1Z0-1123-25 Question 6
Single answerYou are migrating an 8 TB on-premises Oracle Database to Oracle Cloud Infrastructure (OCI). The database must remain available with minimal disruption to business-critical applications. Which approach best ensures near-zero downtime for this migration?
- A
Use Oracle Data Pump in a single downtime window to export and then import all data.
- B
Use Zero Downtime Migration (ZDM) with Oracle Data Guard to synchronize data between on-premises and OCI.
- C
Use the Oracle Data Transfer Appliance to physically ship database files to OCI, then switch connections at cutover.
- D
Perform a manual backup and restore to OCI, followed by post-migration data validation and re-indexing.
Show answer and explanation
Correct answer: B
Explanation
To achieve minimal downtime for large-scale database migrations, Zero Downtime Migration (ZDM) leverages technologies like Oracle Data Guard or Oracle GoldenGate for continuous replication. This ensures data consistency and keeps the source and target databases in sync, reducing the downtime to the final cutover stage. Refer to Oracle's official documentation on Zero Downtime Migration for detailed implementation best practices.
- A. Incorrect.
Option 1 is incorrect because using Oracle Data Pump alone for an 8 TB database can result in a long outage. While Data Pump is a reliable tool for data movement, the size of the database and the need for near-zero downtime make it less suitable if you cannot accommodate an extended maintenance window.
- B. Correct.
Option 2 is correct. Zero Downtime Migration (ZDM) with Oracle Data Guard can continuously replicate changes from the on-premises database to OCI, minimizing downtime to the cutover phase. This approach allows near real-time synchronization, helping ensure availability and data consistency.
- C. Incorrect.
Option 3 is incorrect because while the Oracle Data Transfer Appliance expedites large data moves, you still need to handle incremental changes separately. The process works well for bulk data shipping but does not inherently guarantee near-zero downtime unless coupled with additional replication mechanisms.
- D. Incorrect.
Option 4 is incorrect because a purely manual backup and restore process typically demands substantial downtime. After the restore, you would need to apply outstanding transactions and verify data integrity, which does not align with near-zero downtime requirements.