Oracle 1z0-915-1 Exam With Confidence Using Practice Dumps

For a read replica on a DB system,it must have at least 64 GB of memory(Answer D). This requirement ensures that the read replica has sufficient resources to handle read operations and maintain performance consistency with the primary DB system.

References:

OCI MySQL Read Replicas Documentation

When changing the storage size of a DB system,you cannot decrease the DB system's storage size(Answer B). This restriction ensures data integrity and prevents potential data loss that could occur if the storage size were reduced.

You can only increase the storage size of the DB system.

The storage increase is done online without shutting down the DB system, allowing for uninterrupted operations.

References:

OCI MySQL DB System Scaling Documentation

In a high-availability DB system, the placement of primary and secondary instances should ensure redundancy across different availability domains (ADs) and fault domains (FDs) to minimize downtime and data loss. The placement mentioned in option D is not valid because itplaces the primary and secondary instances in the same availability domain and fault domain, which does not provide high availability.