How does Oracle Data Guard provide zero data loss capability?
Oracle Data Guard, with its robust data protection and disaster recovery features, is a highly effective zero data loss solution used by customers worldwide. For a zero data loss requirement even in the face of disasters, Data Guard can be configured in the Maximum Protection or Maximum Availability modes. For either of these modes, redo transport is done using LGWR, SYNC and AFFIRM. Redo data transmission to the standby databases in these modes is synchronous. This means that as transactions cause changes on the primary database, they are not committed on the primary database unless the changes (in the form of redo data) are also available on disk (in Standby Redo Logs) on at least one of the standby databases that meets the minimum requirements of the Maximum Protection/Availability modes. One important point to note in this case is that the primary database transactions do not wait till these redo changes are actually applied on the standby database – they wait only till they are av
