Oracle topics

migrating-databases-from-non-asm-to-asm
recover standby database using incremental backup
Logminer
Auditing FGA

IP's in oracle10G

Up to Oracle 9i we use physical IP address in listener configuration. Means if requested connection gets failed then it will be diverting to another node using physical IP address of another surviving node. But during this automatically transfer, connection should need to wait up to get error message of node down or listener down using TCP/IP connection timeout. Means session should need to wait up to getting TCP/IP timeout error dictation. Once error message is received oracle RAC automatically divert this new connection request to another surviving node.


IFrom Oracle 10g, virtual IP considers to configure listener. Using virtual IP we can save our TCP/IP timeout problem because Oracle notification service maintains communication between each nodes and listeners. Once ONS found any listener down or node down, it will notify another nodes and listeners with same situation. While new connection is trying to establish connection to failure node or listener, virtual IP of failure node automatically divert to surviving node and session will be establishing in another surviving node. This process doesn't wait for TCP/IP timeout event.

IP Address Type	Purpose	Where Registered	Pingable from Clients
Virtual IP address	Address for client requests and to be used to fail over requests to other nodes	DNS (recommended), or in the /etc/hosts file for each node in the cluster, and the /etc/hostsfile for each node that is accessing the cluster database/	No, before installation; yes, after installation
Public IP address	Address for service requests	DNS, or in the /etc/hosts file for each node in the cluster.	Yes
Private IP address	Address for inter-node communication only(Cache Fusion)	DNS, or /etc/hosts file for each node in the cluster. Must be resolvable only by other nodes in the cluster, and should be on dedicated network hardware.	No