Data Diff Anomaly Reporting

How the Data Diff check reports differences: the anomaly message it produces, what the counts mean, how the differing rows are rendered side by side, and why per-row anomalies do not apply.

Anomaly Messages

When the Data Diff check fires, it produces a single Shape Anomaly describing the dataset-level violation, with the per-row detail attached as Comparison Source Records. The check does not produce Record Anomalies; the diff is a property of the target as a whole.

There are N records that differ between `<target_container>` (T records) and `<reference_container>` (R records) in `<reference_datastore_name>` and S have been sampled for enrichment

The target container is named first, the reference second. Data Diff builds this message itself rather than through the shared anomaly templates, so it carries no [filter: <expression>] suffix even when a filter is set.

What the Numbers Mean

• N: the number of differing rows. When Diff Change Types restricts the reported statuses, only rows with a selected status are counted.
• T: total row count in the target container after its filter is applied.
• R: total row count in the reference container after ref_filter is applied.
• S: how many of the differing rows were sampled into the Comparison Source Records. It equals N until the scan's enrichment source-record limit caps it.

The message has no singular form: a single differing row still reads There are 1 records that differ.

Source Records Behavior

When Row Identifiers are configured, the per-row detail is rendered in the Comparison Source Records view rather than the standard Source Records list. The columns, in order:

1. Row Status: one of added, removed, changed.
2. Row Identifier: the identifier value (or tuple) that pairs the target and reference rows.
3. For each listed field: a parent column spanning two sub-columns, Left (target) and Right (reference).

Only the right-side cell of the differing field is highlighted; the left side and the row identifier are not. When a row is added, the reference has no row to read and the right-side cell shows the literal text missing; when a row is removed, the target has no row to read and the left-side cell shows missing.

See Comparison Source Records for the full UI reference.

Custom Anomaly Description

Custom Anomaly Description does not apply to this rule. The option replaces the message on Record Anomalies, and Data Diff emits a Shape Anomaly only. The per-row detail lives in the Comparison Source Records view, not in the message.

See Also