The client has a database (instance + physical db).
instance is of SGA and Processes and
physical db is of Ctlfiles, init.ora, logfiles and datafiles
The requirement is:
he wants us to create a instance pointing to the
same db. reason. if any process fails in instance A,
then the instance B should pick up as it is pointing
to the same db files. then start exploring why A has failed.
Is this possible. And how??
Any suggestions are greatly appreciated
The only way to do this (assuming you want both instances running simultaneously) is with Oracle is to use the Oracle Parallel Server (OPS) option. However, this imposes some potentially expensive hardware requirements (multiple boxes, raw devices, high speed buses) that might outweigh the need for concurrent instances.
For ORACLE fail safe is concerned You need a NT cluster.
You have to ask the NT system administartor about this.Oracle has to installed on both nodes.Where oracle files are there those disks should be common to both the nodes.
But with oracle fail safe if the oracle fails in one node (A).It will start up and running in the Node B.So for databases which has 24*7 requirements they can go for this.I have worked on this for a year and it worked with any problem.Even oracle 7.3 can be used on this.You do not need to about ORACLE parallel server concepts and all.
Inc ase you want to go for high availablilty of your Database instance , You can go for Veritas or Sun HA (High Availablity ) clustering . It is a better and a more relaible solution than Creating a standby database.
oracle failsafe is only a software which will run on top of Windows NT cluster. With out oracle failsafe also windows NT cluster can move the database instance from one node to another, but when it moves it will do a shutdown abort and then move it. If oracle failsafe software is installed in the cluster and if you move the database form one node to another thru the failsafe , It will do a normal shutdown and move it to the other node. Basically this will ensure the database is in good condition when it is moving from one node to another.
If you want to know more about windows NT clustering mail me to firstname.lastname@example.org.