xuanyuanking opened a new pull request #25491: [SPARK-28699][Core] Disable 
using radix sort for ShuffleExchangeExec in repartition case
URL: https://github.com/apache/spark/pull/25491
 
 
   ## What changes were proposed in this pull request?
   
   Disable using radix sort in ShuffleExchangeExec when we do repartition.
   In SPARK-23207, we fixed the indeterministic result in the shuffle 
repartition case by performing a local sort before repartitioning.
   But for the newly added sort operation, we use radix sort only depends on 
the `spark.sql.sort.enableRadixSort`, it will lead to unstable sorting result 
while the expected order can't be satisfied with a radix sort on the prefix. 
For example, in this case, we need a stable order for tuple type.
   
   ## How was this patch tested?
   
   Using the integrated test below, it can return a right answer 100000000.
   ```
   import scala.sys.process._
   import org.apache.spark.TaskContext
   
   val res = spark.range(0, 10000 * 10000, 1).map{ x => (x % 1000, x)}
   // kill an executor in the stage that performs repartition(239)
   val df = res.repartition(113).cache.repartition(239).map { x =>
     if (TaskContext.get.attemptNumber == 0 && TaskContext.get.partitionId < 1 
&& TaskContext.get.stageAttemptNumber == 0) {
       throw new Exception("pkill -f -n java".!!)
     }
     x
   }
   val r2 = df.distinct.count()
   ```

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