feat: improve shuffle size estimation [experimental!]#4164
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andygrove wants to merge 1 commit intoapache:mainfrom
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feat: improve shuffle size estimation [experimental!]#4164andygrove wants to merge 1 commit intoapache:mainfrom
andygrove wants to merge 1 commit intoapache:mainfrom
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…plier 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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Which issue does this PR close?
Closes #.
Rationale for this change
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).
What changes are included in this PR?
How are these changes tested?