What causes SYNAPSE_SQL_0008?

Parquet file contains complex types (ARRAY, MAP, STRUCT) not supported in serverless SQL. Delta Lake file uses features not yet supported in Synapse Serverless. Decimal precision exceeds the maximum supported by the serverless endpoint

How do I fix SYNAPSE_SQL_0008?

Step 1: Identify the unsupported column from the error message.. Step 2: Cast the column to a supported type in the OPENROWSET or external table definition.. Step 3: For complex types, use Spark (Synapse Spark pool or Databricks) to flatten the schema first.. Step 4: Check the Synapse documentation for the current list of supported Parquet types in serverless.

Medium severityconfiguration

Power BI Refresh Error:
SYNAPSE_SQL_0008

What does this error mean?

Synapse Serverless SQL does not support a data type used in the external file or schema definition.

Common causes

1Parquet file contains complex types (ARRAY, MAP, STRUCT) not supported in serverless SQL
2Delta Lake file uses features not yet supported in Synapse Serverless
3Decimal precision exceeds the maximum supported by the serverless endpoint

How to fix it

1Step 1: Identify the unsupported column from the error message.
2Step 2: Cast the column to a supported type in the OPENROWSET or external table definition.
3Step 3: For complex types, use Spark (Synapse Spark pool or Databricks) to flatten the schema first.
4Step 4: Check the Synapse documentation for the current list of supported Parquet types in serverless.

Frequently asked questions

How do I monitor for Unsupported Data Type in Serverless SQL in my pipelines?

Connect Azure Data Factory to MetricSign — failed pipeline runs trigger incident alerts with the root cause, so your team is notified before users notice report failures.

Official documentation: https://learn.microsoft.com/en-us/azure/synapse-analytics/sql/troubleshoot-synapse-studio