12.1.0.2 install on windows 2012 R2

Question

Hi friends,
We are planning on migrating  databases from 11.2 to 12c on Win 2012 server.  Currently there are about 6 11g instances(different customer's and development databases) on one server. We will need to migrate all of them in the near future. I was reading up on the multitenant option in 12c, seems to be a great option for us hosting multiple databases on one server. But all these databases have different character sets(WE8MSWIN1252, AL32UTF8, WE8ISO8859P1) depending on the client needs.. From what I understand, the character set will be set in the container CDB and all the PDB databases will be using the same character set? Is it not possible to use different character sets and different init parameters for the respective PDB's? Also, since they are customer databases and development databases , the database size and memory needs will widely vary among the different databases.. Can this be a problem? ANy thoughts are really appreciated.... THank you so much

Answer 1

We are planning on migrating  databases from 11.2 to 12c on Win 2012 server.  Currently there are about 6 11g instances(different customer's and development databases) on one server. We will need to migrate all of them in the near future. I was reading up on the multitenant option in 12c, seems to be a great option for us hosting multiple databases on one server. But all these databases have different character sets(WE8MSWIN1252, AL32UTF8, WE8ISO8859P1) depending on the client needs.
A database can only have ONE character set. Makes no difference if you are using 12c, 11g, 10g, 9i, 8i.
. From what I understand, the character set will be set in the container CDB and all the PDB databases will be using the same character set?
Close - a multitenant DB is ONE database - so can only have ONE character set. All components of that ONE DB use that same character set. Each PDB is a component of that ONE DB.
Is it not possible to use different character sets and different init parameters for the respective PDB's?
There is only ONE database - so it only has ONE character set, one set of REDO logs, one set of memory management.
Chapters 17 and 18 of the Concepts doc discuss the ONE database and how each of those components works in that context
http://docs.oracle.com/database/121/CNCPT/cdbovrvw.htm
Also, since they are customer databases and development databases , the database size and memory needs will widely vary among the different databases.
Just so what I said earlier was not misunderstood - there is ONLY ONE DB. So there is  only ONE memory management component. When you size memory you size it to meet the requirements of that ONE DB which, by necessity, means the requirements of ANY AND ALL PDBs that you plan to have open simultaneously.
If you want to manage REDO and memory independently for each customer then you need a separate dabase for each customer.
As Srini noted that separate database can be a standard (non-multitenant) 12c DB.
Oracle 12c multitenant is a NEW architecture. Until your DBA staff has expertise in that architecture you should NOT consider using it for a production environment. It is vital that you conduct the full range of dev/test/performance test/qa test of the development lifecycle.
Even seemingly simple, mundane things like starting up the DB, connecting to the CDB or PDBs, creating users, making grants and more are either TOTALLY NEW or radically different.
No matter what the level of expertise a DBA has they will NOT be successful doing even those basic things without having first RTFM.
The above isn't meant to alarm you or discourage you from using 12c. It is merely to relate the facts as I see them. The preponderance of the forum questions have been about things as simple as 'why can I not connect to the hr schema'.
In particular see my length reply in this thread:
12c database - empty container vs PDB