rsync output -vv differs with dry-run option

[Claas Hilbrecht]

I'm trying to figure out if a file has changed since the last rsync call. I 
use the following command line:

rsync -cvv /mnt/xxx/vol1/dbase/100/kunden.dbf /mnt/label | grep "^total: " 
| sed -e 's/.* data=//'

This gives a 0 if the file is unchanged and the file size if the file has 
changed. Adding the "dry-run" option "n" to the command line always gives a 
0. I wonder if this is a expected behaviour?

-- 
 Claas Hilbrecht
 http://www.jucs-kramkiste.de