ERPstuff - Oracle EBS Community

Hi,

I am little confused between Dataguard and RAC.. both are used for High Availability... then what is the difference? Do we choose only one at a time? or we can have both at same time?

Please explain

ta
Arvin

Hi Arvin

The main difference is disaster recovery time. The RAC is expensive Active Active solution (both nodes available at a time) which provide the immediate fail over solution. While Dataguard is Active Passive (one node is available at a time).

Another difference is DataGurad sites can be physically remote (even on another continent so delay must be there). While RAC nodes are placed within the same premises (so no downtime at all).

Some time we use combination of both, like creating a Stand by database for one of the RAC node. In this scenario if whole RAC goes down (because of being on the same premises) then remote Standby database will become available.

Hope that will help you to understand the differences.

Amir

Hi,

RAC addresses system failures. RAC gives automatic recovery from failure (node failure, instance crash) of the system which doesn?t affect data. RAC also increased scalability for an application by load balancing.

Data Guard is a backup solution of the primary database. It is configured to recover from the event of failure of the primary database. Data Guard database can be RAC?d

Rizwan Cheema

Hi Amir,

I dont know whether the information given by you is helpful for anyone or not, but I am confident to say that now I have come to know about the difference b/w DG and RAC.


MUNA.

[quote]Hi Arvin

The main difference is disaster recovery time. The RAC is expensive Active Active solution (both nodes available at a time) which provide the immediate fail over solution. While Dataguard is Active Passive (one node is available at a time).

Another difference is DataGurad sites can be physically remote (even on another continent so delay must be there). While RAC nodes are placed within the same premises (so no downtime at all).

Some time we use combination of both, like creating a Stand by database for one of the RAC node. In this scenario if whole RAC goes down (because of being on the same premises) then remote Standby database will become available.

Hope that will help you to understand the differences.

Amir

<i><div align="right">Originally posted by amirtai

Thanks for appreciation. That's our main objective to elaborate the concepts in easy going way instead of using difficult definitions from patent documentation.

Amir