Is not more good execute the query for change and not reset and load new structure always? with actual delete external add also if good and can have a problem also with clean ispconfig in some case of import data or i'm worng? Sorry for my bad english if not explain good^^''
I think the current system is working pretty well, we see only a few reports about problems here which could be fixed easily while we have many thousands of updates. Nevertheless, I've already planned to introduce some kind of incremental database updates starting with the update from ispconfig 3.0.2 to 3.0.3. But this also has some drawbacks as we will see an increase of problems due to inconsistent table structures then e.g. that a field is available in the interface but values never get stored in the db as the field is missing there. Also you can update at the moment from any ispconfig 3. version to the latest version without having to install all versions that had been released between these releases.
On my server, I installed ispconfig (from ovh installation), but I had the roundcube webmail by this way : http://howtoforge.com/forums/showpost.php?p=213239&postcount=20 I think this won't work for me because it changes the mysql table, isn't it ? Moreover, I changed some things in postfix main.cf configuration and pureftpd too, like apache2.conf or other files like this .. Every one of this file would be overwrite ? I'm sorry about my mix-up in the ispconfig changes...
This should be no problem as it does not change the table structure. It just inserts a record into the table which is ok. The installer asks you if it should reconfigure services, if you choose no, it will not overwrite any config files. If you changed a lot of files, select no and in case that something is not working afterwards, you will have to compare your configuration with the code in the ispconfig installer and the template files.