Can you please explain ,is there any different fetching functionality in OGG while using FAILOVER_MODE = (TYPE = SELECT)(METHOD = BASIC)) and FAILOVER_MODE = (TYPE = SESSION)(METHOD = BASIC)) in Oracle RAC configuration ?
For Example, Normally if there is an node failure in RAC while transaction happening, Oracle request / response process will take care of that failuer node commited transactions like roll backward method and helped to write the data in to data files, like that how gg will capture the roll back process data if node failed ?Please clarify.
Thanks in Advance.
If the redo logs are in ASM, OGG will continue to use the ASM connection to pull the details out of the redo log. If the redo logs are on raw devices, they should be shared to all systems, so even if the node goes down, the online log will be available for reading. The only event where it would not be available is if the storage server crashed that held the online redo logs or the ASM files... in that case, there isn't much OGG can do because the system is down.
Once it comes back up, OGG can be restarted and it will pick up right where it left off and continue processing all the transactions from all nodes.
Another option, is to use Downstream Integrated Extract.