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  1. Spark
  2. SPARK-37451

Performance improvement regressed String to Decimal cast

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Details

    • Bug
    • Status: Resolved
    • Blocker
    • Resolution: Fixed
    • 3.1.0, 3.1.1, 3.1.2, 3.2.0, 3.1.3, 3.2.1
    • 3.1.3, 3.2.1
    • Spark Core

    Description

      A performance improvement to how Spark casts Strings to Decimal in this PR title, has introduced a regression

      scala> :paste 
      // Entering paste mode (ctrl-D to finish)
      
      import org.apache.spark.sql.types._
      import org.apache.spark.sql.Row
      spark.conf.set("spark.sql.legacy.allowNegativeScaleOfDecimal", true)
      spark.conf.set("spark.rapids.sql.castStringToDecimal.enabled", true)
      spark.conf.set("spark.rapids.sql.castDecimalToString.enabled", true)
      val data = Seq(Row("7.836725755512218E38"))
      val schema=StructType(Array(StructField("a", StringType, false)))
      val df =spark.createDataFrame(spark.sparkContext.parallelize(data), schema)
      df.select(col("a").cast(DecimalType(37,-17))).show
      
      
      // Exiting paste mode, now interpreting.
      
      +--------------------+
      |                   a|
      +--------------------+
      |7.836725755512218...|
      +--------------------+
      
      scala> spark.version
      res2: String = 3.0.1
      
      
      scala> :paste
      // Entering paste mode (ctrl-D to finish)
      
      import org.apache.spark.sql.types._
      import org.apache.spark.sql.Row
      spark.conf.set("spark.sql.legacy.allowNegativeScaleOfDecimal", true)
      spark.conf.set("spark.rapids.sql.castStringToDecimal.enabled", true)
      spark.conf.set("spark.rapids.sql.castDecimalToString.enabled", true)
      val data = Seq(Row("7.836725755512218E38"))
      val schema=StructType(Array(StructField("a", StringType, false)))
      val df =spark.createDataFrame(spark.sparkContext.parallelize(data), schema)
      df.select(col("a").cast(DecimalType(37,-17))).show
      
      // Exiting paste mode, now interpreting.
      
      +----+
      |   a|
      +----+
      |null|
      +----+
      
      import org.apache.spark.sql.types._
      import org.apache.spark.sql.Row
      data: Seq[org.apache.spark.sql.Row] = List([7.836725755512218E38])
      schema: org.apache.spark.sql.types.StructType = StructType(StructField(a,StringType,false))
      df: org.apache.spark.sql.DataFrame = [a: string]
      
      scala> spark.version
      res1: String = 3.1.1
      

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            yumwang Yuming Wang
            razajafri Raza Jafri
            Robert Joseph Evans Robert Joseph Evans
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            Dates

              Created:
              Updated:
              Resolved: