zhuqi-lucas commented on PR #16398: URL: https://github.com/apache/datafusion/pull/16398#issuecomment-2988228245
> > Got it, so we add Cooperative to some operators such as sort_perserve_merging when partition > 1 > > No, that hasn't changed (or at least it shouldn't have). When SPM has more than 1 input, it acts as an exchange and drives the inputs itself. This is advertised using `EvaluationType::Eager`. It makes use of tokio mpsc channels which are (and were) already consuming the tokio task budget. Because of this implementation aspect SPM advertises itself as `SchedulingType::Cooperative`. The optimizer should not be adding `CooperativeExec` here. I'll double check to be sure. The query I was investigating specifically doesn't use SPM though. > > Note that each exchange is also a task boundary, so task budget consumption does not leak from below the exchange to above it or vice versa. Since all the inputs to SPM are all driven as distinct tasks, there also shouldn't be any competition amongst the inputs. > > (I'm stating things as fact above, but this only reflects my current understanding. Working on double checking everything.) Ok, i see MPSC already for SPM, we only add the `EvaluationType::Eager` type to it, we don't add another yield/budget. It should not affect performance. -- 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
