Migration Approaches

There are several approaches that can be used to migrate a very large Oracle database to Oracle Cloud Infrastructure (OCI). Here are a few common ones:

  • Full Export and Import: The most common and straightforward approach is to use Oracle’s export and import utilities (EXPORT and IMPORT) to create a full backup of the on-premises database and then restore it to the OCI database. This approach is the simplest to implement, but it can take a long time to complete if the database is very large.

  • Data Pump: Another approach is to use Oracle’s Data Pump utility, which can export and import data more efficiently than the traditional export/import utilities. Data Pump supports parallel processing, which can greatly speed up the migration process. Data pump provides more options for data movement than the traditional export import.

  • GoldenGate: Oracle GoldenGate is a real-time data integration and replication software that can be used to replicate data from an on-premises database to an OCI database. GoldenGate can replicate data in near real-time and can handle high volumes of data and high-availability requirements.

  • Transportable Tablespaces: Another approach is to use Transportable Tablespaces (TTS) feature, in this case you move only the required subset of tablespaces instead of entire database, this way you can quickly move large amount of data, this method can be used in scenario where you need to move specific set of data instead of entire database.

  • Cloud Data Guard: Finally, you can leverage Oracle’s Cloud Data Guard, which allows you to create a physical or logical standby of an on-premises database in OCI. This approach allows you to keep the standby in sync with the primary database, so you can switch over to the standby in the event of a disaster.

Conclusion

  • Practice, practice, practice
  • Start on small database
  • Prove it works on production-size database
  • Automate
    • To ensure consistency and avoid human error
  • Save all logs and output
    • Data Pump, RMAN
  • Clean-up procedure
    • In case of failure and rollback
    • To repeat tests
    • Offline source database afterwards

Oracle Migration MOS References

  • Migrate Databases Using the Migration Tools (OCI-C To OCI) (Doc ID 2549638.1)
  • MAA Practices for Cloud Migration Using ZDM (Doc ID 2562063.1)
  • MOS 2674405.1 Using Transportable Tablespaces to Migrate Oracle E-Business Suite Release 12.2 Using Oracle Database 19c Enterprise Edition On a Multitenant Environment)
  • Master Note for Transportable Tablespaces (TTS) – Common Questions and Issues (Doc ID 1166564.1)
  • Transportable Tablespace (TTS) Restrictions and Limitations: Details, Reference, and Version Where Applicable  (Doc ID 1454872.1)
  • V4 PERL Scripts to reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup (Doc ID 2471245.1)
  • Known Issues for Cross Platform Transportable Tablespaces XTTS (Doc ID 2311677.1)
  • Cross Platform Database Migration using ZDLRA (Doc ID 2460552.1)
  • 11G – Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup (Doc ID 1389592.1)
  • 12C – Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup (Doc ID 2005729.1)