OCM High Availability & Disaster Recovery Flashcards

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

Answer: Physical Standby in Maximum Availability mode

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

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

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

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.

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

Answer: Cluster Synchronization Services (CSS)

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

In Oracle RAC, what does Cache Fusion do?

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

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.

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

Answer: Maximum acceptable duration of downtime after a failure event

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

Which RMAN command validates backup pieces and image copies without actually restoring them?

Answer: VALIDATE BACKUPSET

VALIDATE BACKUPSET reads backup pieces and verifies block checksums to confirm that the backup is readable and internally consistent without performing an actual restore.