OCM High Availability & Disaster Recovery Flashcards

What is the purpose of the RMAN RECOVER … UNTIL TIME command?

Answer: Performs incomplete (point-in-time) recovery to restore the database to a specific timestamp

RECOVER … UNTIL TIME performs incomplete recovery, rolling the database forward through archived and online redo logs to the exact timestamp specified, then stopping for RESETLOGS.

In Oracle RAC, what is a 'service' and why is it important for high availability?

Answer: A named workload unit that can be started, stopped, and relocated across instances to maintain availability

A RAC service is a named logical unit of work that runs on one or more instances; if an instance fails, the service automatically relocates to a surviving instance, providing continuous availability.

Which Oracle technology provides block-level storage replication independent of the Oracle software stack?

Answer: Oracle ASM Mirroring

Oracle ASM (Automatic Storage Management) built-in mirroring replicates data blocks across failure groups at the storage layer, providing redundancy without relying on the database redo mechanism.

What does the FLASHBACK DATABASE command rely on to reconstruct earlier database states?

Answer: Flashback Logs stored in the Fast Recovery Area

Flashback Database uses flashback logs written to the Fast Recovery Area that capture before-images of changed blocks, allowing the database to be rewound to an earlier SCN or timestamp.

In an Oracle Data Guard configuration, what is a 'snapshot standby'?

Answer: A physical standby temporarily converted to a fully updatable database for testing, then re-synchronized

A snapshot standby is a physical standby that has been converted to allow DML/DDL for testing; when converted back, accumulated changes are discarded and redo is re-applied to resync with the primary.

Which metric does Oracle's Recovery Point Objective (RPO) measure in a disaster recovery plan?

Answer: Maximum acceptable amount of data loss measured in time

RPO defines the maximum duration of data loss a business can tolerate; it determines how frequently data must be replicated or backed up to meet business continuity requirements.