1Z0-1123-25 Question 4
Single answerYou are the lead architect for migrating a critical on-premises HR application, backed by a 5 TB Oracle Database 19c instance, to Oracle Cloud Infrastructure (OCI). The company requires minimal downtime during the migration to avoid disrupting payroll and HR services. Which strategy would you recommend to ensure continuous data replication and a smooth cutover with minimal risk?
- A
Export and import the entire database offline using SQL*Developer Data Pump wizards.
- B
Use Oracle Zero Downtime Migration to continuously replicate data from the on-premises database to OCI, then perform a controlled switchover.
- C
Shut down the on-premises database, copy all data files securely to OCI object storage, and reattach them to a new OCI DB System.
- D
Rebuild the HR application from scratch using microservices on OCI, then export only configuration data to the new database.
Show answer and explanation
Correct answer: B
Explanation
Oracle Zero Downtime Migration (ZDM) is a recommended solution for moving mission-critical Oracle Database workloads to OCI with minimal downtime. It provides a continuous replication process that keeps source and target databases synchronized until the final switchover. This aligns with best practices for critical, large-scale migrations where uninterrupted services are essential. Refer to the Oracle Zero Downtime Migration documentation for details on setting up replication, configuring environment prerequisites, and performing a seamless cutover.
- A. Incorrect.
Option 1 is incorrect because an offline export/import approach might be simpler, but it causes significant downtime during the export, transfer, and import phases. This does not align with the minimal downtime requirement.
- B. Correct.
Option 2 is correct because Oracle Zero Downtime Migration (ZDM) supports continuous data replication from on-premises to OCI, greatly reducing downtime by allowing near real-time synchronization. After data is synchronized, you can perform a controlled switchover, minimizing risk and business disruption.
- C. Incorrect.
Option 3 is incorrect because shutting down the on-premises database to copy data files means lengthy downtime. Although manual file transfer can work for smaller or less time-sensitive databases, it does not meet strict minimal downtime requirements.
- D. Incorrect.
Option 4 is incorrect because re-architecting the application using microservices before migrating the data would be a major overhaul. This could yield benefits long-term but introduces significant development effort and timeline risk, conflicting with the immediate need to minimize downtime.