The sys_user and sys_group table holds the user and group records and permissions for everything in the ispconfig interface. The client table is only there to store the clients address and some limits. This is splitted to have the ability to provide more then one login per client / reseller. If you think of larger corporations which have more then one administrator and dont want to share the same username and password for all administrators.
Sorry for opening old topic, hope it's ok. You said the client table is there only to store personal details about client. I need to update reseller username and password directly in database. Is it ok to edit just fields passwort and username in sys_user table? I am confused because in client table there are also fields username and password. Do I have to update them too? EDIT: Now I noticed the password reset doesn't work until I edit these values in client table. Can you please explain why are these values duplicated?