OneIM upgrade from 8.1.1 to 8.1.4

We are using version 8.1.1 currently and migrating to 8.1.4,
We are going with that were going through documentation, in database permissions section, it is written -
"If you want to switch to granular permissions when you update from 8.1.x to version 8.1.4, contact support. To access the Support Portal, go to ">"
We need to undersand what exaclty needs to be done for the same.Do we need to get any more permissions for the service accounts which is being used for connecting to the database (windows authentication is in place).

Thanks & Regards