Android - Retrieving data from remote Database efficiently

I am working in an Android project designed for doctors. Doctors are required to authenticate when they open the app for the first time.

This authentication process is done through a HTTPS connection, using PHP code in the server-side that returns JSON code to the app, letting it know if the connection has been successful and, if it is the case, it also returns that doctor's list of patients. Let me show a piece of JSON code that would be returned in case of a successful log-in (for some reason, since I don't have 10 reputation points, I cannot post an image, so please navigate to the link below):

http://ift.tt/1OSZs7y

Obviously, if the log-in were unsuccessful, the "listOfPatients" attribute would carry no data. After the server generating this JSON code, the app would simply read through it using a JSON Parser.

Now imagine the doctor doesn't have just 3 patients, but 100 patients. And each patient doesn't have just 3 attributes ("Age", "Phone", "Smoker") but dozens of them appropriately nested where required. We would then have a somewhat large (but maybe not too complex) JSON code to read through.

In this project I am designing the Client code (i.e. the Android App), whereas the Server code is written by other guy. He is asking me how I'd like the server code to be written in order to facilitate the "Android Client - Server" interaction and achieve the best, smoothest user experience possible.

I answered (this is the really-short version of my answer; don't concern about the server-side-code security since it is not the goal of this question):

1. Create a login.php that allows for POSTS queries. My App would send "user" and "password" and the server would compare it with the database.


2. The server would then generate appropriate JSON code depending on the success of the doctor's log-in request.


3. The Android app would simply parse this JSON and display it to the user in form of list-views, and so on (the way I display this data to the doctor does not matter here in this question).

I was wondering two things:

1. Knowing that the JSON will contain hundreds of attributes, how efficient is this code? Is there a better way to achieve this functionality? How would you do it?


2. The vast majority of these attributes' values will change on a daily basis (for example, "bodyTemperature" or "bloodPressure"). Furthermore there will be "importantNotifications", where patients would notify their doctors in case of an emergency situation. I don't think it would be efficient to go through the entire process ("server create JSON ==> client read JSON ==> client display JSON") over and over again, minute after minute, hour after hour, day after day. There must be a better way to do it (maybe local storage? I would then have to discern which attributes to read only once a year ("age"), once a month ("phone"), once a day ("bodyTemperature") or every 30 minutes ("importantNotifications"); How could I then discriminate which values I'd need to read from the JSON in each session?)

Thanks for your time.