SQL Developer

The Oracle materials seem to favor RAC databases being created as Policy-Managed.  In the real world however I noticed many of my colleagues creating them as Admin-Managed.

Remember that your colleagues shop is different from your environment. Have you ever asked any of your colleagues why they decide to implement ADMIN Managed over Policy Managed?

I'll suggest you start here: Oracle Database 12c: Why and How You Should Be Using Policy-Managed Oracle RAC Databases.

It should help to dispel you think and give you insight about why it's best to use Policy Managed over Admin Managed.

In addition:

Deploying Policy-Managed Databases

When you deploy a policy-managed database you must first determine the services and their required sizing, taking into account that services cannot span server pools. If you are going to collocate this database with other databases, then you should factor in its CPU requirements relative to the other hosted databases, and also factor in the value of its CPU_COUNT attribute for instance caging, so that you can size the database both vertically and horizontally in one or more server pools.
If you are going to collocate the server pools for this database with other server pools, then consider configuring the server pools to adjust the server pool sizes on a calendar or event basis to optimize meeting demand and business requirements. Once you have determined the sizes of the server pools, and configured the appropriate values for the MIN_SIZE and MAX_SIZE server pool attributes, you can then determine the relative importance of each server pool. Managing a policy-managed database requires less configuration and reconfiguration steps than an administrator-managed one with respect to creation, sizing, patching, and load balancing. Also, because any server in the server pools within the cluster can run any of the databases, you do not have to create and maintain database instance-to-node-name mappings. You can perform maintenance tasks such as patching by relocating servers into the Free pool or by adjusting the server pool minimum and maximum sizes, thereby retaining required availability.

Admin Manager database

For administrator-managed databases, you must ensure that the database software is deployed on the nodes on which you plan to run the respective database instances. You must also ensure that these nodes have access to the storage in which you want to store the database files. Oracle recommends that you select Oracle ASM during database installation to simplify storage management. Oracle ASM automatically manages the storage of all database files within disk groups. If you plan to use Oracle Database Standard Edition to create an Oracle RAC database, then you must use Oracle ASM to store all of the database files.
For policy-managed databases, you must ensure that the database software is deployed on all nodes on which database instances can potentially run, given your active server pool setup. You must also ensure that these nodes have access to the storage in which you want to store the database files. Oracle recommends using Oracle ASM, as previously described for administrator-managed databases.

You can get the detail in the official documentation: https://docs.oracle.com/database/121/RACAD/admcon.htm#RACAD8895

In addition, I'll also suggest you read over this Oracle before deciding whether to use Policy or Managed http://www.nocoug.org/download/2013-05/NoCOUG_201305_Why_and_How_Using_Policy_Managed_Databases.pdf

Sincere thanks for the detailed response.

As all my posts, prior to posting I search Oracle docs, Google and these forums.  When I am still missing puzzle pieces or have not found how to make the theory practical...I post here.  I am thinking of adding this to my signature line.  :-)

What do YOU  do in the real world production environments you work in concerning creating RAC database for this topic.  Do you create them as Policy or Admin managed and why?

What are the key attributes that you found that made you choose one over the other?

Thanks.

I create mine as admin-managed. I've never had a reason to use policy-managed, at least not yet.

Cheers,
Brian

Hi Mary

How many nodes you have in your cluster?If you are on a basic 2 node cluster,then it doesn't matter Admin or policy managed.

But say if you have 8 node RAC ,it would help in the effective use of resources  if you create a policy-managed database with associated  server pools.

Also you can configure new features like QoS

Regards

Robin

When I am still missing puzzle pieces or have not found how to make the theory practical...I post here.  I am thinking of adding this to my signature line.  :-)

To think use it you need go into  Oracle Database QoS Management.

Oracle Database QoS Management is an automated, policy-based product that monitors the workload requests for an entire system. Oracle Database QoS Management manages the resources that are shared across applications and adjusts the system configuration to keep the applications running at the performance levels needed by your business. Oracle Database QoS Management responds gracefully to changes in system configuration and demand, thus avoiding additional oscillations in the performance levels of your applications.

https://docs.oracle.com/database/121/APQOS/apqos_intro.htm#APQOS109

Here a pratical example:

https://www.youtube.com/watch?v=H8I69nyiwdw

LOL!!!

Policy managed for DBAs trained by Oracle ! The Imaginary World.

I would also add...Policy managed are for those who have unlimited checkbooks or don't care about the money the company spends. If I have an extra node in the cluster "just sitting there" waiting to be added to support my RAC database at a moments noticed, that extra node needs to be licensed for Oracle EE and RAC! If I licensed that node, it ain't going to be sitting there idle. I'm gonna be using it!

Cheers,

Brian