I am developing a mobile app and it performs too much work. (For me I think) Generating reports from my local database data takes up to 2 hours. I'm not sure if it's my algorithm, or it's the phone's limitation.
My question is, up to what extent of computation must be done by the mobile app? When do I know if I need a web server to do the computations for the app?
Additional Information: My mobile app gets tickets from API and totals ticket metrics per month, and gets the average of each metrics per month.