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[SPARK-23799][SQL][FOLLOW-UP] FilterEstimation.evaluateInSet produces wrong stats for STRING #21147

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[SPARK-23799][SQL][FOLLOW-UP] FilterEstimation.evaluateInSet produces wrong stats for STRING #21147

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12 changes: 8 additions & 4 deletions .../scala/org/apache/spark/sql/catalyst/plans/logical/statsEstimation/FilterEstimation.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -392,13 +392,13 @@ case class FilterEstimation(plan: Filter) extends Logging {
val dataType = attr.dataType
var newNdv = ndv

if (ndv.toDouble == 0 || colStat.min.isEmpty || colStat.max.isEmpty) {
return Some(0.0)
}

// use [min, max] to filter the original hSet
dataType match {
case _: NumericType | BooleanType | DateType | TimestampType =>
if (ndv.toDouble == 0 || colStat.min.isEmpty || colStat.max.isEmpty) {
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@cloud-fan cloud-fan Apr 25, 2018

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I think we always have max/min for integral type? cc @wzhfy

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@wzhfy wzhfy Apr 26, 2018

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min/max could be None when the table is empty

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@mshtelma mshtelma Apr 26, 2018

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min/max can be None if the column contains only null values. This is exactly the case for my query.

return Some(0.0)
}

val statsInterval =
ValueInterval(colStat.min, colStat.max, dataType).asInstanceOf[NumericValueInterval]
val validQuerySet = hSet.filter { v =>
Expand All @@ -422,6 +422,10 @@ case class FilterEstimation(plan: Filter) extends Logging {

// We assume the whole set since there is no min/max information for String/Binary type
case StringType | BinaryType =>
if (ndv.toDouble == 0) {
return Some(0.0)
}

newNdv = ndv.min(BigInt(hSet.size))
if (update) {
val newStats = colStat.copy(distinctCount = Some(newNdv), nullCount = Some(0))
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12 changes: 12 additions & 0 deletions .../src/test/scala/org/apache/spark/sql/catalyst/statsEstimation/FilterEstimationSuite.scala
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Expand Up @@ -368,6 +368,18 @@ class FilterEstimationSuite extends StatsEstimationTestBase {
expectedRowCount = 0)
}

test("evaluateInSet with string") {
validateEstimatedStats(
Filter(InSet(attrString, Set("A0")),
StatsTestPlan(Seq(attrString), 10,
AttributeMap(Seq(attrString ->
ColumnStat(distinctCount = Some(10), min = None, max = None,
nullCount = Some(0), avgLen = Some(2), maxLen = Some(2)))))),
Seq(attrString -> ColumnStat(distinctCount = Some(1), min = None, max = None,
nullCount = Some(0), avgLen = Some(2), maxLen = Some(2))),
expectedRowCount = 1)
}

test("cint NOT IN (3, 4, 5)") {
validateEstimatedStats(
Filter(Not(InSet(attrInt, Set(3, 4, 5))), childStatsTestPlan(Seq(attrInt), 10L)),
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