SQL> alter table vty_log modify program varchar2(10);

*

ERROR at line 1:

ORA-14265: data type or length of a table subpartitioning column may not be changed 

you have to drop/create table to achive this problem.

You can create non-partition table for each partition which has same name with partition

and exchange partition 

or

If have enoguh downtime you can export/import with orjinal table. 

or

you can create dummy table desired structure and you can insert/select/rename.