The majority of the migration can take place during normal AE operation, parallel to your usual workload activities. Online part #1 addresses the large set of historical data in the AE DB that no longer changes. Old data is copied to the new UTF-8 AE DB. The Workflow provides three modes that copy data from the source to the destination DB:
- Initial - copies the main part of the data.
- Refresh - copies the delta data since the initial or last refresh step. It can be repeated multiple times to keep the data copied in Final as little as possible.
- Final - copies the last portion of data and creates the SQL statements for the offline step.
Offline part #2 happens during the AE’s downtime. It focuses on recently changed data, which could not be copied in the online step. As of now, you cannot use your old database anymore. The AE is shut down, and the AE DB data no longer changes. The SQL statements generated in the Online Step are executed on the destination DB. The SQL statements generated after the final mode are applied to the destination DB while the AE is offline/shut down. The remaining data is copied from the source to the destination DB with the help of a DB link.
