Can I increase the length of a column without affecting the data??

Only if it is a varchar.

Andy

not sure with which version of db2 ....V8 or V9 you can use altobj stored procedure ...give it a try ...

ALTER TABLE KCDWHDUT.T9PST
ALTER COLUMN PRCES_PGM_NM
SET DATA TYPE CHAR(50)

I tried this and it seemed to work and NOT affect the data

Careful with ALTOBJ: it may not be needed in this case.

What do you mean with "not affect the data"? Did you verify that the results being returned when you query the table will have more spaces padded to the end? If that's the case, everything is fine.

Additionally, you may want to run a REORG on the table.

(At least, when you are on DB2 v8 for z/OS or later; not sure whether this is possible on other platforms.)

Suppose the original datatype is CHAR(100); the data will be preserved, that is,
all varchar fields will have a length of 100 (i.e., possibly with blanks at the end), but after the ALTER, updated or inserted fields may be of lengths between 0 and 1000. (Or chose anything else than 1000.)
Similarly, a CHAR(100) or a VARCHAR(100) may be altered into a CHAR(1000); the new length must be at least the old length.