Too many columns in the line.

Question

HdfsBridge::recordReaderFillBuffer - Unexpected error encountered filling record reader buffer: HadoopExecutionException: Too many columns in the line.

This error is being displayed when I am trying to view top 10 results from a table in azure synapse analytics, the column type and format is consistent with the external table.

Answer 1

Hello @kshitijjain-0490

You may have already checked the mappings list, but if you haven't, I would recommend starting by verifying they are correct since that is the usual cause https://learn.microsoft.com/en-us/azure/synapse-analytics/sql-data-warehouse/design-elt-data-loading#define-the-tables:

If everything looks good there, it will help narrow things down to know if this only happens on an external table or if the query will work fine if you can access it from a view.

If neither of those give any new info, there are a couple things that will help me try to reproduce the problem. First is whether you are running this on a dedicated or serverless pool. The second big one would be the mappings you are using. If there is any proprietary info in the column names please change them to something generic, but it would help a lot to know what the table structure is.