What is data synchronization and best practice of data sync?
This video helps you
https://learn.outsystems.com/training/journeys/odc-2018-mobile-551/offline-data-sync-best-practices/o11/2498
also refer to this document
https://success.outsystems.com/documentation/11/building_apps/data_management/mobile_performance_strategies_and_offline_optimization/implementing_offline_sync/?_gl=1*1r02c3d*_gcl_au*MTQ4MjA2NTcyNS4xNzYwNDIzNTY0*_ga*MTk2OTk2MjU4OS4xNzYwNDIzNTY3*_ga_HGKNZZMWJS*czE3NjA0NDU3MDkkbzUkZzEkdDE3NjA0NDY0ODYkajU4JGwxJGgyMDI3OTI4NTgw*_ga_G11QMS1MBT*czE3NjA0NDU3MDgkbzUkZzEkdDE3NjA0NDY0ODYkajU4JGwwJGgw*_ga_ZD4DTMHWR2*czE3NjA0MjM1NjYkbzEkZzEkdDE3NjA0NDY0ODYkajU3JGwwJGgw