gianm opened a new pull request, #16775: URL: https://github.com/apache/druid/pull/16775
Two performance enhancements: 1) Direct merging of input frames to output channels, without any temporary files, if all input frames fit in memory. 2) When doing multi-level merging (now called "external mode"), improve parallelism by boosting up the number of mergers in the penultimate level. To support direct merging, FrameChannelMerger is enhanced such that the output partition min/max values are used to filter input frames. This is necessary because all direct mergers read all input frames, but only rows corresponding to a single output partition. -- 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: commits-unsubscr...@druid.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org