Few doubts about 11g R2 Policy Based/Scan

I have gone through several documents including Oracle's help to understand oracle's new feature Policy Based management/Scan, I also explored few RACSIG webinar by Markus which were helpful but still not able to understand the concept fully. I will be thankful if someone can help me to understand the concept please.

Document says - benefit of creating server pool (policy based ) is to manage workload automatically. I do not understand how this is going to manage workload automatically. I have understood based on importance and min/max setting, servers are going to allocate/ deallocate to pools accordingly.

For example - one server pool is : high_priority pool with 2 min servers. with high priority, it is serving 2 instance of payroll database
another server pool : low_priority pool with 2 min servers with low prioirty, it is serving 2 instance of HR database

In case, any server from high_priority got evicted, it should take one server from low_priority. (That's what expression i have so far after going through documentations. Please correcti if I am wrong ).

1st question : doest that mean it is going to stop one instances of HR running on low_priority pool and going to allocate that server to high_priority
and accordingly payroll instance is going to up.

2nd question : Can we still achive TAF functionality while using Server pools. I read either i can have Uniform service which is running on all instances
( i assume this means preferred ) .. or service can run on any single server (singletone)
3rd question : With SCAN functionality, where we set remote_listener=SCAN_LISTENER, and clients first connects to SCAN and then got re-routed to local listener.
what is the benefit of having VIP for each node. SCAN listener knows which instance is up, which one is least loaded can directly forward connections
local listener. ( we can start using public ip for listener )

my doubt is : in 10g, we only used vip to get fast notification or avoid tcp timeout .. and then we got re-route to some other listener/ node to connect
now SCAN can do the same functionality ..

Thanks in Advance, I appreciate your time.

Regards,
Lyxx Received on Fri May 13 2011 - 02:15:46 CDT