The following text describes failover.gif.
This illustration shows a two-site Data Guard configuration after a system or software failure occurred. In this figure, the primary site (in San Francisco) is crossed out to indicate that the site is no longer operational. The Boston site that was originally a standby site is now operating as the new primary site. Applications that were previously sending read/write transactions to the San Francisco site when it was the primary site are now sending all read/write transactions to the new primary site in Boston. The Boston site is writing to online redo logs and local archived redo logs.