Geo-mirroring provides the most complete protection against primary site failure
and, accordingly, it is a relatively expensive solution. You will need to weigh the cost
of the sophisticated disk subsystems and high-speed telecommunication lines needed
for nonintrusive geo-mirroring against the cost of losing the data in any unarchived
redo logs and the current online redo log. See Appendix B for where to find more
information about geo-mirroring.
Data Redundancy Solutions
Redundant data is another option for dealing with primary site failure. Implementing
a redundant data approach differs from using a standby database, which duplicates
the entire primary database. Data redundancy is achieved by having a copy of
your critical data in an entirely separate Oracle database with a different structure.
286 | Chapter 11: Oracle and High Availability
The data, not the database itself, is redundant. If the primary site fails, users can continue
working using the redundant data in the secondary database.
Oracle provides automated synchronous and asynchronous data-replication features
to support data redundancy.
Pages:
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625