DB2 9 for z/OS

I have a table with a ROW CHANGE TIMESTAMP column on it that was defined as GENERATED BY DEFAULT. Is there anyway to alter this column and change it to GENERATED ALWAYS? I thought the following might do it:

ALTER TABLE "TDKGROUP"
ALTER COLUMN "SYS_GEN_TMSTMP" SET GENERATED ALWAYS;

But I received the following:

DSNT408I SQLCODE = -20180, ERROR: COLUMN SYS_GEN_TMSTMP IN TABLE
ASLDB2.TDKGROUP CAN NOT BE ALTERED AS SPECIFIED

I think this alter may only work on generated identity columns. Any suggestions? I'm trying to avoid dropping the table.

gwilper, I am not sure you have any other choice. According to Info center topic DB2 V9.1 - DB2 SQL - ALTER TABLE:

A column cannot be altered if any of the following conditions are true:

The column is defined as a row change timestamp column

You will have to scroll down a bit to get to the text on ALTER COLUMN column-alteration.

You have to define column SYS_GEN_TMSTMP Timestamp not Null with default.

Then, when you insert values into TDKGROUP use this simple query:

Could be also something like this (DB2 V9):

Kara