Explanation
- In, Oracle Autonomous Database, Customers are not given OS logons or SYSDBA privileges to prevent phishing attacking.
- If a bare metal DB system requiresmore compute node processing power, you can scale up (increase) the number of enabled CPU cores in the system without impacting the availability of that system.
You cannot change the number of CPU cores for a virtual machine DB system in the same way as metal DB system. Instead, you must change the shape to one with a different number of OCPUs Changing the shape does not impact the amount of storage available to the DB system. However, the new shape can have different memory and network bandwidth characteristics, and you might need to reapply any customizations to these aspects after the change.

Explanation
Access to Your On-Premises Network
There are two ways toconnect your on-premises network to Oracle Cloud Infrastructure:
VPN Connect: Offers multiple IPSec tunnels between your existing network's edge and your VCN,by way of a DRG that you create and attach to your VCN.
Oracle Cloud Infrastructure FastConnect: Offers a private connection between your existing network's edge and Oracle Cloud Infrastructure. Traffic does not traverse the internet. Both private peering and public peering are supported. That means your on-premises hosts can access private IPv4 addresses in your VCN as well as regional public IPv4 addresses in Oracle Cloud Infrastructure (for example, Object Storage or public load balancers in your VCN).
You can use one or both types of the preceding connections. If you use both, you can use them simultaneously, or in a redundant configuration. These connections come to your VCN by way of a single DRG that you create and attach to your VCN. Without that DRG attachment and a route rule for the DRG, traffic does not flow between your VCN and on-premises network. At any time, you can detach the DRG from your VCN but maintain all the remaining components that form the rest of the connection. You could then reattach the DRG again, or attach it to another VCN.

Explanation
References:
The terraform plan command is used to create an execution plan. Terraform performs a refresh, unless explicitly disabled, and then determines what actions are necessary to achieve the desired state specified in theconfiguration files.
This command is a convenient way to check whether the execution plan for a set of changes matches your expectations without making any changes to real resources or to the state. For example, terraform plan might be run before committing a change to version control, to create confidence that it will behave as expected.

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.