Integrity Of A Single Transaction Connection Over Many Active-Records

I want to guarantee isolation of my DB connection

I currently am trying this:

$additional_active_record->dbConnection = $this->owner->getDbConnection()->getCurrentTransaction()->getConnection();

$additional_active_record->db = $this->owner->getDbConnection()->getCurrentTransaction()->getConnection();

…hmmmm, please advise, is that good, too little, too much???