Workload scope
Validation and reconciliation covers the evidence needed to prove migrated workloads preserve business meaning before cutover.
Shared migration method
Define the contract before conversion: the assets and business measures that must match, their allowable variance, the comparison window, and the owner who can accept an exception. Validate in layers—readiness and execution first, then counts and profiles, KPI aggregates, targeted row-level differences, and finally rerun, late-arrival, backfill, and rollback behaviour.
Treat a successful compilation or one reconciled snapshot as evidence of neither operational correctness nor cutover readiness. The validation record should capture the source and target query versions, parameter sets, result evidence, threshold, decision, owner, and follow-up action.
Cutover evidence
- Reconcile representative historical and current windows, including null-heavy, duplicate, boundary-date, and late-arriving cohorts.
- Test idempotency by rerunning an already-applied window, then simulate restart and backfill paths.
- Agree pass/fail thresholds before results are inspected; use an exception register for known, accepted differences.
- Gate production cutover on an explicit canary, rollback trigger, and post-cutover sentinel plan.
When to use a pair-specific guide
Use a retained pair-specific page when the source platform changes the reconciliation method—for example Delta MERGE semantics, Snowflake restart behaviour, Oracle CDC, or a target-specific cost and pruning constraint. The shared guide is the canonical method; pair pages add only named platform risks that alter the validation plan.
Review points
- Inventory coverage and reconciliation scope
- Row counts, aggregates, checksums, and profile comparison
- Golden reports and accepted variance thresholds
- Exception triage, sign-off, and rollback criteria
Acceptance criteria
A validation & reconciliation page is complete when the migration team can identify source assets, understand conversion assumptions, review unsupported or ambiguous constructs, run validation checks, and decide whether the workload is ready for cutover.
For each related path, confirm that the child page explains what changes, how conversion works, which patterns are supported, what can drift, and which evidence is required before production traffic moves to the target platform.