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text-align: center; text-indent: 0pt; line-height: 28pt;">Stephen Rea

Monday, April 24, 2006  11:30 AM

Session Rules of Etiquette

No smokin'
No drinkin'
No cussin'
No tobaccer spittin'
No tomater throwin'

Data Guard - Oracle's Answer to Disaster Recovery

See how to quickly implement a Data Guard physical
standby database in a day.
Learn how to switch over to your standby database
in minutes.
Possibly offload your batch reporting workload to
your standby database.
Replace your forebodings about crashes with "Don't
worry ... be happy!"

Oracle Data Guard Concepts and Administration Release
2 (9.2)

Data Guard Flow (Oracle 9i)

Data Guard Flow (Oracle 10g)

Data Guard Protection Modes

Maximum Performance

Updates committed to primary and sent to standby without
waiting to see if they were applied to standby
Pros: Little or no effect on performance of primary
Cons: Slight chance of lost transactions (on failover)


Maximum Availability (we will implement this one)

Attempts to apply updates to standby before committed
to primary
Lowers protection to Maximum Performance temporarily
if updates can't be applied to standby
Pros: Primary continues unaffected if connection to
standby is lost or the updates are delayed
Cons: Slight performance hit on primary; lost transactions
on failover possible only if the standby has been unreachable

Data Guard Protection Modes

Maximum Protection

Assures updates are applied to standby before committed
to primary
Pros: No chance of lost transactions
Cons: Primary will freeze if connection to standby
is lost 

or the updates are delayed