11g: Active data guard - part I

Hi Everyone!!

11g has new features for Data guard. We have Active Data guard in 11g which brings wonderful reporting environment in the business world.

Data guard can be kept in read only mode while it receives and applies the transaction from primary.

Remember: If you are keeping the database in read only mode and you are applying the redo logs then you need to have separate licensing (for Active data guard). If you are keeping the Physical standby in mount mode + receiving redo apply then you would need require active data guard license.

Another feature in 11g is that no need of intermediate RMAN back up to create data guards. I will cover the creation steps in next blog.

When you are upgrading the protection mode to maxprotection, you do not need to restart the primary database as you need to do in 10g. Only thing that you would need to do is increase step by step - from maxperformance to maxavailability and then to maxprotection.

Great benefit is there with Active data guard as all read only downstream queries can be done with ADG which will offload OLTP primary.

11gR2 has a option to flush urgent redo from primary to standby using.

SQL >alter system flush redo to 'target_db_name';

EBS with Data guard:

x. Logical standby is not supported with EBS
x. Active dataguard can not offload reporting pieces like discoverer in EBS as well as each login requires write operation in EBS

I will write articles on active data guard in next few weeks.


NO said...


long time hope all is well, do
you have note on configuring datagaurd for an EBS site ??


Suresh Lakshmanan said...

Hi NO,

Here is the note
"Business Continuity for Oracle E-Business Release 12 Using Oracle 11g Physical Standby Database [ID 1070033.1]", that might help you.

Standby for EBS vary based on your environment - how you have DNS setup - how you are resolving the aliases, RAC/no RAC.

Above note will give starting point. Thank you.