Oracle Instance

Dear all,

Kindly,

What is the Advantages/disadvantages of having different oracle Instances or  have oracle instances with the same name on different servers and all is from  Single database (master) to multi cluster.

If the master database stop do that impact the instance or cluster one? if the server where master database is stop do that mean all instance will be stop or no impact in the instance database?

Do any changes in the master database in any tables structure will be migrate to other?

Are data entered will be store in the master and instances?

Can we make any changes in the instance in the table structure or this only done in the master?


Regarads