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Posted to github@datafusion.apache.org by "andygrove (via GitHub)" <gi...@apache.org> on 2026/04/30 19:14:52 UTC

[PR] feat: improve shuffle size estimation [experimental!] [datafusion-comet]

andygrove opened a new pull request, #4164:
URL: https://github.com/apache/datafusion-comet/pull/4164

   ## Which issue does this PR close?
   
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   ## Rationale for this change
   
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   Change the default sizeInBytesMultiplier from 1.0 to 2.0 so that out-of-the-box Comet better preserves Spark's join strategy decisions.
   
   Add a new config spark.comet.shuffle.sizeInBytesMultiplier.dynamic that, when enabled, computes the multiplier from the shuffle output schema by comparing per-field Arrow columnar widths against UnsafeRow fixed-width costs. This gives a more accurate estimate for schemas where the ratio varies significantly (e.g. narrow bool/byte columns vs wide long columns).
   
   
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Re: [PR] feat: improve shuffle size estimation [experimental!] [datafusion-comet]

Posted by "andygrove (via GitHub)" <gi...@apache.org>.
andygrove closed pull request #4164: feat: improve shuffle size estimation [experimental!]
URL: https://github.com/apache/datafusion-comet/pull/4164


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