Right now, when some fields of kDBItem object are changed and kDBItem::Update method is issued then all fields are put into UPDATE sql and not only ones, that were changed.
I'm proposing to add 2nd optional parameter (1st parameter is $id) to kDBItem::Update method to allow specifying fields, that should only be updated in database. Also only these fields will be overwritten in kDBItem::OriginalFieldValues array.
This way there is still way to detect change in field values, that were not specified to kDBItem::Update method.
Ready for testing.