Kindly guide me how long the raw data from sensor is retained for local server as I think it's 1 minute updates on local server but not clear about duration of storage in local server

Hello all wanted to know how long or is there any setting governing the period for which the raw data from the sensor is retained in local server, also kindly guide as suggested in few topics to use reports widgets instead of API to view raw data(CSV) kindly guide other API’s in the apiary docs of Blynk will it be there as of now as will be using in APP Development…Thanks a lot for guidance