Mysql radius.radacct trying to clean up

Hi, Our radacct table in mysql reached 11 million rows and we don't need this information. Would it be safe if I stopped FreeRadius, mysql: truncate radius.radacct; started FreeRadius? How would this affect the active sessions with Radius (e.g those who had accounting records sent back after the table had been truncated )? Versions: freeradius-mysql-2.1.12-1.el6.x86_64 freeradius-utils-2.1.12-1.el6.x86_64 freeradius-2.1.12-1.el6.x86_64 Kind regards, Sophie