Android Phone tracking

We are building an application to be able to track kids in summer campus using their phone in case they are lost. My question is, what is the best way to sync location data every-time. There are two options : 1- Sync every 5 seconds, by updating db and inserting location data every 5 seconds. If we have a lot of phones and writing to the same db, it would be very hard to manage. 2- Tracking Real-time movements of the phone, still don't have any idea on how can I do this, any suggestions are welcomed.