Less Than Troubleshooting¶

Common problems when creating and running a Less Than check, their causes, and how to resolve them.

Validation Fails When Creating the Check¶

Clicking Validate returns an error instead of a success message.

Cause: The rule could not run against the selected data. The most common reasons are an invalid Filter Clause expression, a connection problem with the source, or a container that failed to load.

Resolution:

1. Review the error message: it explains what needs attention.
2. Check the Filter Clause for typos: it must be a valid SQL WHERE expression for the selected container.
3. If the message says the container is marked as Unloadable, the container was skipped after repeated operation failures. Follow the steps in Unloadable Container Error.

A Value Equal to the Threshold Is Flagged¶

Rows whose value equals the threshold appear as anomalies.

Cause: Inclusive is off, so the comparison is < and the threshold itself fails.

Resolution: Turn Inclusive on to accept the threshold value, or lower the threshold when the intent was a different boundary.

Values That Miss by a Rounding Difference Are Flagged¶

The check reports rows that are off by a fraction.

Cause: With no Numeric comparator, the comparison is exact.

Resolution: Set an absolute or relative margin on the Numeric comparator so deviations smaller than the margin pass. Keep the margin small enough that real regressions still fail.

Rows With NULL Values Are Not Flagged¶

Rows with an empty field pass the check.

Cause: This is by design: NULL values pass. Less Than only constrains present values.

Resolution: Pair the check with a Not Null check on the same field to also require presence.

The Field Is Unavailable in the Field Picker¶

The column you want to check appears under Field, but it cannot be selected.

Cause: The picker only enables Integral and Fractional fields. An array column, a numeric field nested inside an array of structs (stored as an array), and a number stored as text remain visible but unavailable.

Resolution: Expose the column with a numeric type upstream, or project it through a Computed Field, then select that field.

An Edited Check Keeps Behaving the Old Way¶

You changed the configuration but the anomaly list did not change.

Cause: Edits take effect on the next Scan. Saving the check does not re-evaluate the data, and anomalies raised under the previous configuration are not modified.

Resolution: Run a Scan on the container (or wait for the scheduled one). Old anomalies stay open until you triage them or a Full scan with Auto Resolve clears them. See What Happens to Existing Anomalies.

No Anomalies Although the Data Looks Wrong¶

A Scan ran, the data clearly breaks the rule, but nothing was reported.

Cause: One of these configurations is excluding the violations:

• The check is in Draft status: Draft checks are not evaluated by Scans.
• The Filter Clause excludes those rows before the evaluation runs.
• Coverage is below 100% and the failing fraction stayed within the tolerance, so the check passed.

Resolution: Confirm the check is Active and test the filter expression against the offending rows. Then review the coverage setting; see Coverage and Tolerance.

Expected One Anomaly per Row, Got a Single Rolled-Up One¶

Many rows failed, but the scan reported one Shape Anomaly instead of per-row Record Anomalies.

Cause: When the number of failing rows exceeds the scan's rollup threshold, the per-row findings are grouped into one rolled-up Shape Anomaly.

Resolution: This is expected behavior; the rolled-up anomaly carries sampled source records. To change the threshold, see Maximum Record Anomalies per Check.