Logical migration
The workhorse. Four operating models, and the parts that need governing.
A logical migration moves schemas and objects through export, import or a migration service. It is the workhorse: it handles object-level selection, tolerates target designs that differ from the source, and pairs naturally with replication when the outage has to be short.
You have four operating models, and the choice is mostly about who owns the running of it:
- OCI Database Migration — managed, for supported source and target combinations. Least operational burden, least control.
- Zero Downtime Migration (ZDM) — more control, and correspondingly more requirements on hosts, network access and skills in your team.
- Data Pump directly — the right answer for a planned offline move. Simple, predictable, well understood.
- GoldenGate directly — for teams that need to own the replication design, or that will run both platforms alongside each other for a meaningful period.
Oracle’s managed online methods use Data Pump for the initial load and GoldenGate for synchronisation, with source-version requirements that vary by option. Those requirements move; check them against your exact release and deployment.
The parts that need governing
For an offline move, the hard question is arithmetic: does export, transfer, import, error correction, validation and business approval fit in the window? Teams size the export and import and forget the last three, which on a large platform can be the majority of the elapsed time.
For an online move, define the consistent starting point for the initial load before anything runs, and decide in advance how each object type will be handled. DDL changes during the migration, constraints, supplemental logging, credential rotation and recovery from replication lag all need named owners, because each of them will happen.
If synchronisation continues past cutover, you have made an architectural decision, not an operational one. Decide whether it supports a bounded coexistence period or a permanent integration, because that sets your requirements for conflict handling, monitoring, recovery, licensing and long-term ownership. A “temporary” replication that becomes permanent by default is a common and expensive outcome.