Can dimension sizes be changed in FDQM?

We are finding that the column sizes of the attribute dimensions are falling short of the length capability we want to load.  One example is Desc1 and Desc2.  These are defined as 75 characters however, the source system we have allows 240 characters.  Can we increase the size of these fields without issues?  Simply alter table command to change or would there be much more involved?
Any ideas?  The business goal is to enable not only the Desc1 and 2 but also to enable Attr 1 thru 5 and increase the size to match what the source system allows.  That way users would see the full descriptions (attributes) when they drill to detail.