alamb commented on PR #14644: URL: https://github.com/apache/datafusion/pull/14644#issuecomment-2665613858
> > This PR can't solve > > select * from t consumes 2GB memory to fully materialize the output, in the best case select * from t order by c1 consumes around 2GB memory, given sorting is an O(1) space operation. The current situation is it consumes 4GB+ (more than 2 times). > > I think this is by design. The physical operators should not reserve memory for the batches it produces. It is the parent operator's duty to reserve memory for the batches fetched from children operators if it needs to hold the batches in memory for a long time. This is a great observation and I think holds true in practice However I don't think it is reflected in the documention here https://docs.rs/datafusion/latest/datafusion/execution/memory_pool/trait.MemoryPool.html Would someone be willing to update those docs? -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
