Changing DB type from MySQL to MySQLi after installation
 

If I was originally running mysql database type* then I change the config.php to mysqli instead of mysql (dbtype)* but I did this after an install (i.e. when I had members & threads etc) - does this cause any difference? Does the dbtype have to be declared at installation then kept the same?

I know vBulletin has database handlers which is why I presume changing the dbtype mid-way won't affect anything* i'm just looking for some clarification.