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Medium severitydata source

Power BI Refresh Error:
ParquetMissedDecimalPrecisionScale

What does this error mean?

A DECIMAL column in the Parquet file is missing required precision and scale metadata. ADF requires explicit precision and scale to interpret decimal columns.

Common causes

  • 1The Parquet writer that created the file omitted precision and scale annotations on decimal columns
  • 2The Parquet file was generated by a tool that writes raw binary decimals without annotation

How to fix it

  1. 1Specify the expected precision and scale for the decimal column in the ADF Parquet dataset schema definition.
  2. 2If you control the Parquet writer, update it to include precision and scale annotations on decimal columns.
  3. 3Use a data flow transformation to cast the raw decimal value to the correct precision and scale after reading.

Frequently asked questions

Does this error affect all pipeline runs or just the current one?

Depends on the root cause. A persistent misconfiguration fails every run; a transient issue may resolve on retry. Check the run history.

Can this error appear in Azure Data Factory and Microsoft Fabric pipelines?

Yes — the same connector errors appear in both ADF and Fabric Data Factory pipelines.

How do I see the full error detail for an ADF pipeline failure?

In ADF Monitor, click the failed run, then the failed activity. The detail pane shows the error code, message, and sub-error codes.

Will downstream Power BI datasets be affected when an ADF pipeline fails?

Yes — a dataset refreshing after the pipeline will use stale data or fail if the target table was cleared. The Power BI refresh may succeed while serving wrong data.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/connector-troubleshoot-parquet

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