This week's book giveaways are in the Refactoring and Agile forums. We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line! See this thread and this one for details.
UserA is updating a record into db, but at the same time UserB wants to check the old recored from the same db. If a userA updated a record, then how can a userB can see the old record, because the old record is overwrited in the db.