Explanation
Autonomous TransactionProcessing comes with predefined CPU/IO shares assigned to different consumer groups. You can modify these predefined CPU/IO shares if your workload requires different CPU/IO resource allocations.
By default, the CPU/IO shares assigned to the consumer groups TPURGENT, TP, HIGH, MEDIUM, and LOW are 12, 8, 4, 2, and 1, respectively. The shares determine how much CPU/IO resources a consumer group can use with respect to the other consumer groups. With the default settings the consumer group TPURGENT will be able to use 12 times more CPU/IO resources compared to LOW, when needed. The consumer group TP will be able to use 4 times more CPU/IO resources compared to MEDIUM, when needed.

Explanation
Pre-authenticated requests provide a way to let users access a bucket or an object without having their own credentials, as long as the request creator has permissions to access those objects. For example, you can create a request that lets an operations support user upload backups to a bucket without owning API keys. Or,you can create a request that lets a business partner update shared data in a bucket without owning API keys.
When you create a pre-authenticated request, a unique URL is generated. Anyone you provide this URL to can access the Object Storage resourcesidentified in the preauthenticated request, using standard HTTP tools like curl and wget.
Understand the following scope and constraints regarding pre-authenticated requests:
Users can't list bucket contents.
You can create an unlimited number of pre-authenticated requests.
There is no time limit to the expiration date that you can set.
You can't edit a pre-authenticated request. If you want to change user access options in response to changing requirements, you must create a new preauthenticated request.
The target and actions for a pre-authenticated request are based on the creator's permissions. The request is not, however, bound to the creator's account login credentials. If the creator's login credentials change, a pre-authenticated request is not affected.
You cannot delete a bucket that has a pre-authenticated request associated with that bucket or with an object in that bucket.
Understand the following scope and constraints regarding public access:
Changing the type of access is bi-directional.You can change a bucket's access from public to private or from private to public.
Changing the type of access doesn't affect existing pre-authenticated requests. Existing pre-authenticated requests still work.

Explanation
When creating a compartment, you must provide a name for it (maximum 100 characters, including letters, numbers, periods, hyphens, and underscores) that is unique within its parent compartment. You must also provide a description, which is a non-unique, changeable description for the compartment, from 1through 400 characters.
After creating a compartment, you need to write at least one policy for it, otherwise no one can access it (except administrators or users who have permissions set at the tenancy level). When creating a compartment inside anothercompartment, the compartment inherits access permissions from compartments higher up its hierarchy.
When you create an access policy, you need to specify which compartment to attach it to. This controls who can later modify or delete the policy. Dependingon how you've designed your compartment hierarchy, you might attach it to the tenancy, a parent, or to the specific compartment itself.