Blackberry | Keeping local Persistant Storage up to date with remote database

Question

Hi,
I'm developing a blackberry application to remotely access an external customer database.
Selected employees can change customer entries via a webinterface accessible in our intranet.

I don't want the blackberry to contact the database on every request, so I built in a local storage, which stores the top 50 selected customers of the blackberry user.

What the best practice to keep both records in sync? I thought about creating an hashcode of each record to reduce the datasize to transfer (and though the energy necessary to transmit it). Can anyone here tell me what they do, to reduce requests by a mobile device?

Thanks, rAyt

Answer 1

In a couple of different situations I've added a created/modified timestamp to each record. On a successful sync with the server, you note the last server time, store it on the client, and on the next sync only get the records (if any) that have changed since the last one. This will reduce data but you may still have to deal with records that were changed on both client and server since the last sync.