Moving records is often treated as the short task between an old system and a new one. In practice, it is where missing definitions, duplicate identities and years of inconsistent entry become visible. The migration plan needs to explain what will happen to those differences.
Inventory the source first
Identify the datasets, owners, date coverage and relationships. Record which system is authoritative for each field. Keep an unchanged source copy through the agreed migration process so that transformation decisions can be investigated.
Map meanings as well as columns
Two fields with similar names may describe different things. Agree the destination meaning, permitted values and handling of blanks. A transformation rule should be understandable to the person responsible for the information, not only the person writing the import.
Make exceptions visible
Decide how duplicates, missing references and invalid values will be handled. A rejected record needs a reason and a review route. Quietly dropping a difficult row may make a job appear successful while leaving the service incomplete.
Reconcile at useful levels
Compare source and destination counts, identities and relationships. Where totals or balances matter, agree how they will be checked. Keep a record of accepted transformations and unresolved exceptions so reviewers can see what the migration established.
Rehearse the changeover
A representative rehearsal can expose ordering problems, slow steps and dependencies on other systems. Agree the cutover sequence, the point at which writes stop or change, the responsible people and the conditions for proceeding or returning to the earlier arrangement.
Restore something before relying on recovery
PostgreSQL documents several backup approaches with different assumptions. Select the approach around the deployment and operating needs, then verify the relevant restore procedure. A backup file alone is not evidence that the required service can be recovered.
The handover should let a responsible person answer three questions: what moved, what changed and what still needs a decision. That record makes future corrections and support more manageable.
Take it into the brief
A practical checklist.
- Source inventory and field ownership agreed
- Mappings and transformation rules reviewed
- Rejected and duplicate records given a review route
- Counts, identities and relevant totals reconciled
- Cutover and recovery responsibilities established
- Representative restore and acceptance checks recorded
Further reading.
Primary references checked 1 November 2026. The design approach above is the studio’s own explanatory guidance.
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