OCM OCM High Availability & Disaster Recovery

Question 1

In Oracle Data Guard, which role does the primary database's standby perform when it actively processes redo in real time?

Accepted Answer

Physical Standby in Maximum Availability mode

Answer

A Physical Standby in Maximum Availability mode applies redo data in real time using Redo Apply (MRP), maintaining synchronization with near-zero lag.

Question 2

What is the primary purpose of a Far Sync instance in Oracle Data Guard?

Accepted Answer

Receive redo from the primary synchronously and forward it asynchronously to terminal standbys

Answer

A Far Sync instance sits close to the primary, receives redo synchronously (zero data loss), and ships it asynchronously to distant standbys, combining zero-RPO with low latency.

Question 3

Which Oracle RAC component manages cluster membership and arbitrates split-brain scenarios?

Accepted Answer

Cluster Synchronization Services (CSS)

Answer

CSS (Cluster Synchronization Services) maintains node membership, detects failures through missed heartbeats, and initiates node eviction to prevent split-brain data corruption.

Question 4

In Oracle RAC, what does Cache Fusion do?

Accepted Answer

Transfers data blocks between node buffer caches over the private interconnect to avoid disk reads

Answer

Cache Fusion uses the high-speed private cluster interconnect to ship modified data blocks directly between instance buffer caches, eliminating the need for intermediate disk writes.

Question 5

What is the Recovery Time Objective (RTO) primarily concerned with?

Accepted Answer

Maximum acceptable duration of downtime after a failure event

Answer

RTO defines the maximum tolerable time from a failure event until business services are restored, directly driving high availability architecture decisions.

OCM - Oracle Certified Master Practice Test

OCM - Oracle Certified Master Practice Test

OCM OCM High Availability & Disaster Recovery