This will DESTRUCTIVELY UPDATE all your data. Make sure you have backups,
use at own risk, yada yada.
+* Note: your database may not actually delete the changed data from the disk
+ when you update fields. For Postgresql you will need to VACUUM to delete that
+ And even then, your operating system may not delete the data from the
+ disk. Properly getting rid of these traces is left as an excercise to the