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Schema Validation runs automatically after each pipeline sync to verify that the number of rows at the destination matches the source. It gives you confidence that data moved correctly — nothing was dropped, duplicated, or silently lost.

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How it works

After a sync completes, Zwiron queries both the source and the destination and compares row counts for each table that was synced:
If the counts don’t match, the table is flagged with a validation failure and you can see the discrepancy in the job detail.

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What gets validated

  • Full Refresh — full table row count at source vs. destination after replace
  • Incremental — rows added in this run vs. rows inserted/upserted at destination
  • CDC — cumulative row count across source and destination

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Viewing results

Validation results are visible on the job detail page for each run:
  1. Go to Jobs → select a job
  2. Scroll to the table list
  3. Each table shows its validation status:
    • ✅ Match — row counts agree
    • ❌ Mismatch — source and destination counts differ (count shown for both)
    • ⚠️ Error — validation query failed (e.g. destination unreachable)

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When counts don’t match

A mismatch doesn’t always mean data loss — some causes are expected: If none of these apply and counts differ significantly, investigate the run logs for errors.

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Validation and data integrity

Validation is a sanity check — it catches gross errors (a table that failed to write, a transform that filtered too aggressively, a destination that rejected rows). It is not a full data-quality audit. For deeper validation (column-level checksums, value distribution checks), use a tool like Great Expectations or dbt tests on your destination data.
Last modified on July 13, 2026