ios - Updating core data performance -

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i'm creating app uses core data store information web server. when there's internet connection, app check if there changes in entries , update them. now, i'm wondering best way go it. each entry in database has last updated timestamp. of these 2 more efficient:

  1. go through entries , check timestamp see entry needs updated.
  2. delete whole entity , re-download again.

sorry if seems obvious question , thanks!

i'd option 1 efficient, there case downloading (especially in large database large amounts of data) more efficient downloading parts need.


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