ulysses-you commented on issue #26946: [SPARK-30036][SQL] Fix: REPARTITION hint does not work with order by URL: https://github.com/apache/spark/pull/26946#issuecomment-570535969 Wait, another point. First this scence also exists in `join` or `window` operator, as @viirya say, exists other Distribution. For e.g. join ``` val df = spark.range(1, 10, 2) df.join(df.repartition(10), Seq("id"), "left").explain(true) // physical plan like this = Physical Plan == *(5) Project [id#0L] +- SortMergeJoin [id#0L], [id#83L], LeftOuter :- *(2) Sort [id#0L ASC NULLS FIRST], false, 0 : +- Exchange hashpartitioning(id#0L, 200), true, [id=#378] : +- *(1) Range (1, 10, step=1, splits=40) +- *(4) Sort [id#83L ASC NULLS FIRST], false, 0 +- Exchange hashpartitioning(id#83L, 200), true, [id=#384] +- Exchange RoundRobinPartitioning(10), false, [id=#383] +- *(3) Range (1, 10, step=1, splits=40) ``` And then there is a little difference between `2 -> 10 -> 200` and `2 -> 10` because of different operator complexity. Repartition may be is a light operator compare with sort or join or else algorithm. So it's not sure `2 -> 10` is always run faster than `2 -> 10 -> 200`. The last, if end user really want result partition is 10, should use `df.sort("id").repartition(10)` instead, not the `df.repartition(10).sort("id")`. Pruning shuffle may mislead user. cc @HyukjinKwon @cloud-fan @maropu
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