Time Machine data access is a feature of Nutanix Database Service (NDB) that allows you to access a point-in-time snapshot of a database without restoring it. To use this feature, you need to create a Data Access Management (DAM) policy that defines the access mode, the source database, the destination cluster, and the storage container mapping. The storage container mapping is needed when the source database and the NDB Server containers are different, because NDB needs to know where to store the metadata and the clone of the source database. If the source database and the NDB Server containers are the same, then NDB will use the same container for both the metadata and the clone.Reference:

Nutanix Certified Professional - Database Automation (NCP-DB), Section 5 - Protect NDB-managed Databases Using Time Machine

Database (NCP-DB) Exam Blueprint Guide - Nutanix, Page 9, Objective 5.6

Nutanix Database Management & Automation (NDMA) course, Module 4, Lesson 4.2 - Data Access Management

To roll back an Oracle patch on a database server VM using NDB, the patch must have been applied using NDB in the first place. This is because NDB maintains a patch inventory and history for each database server VM and database that it manages. NDB uses this information to determine which patches can be rolled back and how to revert the changes made by the patch. If the patch was applied outside of NDB, NDB would not have the patch information and would not be able to roll back the patch. Therefore, the patch must have been applied using NDB for the rollback action to be successful. The other options are not required for the rollback action. The database does not need to be shut down or in read-only mode, as NDB can perform the rollback operation online. The patch does not need to be applied on Grid home only, as NDB can roll back patches applied on both Grid home and Database home.Reference:

Nutanix Certified Professional - Database Automation (NCP-DB) v6.5, Section 4 - Operate and Maintain an NDB Environment, Objective 4.4: Determine the correct method to apply Linux OS patches

Nutanix Database Management & Automation (NDMA) Course, Module 5: Nutanix Database Service (NDB) Patching, Lesson 5.1: Patching Overview, Topic: Patching Concepts

[Nutanix Database Service (NDB) User Guide], Chapter 7: Patching, Section: Rolling Back a Patch

According to the Nutanix Database Automation (NCP-DB) learning documents, when dealing with an Availability Group (AG) database, the database should be registered as an Availability database1. This is because the AG database is hosted on replicas with different named instances, and registering it as an Availability database allows for Copy Data Management operations to be performed across all instances.This is particularly important when services such as the Analytics service running on SQLAGN3\DW require real-time data1.

Data Access Management (DAM) policies are a feature of NDB Multi-Cluster that allows you to control the access and availability of time machine data across different Nutanix clusters. You can use DAM policies to specify which clusters can access the time machine data of a source database, and which clusters can replicate the time machine data for backup or disaster recovery purposes. DAM policies help you to optimize the storage and network resources, as well as ensure the security and compliance of your database workloads. The purpose of DAM policies is not to register multiple Nutanix clusters in NDB, as this is done by using the Add Cluster option in the NDB settings page. The purpose of DAM policies is also not to perform snapshot operations on a single Nutanix cluster, as this is done by using the Time Machine feature in the NDB dashboard. The purpose of DAM policies is also not to remove data accessibility of a time machine across all registered Nutanix clusters in NDB, as this is done by using the Delete option in the Time Machine page.Reference:

Nutanix Database Management & Automation Training Course, Module 6: Managing NDB Multi-Cluster, Lesson 2: Data Access Management Policies, Slide 3: Data Access Management Policies

Nutanix Certified Professional - Database Automation (NCP-DB) 5 Exam, Section 6: Administer an NDB Environment, Objective 6.5: Apply procedural concepts to create Data Access Management (DAM) policies

Nutanix Era leverages the Nutanix time-efficient snapshots to create the clones1.These database clones are highly space-efficient, consuming near-zero bytes by having only the further writes constituting to its size1. Therefore, an administrator would find the total space being used by all Era clones for a specific database under the Cloning widget on the Databases > Clones database summary page. The other options do not specifically provide information about the total space used by all Era clones for a specific database. Therefore, the correct answer is A. Under the Cloning widget on the Databases > Clones database summary page.