tustvold commented on PR #2677: URL: https://github.com/apache/arrow-datafusion/pull/2677#issuecomment-1170120699
> is the the eventual plan to interleave IO and CPU decoding Yes, once we properly support reading and writing the column index structures https://github.com/apache/arrow-rs/issues/1705 we will have sufficient information to interleave IO at the page-level. Currently ParquetRecordBatchStream does not have information on where the pages are actually located, which means it cannot interleave IO at a granularity lower than the column chunk. That being said we could potentially use a heuristic and only fetch the first 1MB or something, I'll have an experiment :thinking: Full disclosure the column in question is somewhat degenerate, it is 106MB over 100x 1MB pages across two row groups. Another obvious way to improve the performance would be to reduce the size of the row groups. -- 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]
