[iPhone] Store Application Data

Question

I am need to store some application data locally on the iphone. The data, periodically, will get updated from a server (web service). The user will not be able to change the data. There is some Parent/Child relationship on the data but not very complicated (for example a Contact, has multiple addresses and multiple phone numbers). One of the requirements is to be able retrieve all addresses for a specific contact (using the example above).
What is the recommended storage facility to store the data? Can I do this using a .plist and replace the whole file from the server? or is it better to use sqllite and do insert and update commands to update the data? Any other suggestion?
Thanks

Answer 1

NSDictionary is designed to read and write plists, so I think it's the natural choice unless you're talking about so much data that you'd begin to see a performance problem without an index. At that point you'd want to consider sqllite. I can't tell you where the cross over might be, but an index generally isn't worth the overhead until it takes more than 10,000 comparisons to find something.
A NSDictionary solution is really easy to code, so try that first and see if you have any performance or memory problem. If you're no where close to 10,000 records, I think you'll be happy with it. If you're planning for a million records it might be another story.
The problem with replacing the entire file from a server is that the plist format isn't very robust. Although the syntax is very simple, one error can make the entire file unreadable. Therefore you'd really need to trust the server. At the very least I would make a temp.plist and see if NSDictionary can read it before committing to it.