mysql changing field definition for an existing db.

[Alan Munday]

 From the README.sql-mysql:


"Instead of declaring a time_iso field in table msgs as a string:

   time_iso char(16) NOT NULL,

one may want to declare is as:

   time_iso TIMESTAMP NOT NULL DEFAULT 0,

in which case $timestamp_fmt_mysql *MUST* be set to 1 in amavisd.conf
to avoid MySQL inability to accept ISO 8601 timestamps with zone Z
and ISO date/time delimiter T; failing to set $timestamp_fmt_mysql
makes MySQL store zero time on INSERT and write current local time
on UPDATE if auto-update is allowed, which is different from the
intended mail timestamp (localtime vs. UTC, off by seconds)"


Change this be changed on a live database without a problem?


Thanks

Alan