tustvold opened a new issue, #4658: URL: https://github.com/apache/arrow-datafusion/issues/4658
**Describe the bug** ExternalSorter currently spills data using the Arrow IPC format, unfortunately the IPC file format does not support replacing a dictionary with the same ID. Consequently if `ExternalSorter` spills two batches with dictionary encoded columns, it will error with ``` Dictionary replacement detected when writing IPC file format. Arrow IPC files only support a single dictionary for a given field across all batches ``` **To Reproduce** **Expected behavior** Various options present themselves: * Number the dictionary IDs consistently across DataFusion (a monumental task) * Write batches to separate files * Spill to the row format instead of Arrow IPC Of these I think the last is the most compelling, I plan to work on this in the coming month **Additional context** It is possible Ballista also runs into this issue -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
