title: DB record versioning
body: <p>I have following task: There is DB which contains all the data. We have some scrappers which update DB with newest data from some resources(external sites/systems) and we need to implement following logic: one type of users should see latest data but another type of users should see data which was in DB 15 minutes ago. So my initial solutions was to have 2 DB and sync them each 15 minutes but are there any other solutions to implement that?</p>
  
  <p>Thanks,</p>