Can we extend the library to store it in any persistent data store

[techwizardg]

This is not an issue but asking how to do the same. Assuming a phone with 5000 contacts(i.e. today this scenario is very common with gmail syncing all emails to your phone book too), it is not good to read them every time an application needs and instead can this be read and persisted in data store like SQLLite and then use listener to look for changes in address book and update the same in SQLLite.Is this possible using ohana?

[NickEntin]

Should be fairly straightforward to do by creating a custom data provider that manages the SQLLite database and loads in the data from the address book. It could then listen for changes and update the database appropriately. You would then use this data provider instead of one of the provided ones.

I would be interested in seeing if you get a significant performance increase from this. Initially I would suppose that more of the time is spent on creating the OHContact instances than reading the data, but I haven't run tests on it, so I can't say for sure.