diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala index 34bd243d58de9efc149956f2c27bed243616c92e..b19344f04383f7dfabe17ccbf244af24a97fd8bd 100644 --- a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala +++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala @@ -40,7 +40,7 @@ private[sql] object FrequentItems extends Logging { if (baseMap.size < size) { baseMap += key -> count } else { - val minCount = baseMap.values.min + val minCount = if (baseMap.values.isEmpty) 0 else baseMap.values.min val remainder = count - minCount if (remainder >= 0) { baseMap += key -> count // something will get kicked out, so we can add this @@ -83,7 +83,7 @@ private[sql] object FrequentItems extends Logging { df: DataFrame, cols: Seq[String], support: Double): DataFrame = { - require(support >= 1e-4, s"support ($support) must be greater than 1e-4.") + require(support >= 1e-4 && support <= 1.0, s"Support must be in [1e-4, 1], but got $support.") val numCols = cols.length // number of max items to keep counts for val sizeOfMap = (1 / support).toInt diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameStatSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameStatSuite.scala index ab7733b239f283fba7465c03f2d52df000051880..73026c749db450afb61f00f4fc85dbde797edec4 100644 --- a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameStatSuite.scala +++ b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameStatSuite.scala @@ -235,6 +235,17 @@ class DataFrameStatSuite extends QueryTest with SharedSQLContext { assert(items.length === 1) } + test("SPARK-15709: Prevent `UnsupportedOperationException: empty.min` in `freqItems`") { + val ds = spark.createDataset(Seq(1, 2, 2, 3, 3, 3)) + + intercept[IllegalArgumentException] { + ds.stat.freqItems(Seq("value"), 0) + } + intercept[IllegalArgumentException] { + ds.stat.freqItems(Seq("value"), 2) + } + } + test("sampleBy") { val df = spark.range(0, 100).select((col("id") % 3).as("key")) val sampled = df.stat.sampleBy("key", Map(0 -> 0.1, 1 -> 0.2), 0L)