Since renaming is a relative pain in DBF and SQLite,
I have written a new script v.db.renamecol. To use it
be sure to update db.describe, too, from CVS.
Usage example Spearfish:
g.copy vect=roads,myroads
v.info -c myroads
INTEGER|cat
CHARACTER|label
v.db.renamecol myroads col=label,roadtype
v.info -c myroads
INTEGER|cat
CHARACTER|roadtype
Tested with PostgreSQL, too.
Cheers
Markus
PS: I didn't test with MySQL - please let me know if it should fail there.