1Z0-997-25 Question 148
Select 2Your organization needs to migrate a 20 TB Oracle Database 19c from an on-premises data center to an OCI DB system while minimizing downtime. The database is mission-critical, with limited maintenance windows and continuous transactions. Which two approaches can best help you achieve a near-zero downtime migration?
- A
Use Oracle Data Pump for a full export/import, pausing the source database until the import completes
- B
Set up Oracle GoldenGate to replicate data in near real time prior to final switchover
- C
Create manual RMAN backups and ship them periodically, then apply incremental backups on the target
- D
Leverage Oracle Zero Downtime Migration (ZDM) to orchestrate and automate incremental data transfers
Show answer and explanation
Correct answers: B, D
Explanation
Oracle GoldenGate (Option 2) and Zero Downtime Migration (Option 4) are specifically designed to minimize or virtually eliminate downtime for database migrations to OCI. GoldenGate replicates ongoing changes in real time, and ZDM automates the incremental backup and apply process. For more details, refer to the Oracle documentation on Zero Downtime Migration and Oracle GoldenGate for step-by-step best practices.
- A. Incorrect.
Option 1: INCORRECT. Although Data Pump is a common migration tool, this approach typically requires taking the source database offline during the final export/import phase, leading to a significant downtime period for a 20 TB database. It does not meet the requirement for near-zero downtime.
- B. Correct.
Option 2: CORRECT. Oracle GoldenGate allows real-time data replication between source and target databases. You can synchronize the target with minimal performance impact on the source, then switch over quickly, thereby achieving near-zero downtime.
- C. Incorrect.
Option 3: INCORRECT. While shipping RMAN backups and applying incremental changes can reduce downtime compared to a one-time migration, it generally involves manual coordination and can still require more downtime than solutions like Oracle GoldenGate or ZDM. It may also be prone to errors if not carefully automated and tested.
- D. Correct.
Option 4: CORRECT. Oracle Zero Downtime Migration (ZDM) orchestrates data transfers using incremental backups and applies changes to the target with minimal administrator intervention. It automates many migration steps and supports a near-zero downtime approach.