What does the 

题目

What does the SCN represent?()  

  • A、 The system change number, which is a point in time relative to transactions within a given database.
  • B、 A number that represents time. Thus, at 1300 hours, the SCN is the same on all databases. 
  • C、 The security change number, which represents the security code that is needed to access any database structure.
  • D、 A conversion factor that converts internal database time to external clock time.
  • E、 UTC time in the database,providing a standardized way of tracking time in Oracle.