OCM OCM High Availability & Disaster Recovery 2 — Questions and Answers
Question 1: What Oracle technology provides application-level, transparent failover for database connections during a planned or unplanned outage?
- Oracle Net Services Load Balancing
- Application Continuity (AC) (Correct answer)
- Transparent Application Failover (TAF)
- Fast Application Notification (FAN)
Correct answer: Application Continuity (AC)
Application Continuity replays in-flight transactions on a new database session after a recoverable failure, making the outage transparent to the application without code changes.
Question 2: In Oracle Data Guard, which protection mode guarantees zero data loss by requiring the standby to acknowledge redo receipt before the primary commits?
- Maximum Performance
- Maximum Availability
- Maximum Protection (Correct answer)
- Synchronous Replication
Correct answer: Maximum Protection
Maximum Protection mode requires at least one standby to confirm redo receipt before each primary transaction commits; if no standby is reachable, the primary shuts down.
Question 3: Which Oracle utility is used to clone a database or create a standby database directly from the primary without prior backups?
- Data Pump impdp
- RMAN DUPLICATE … FROM ACTIVE DATABASE (Correct answer)
- SQL*Loader
- GoldenGate Initial Load
Correct answer: RMAN DUPLICATE … FROM ACTIVE DATABASE
RMAN DUPLICATE … FROM ACTIVE DATABASE streams datafiles directly from the primary (or auxiliary) instance over an Oracle Net connection to build a clone or standby without needing RMAN backups.
Question 4: What is the role of the Oracle Notification Service (ONS) in a RAC or Data Guard environment?
- Publishing Fast Application Notification (FAN) events to middleware and connection pools about service state changes (Correct answer)
- Encrypting redo data sent to standby databases
- Managing redo log archival across all RAC instances
- Distributing SQL execution plans to all cluster nodes
Correct answer: Publishing Fast Application Notification (FAN) events to middleware and connection pools about service state changes
ONS propagates FAN events (instance up/down, service relocate) from the cluster to JDBC/OCI connection pools and middleware, enabling rapid connection failover and load balancing.
Question 5: In Oracle Data Guard Broker, what is the purpose of the DGMGRL command SWITCHOVER TO?
- Performs a planned role transition with no data loss between primary and standby (Correct answer)
- Forces an emergency failover when the primary is unavailable
- Converts a physical standby to a logical standby
- Resynchronizes a lag standby after network interruption
Correct answer: Performs a planned role transition with no data loss between primary and standby
SWITCHOVER TO performs an orderly, zero-data-loss role reversal where the current primary becomes a standby and the target standby becomes the new primary.
Question 6: Which Oracle feature automatically extends a tablespace by adding a new datafile or expanding an existing one when space runs out?
- Locally Managed Tablespace
- Automatic Extensible Datafiles (AUTOEXTEND ON) (Correct answer)
- Bigfile Tablespace
- Automatic Segment Management
Correct answer: Automatic Extensible Datafiles (AUTOEXTEND ON)
AUTOEXTEND ON configures a datafile to automatically grow by a specified increment (up to MAXSIZE) when the tablespace runs out of free space, preventing allocation failures.
OCM OCM High Availability & Disaster Recovery 2
What Oracle technology provides application-level, transparent failover for database connections during a planned or unplanned outage?