ORACLE INSTANCE

Knowledge Base

1.I want to know that in How maney instances can be created in one Physical Server?
2.How maney Databases can be created in one instance?

Thanks

Hi;
I know that the ORACLE_SID contains 4 Letters
Probably with 8i/9i there are even more.
With Combination of 4 Letters you can theoretically create 27^4 Instances and even more when you use digits 0-9

One Instance can only connect to one physical Database.

Orca

1. unlimited provided you have enough resources.
2. 1

Quote:

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Originally posted by mamdba
2.How maney Databases can be created in one instance?

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Instance means the collection of all structures of the database server running together. Structures means all kinds of memories, resources, processes, etc.

One database can be associated with several instances, i.e., you can mount and open the same databases on physically different nodes. This was possible since 1989 and is known before 9i as OPS and in 9i as RAC.

Back to your question: you do not create databases in an intstance. Rather the database is part of the instance.

Thank you very much