The error SQL71657: Cannot create a multi-column distributed table
typically occurs in Azure Synapse Analytics when there is an issue with the distribution of columns in a distributed table, especially if you're trying to apply multiple columns for table distribution, which is not supported.
Azure Synapse Analytics supports three types of table distributions:
- Hash-distributed: You distribute data based on a hash of one column.
- Round-robin: Distributes data evenly across distributions without any specific logic.
- Replicated: The entire table is replicated on each node.
To resolve the error, ensure the following:
1. Check Distribution Method:
Ensure that you are using one of the valid distribution strategies for your table.
- If using hash-distribution, only one column can be used as the distribution key.
- If your current code uses multiple columns for distribution, you should change it to use a single column. For example:
CREATE TABLE [your_table_name] WITH (DISTRIBUTION = HASH([column_name])) AS SELECT ...
- If your current code uses multiple columns for distribution, you should change it to use a single column. For example:
2. Consider Round-robin or Replicated Distribution:
If you're unable to decide on a single distribution column or if the data does not have a natural column for distribution, you can try:
- Round-robin:
CREATE TABLE [your_table_name] WITH (DISTRIBUTION = ROUND_ROBIN) AS SELECT ...
- Replicated (use with caution, only for small dimension tables):
CREATE TABLE [your_table_name] WITH (DISTRIBUTION = REPLICATE) AS SELECT ...
- Replicated (use with caution, only for small dimension tables):
3. Fix Build Pipeline:
In your Azure DevOps pipeline, ensure that the SQL scripts you are using conform to the supported syntax for Azure Synapse Analytics. If the scripts are generated automatically, you may need to modify the template to ensure only one distribution column is used.
Let me know if you need help adjusting the code or the pipeline for this!