I was reading this:
http://www.dbazine.com/mullins_onlineschema.shtml

Sounds like on DB2 V8 for z/OS you can change CHAR(n) to CHAR(n+x) with an ALTER TABLE command:

ALTER TABLE TEST
ALTER COLUMN TESTCOL
SET DATATYPE CHAR(100);

Sounds like an excellent feature! Anyone know if it's coming to DB2 for Linux/Windows/Unix? Right now it's limited to expanding VARCHARs. I'm sick of export, drop, create, import...

I didn't see it in the Stinger list either.