1Z0-1123-25 Question 137
Single answerYou are migrating a mission-critical 30 TB Oracle Database 19c from your on-premises data center to an OCI Exadata Database Service. Your leadership has allocated only a few hours for final cutover and insists on minimal downtime. The on-premises database must remain operational until the switchover. Which migration strategy is best suited for this scenario?
- A
Use Oracle Data Pump to export and import the entire database in a single downtime window
- B
Perform an RMAN backup and restore directly from on-premises to the OCI database
- C
Implement Oracle GoldenGate to replicate changes and perform a switchover at cutover time
- D
Manually copy datafiles to OCI and use custom scripts to synchronize changes
Show answer and explanation
Correct answer: C
Explanation
For mission-critical databases with strict downtime constraints, Oracle GoldenGate offers a proven solution for near real-time replication. It continuously synchronizes data from your on-premises environment to the OCI database, enabling organizations to maintain normal operations until the final switchover. Oracle documentation recommends using GoldenGate or Oracle Zero Downtime Migration (which leverages GoldenGate under the hood) for scenarios requiring minimal downtime and uninterrupted service during database migrations.
- A. Incorrect.
Option 1 (Oracle Data Pump) is incorrect because, while Data Pump is viable for smaller databases or less stringent downtime requirements, exporting and importing 30 TB in a single downtime window is typically impractical and would cause a significant production outage.
- B. Incorrect.
Option 2 (RMAN backup and restore) can work for migrating databases, but it typically requires a longer downtime window for large data volumes. It also doesn't keep the source and target databases synchronized in real time, making it less suitable for minimal-downtime requirements.
- C. Correct.
Option 3 (Oracle GoldenGate) is correct because it offers near real-time replication of an on-premises database to the target OCI Exadata Database Service. This approach minimizes downtime by allowing continuous data synchronization until a swift switchover occurs. It also keeps the on-premises database operational throughout the migration.
- D. Incorrect.
Option 4 (Manually copy datafiles and use custom scripts) is incorrect as it would demand complex custom solutions, introduce higher risk of human error, and not provide nearly the same level of automation, data integrity checks, or near-zero downtime capabilities as Oracle GoldenGate.