This is an automated email from the ASF dual-hosted git repository.
andygrove pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/datafusion-comet.git
The following commit(s) were added to refs/heads/main by this push:
new 577a793e3a fix: clean up CometCast support-level reporting (#4501)
(#4595)
577a793e3a is described below
commit 577a793e3a2d43146371e6fd6a5c9e1a1189d551
Author: Andy Grove <[email protected]>
AuthorDate: Thu Jun 4 17:27:12 2026 -0600
fix: clean up CometCast support-level reporting (#4501) (#4595)
---
.../org/apache/comet/expressions/CometCast.scala | 23 +++++++++++++---------
.../scala/org/apache/comet/CometCastSuite.scala | 7 ++-----
2 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/spark/src/main/scala/org/apache/comet/expressions/CometCast.scala
b/spark/src/main/scala/org/apache/comet/expressions/CometCast.scala
index 68c4d1fb7e..bcc9ee0692 100644
--- a/spark/src/main/scala/org/apache/comet/expressions/CometCast.scala
+++ b/spark/src/main/scala/org/apache/comet/expressions/CometCast.scala
@@ -32,6 +32,10 @@ import org.apache.comet.shims.CometExprShim
object CometCast extends CometExpressionSerde[Cast] with CometExprShim {
+ // Shared with CometCastSuite so the asserted reason cannot drift from
production.
+ private[comet] val negativeScaleDecimalToStringReason: String =
+ "Negative-scale decimal requires
spark.sql.legacy.allowNegativeScaleOfDecimal=true"
+
def supportedTypes: Seq[DataType] =
Seq(
DataTypes.BooleanType,
@@ -48,17 +52,17 @@ object CometCast extends CometExpressionSerde[Cast] with
CometExprShim {
DataTypes.TimestampType,
DataTypes.TimestampNTZType)
- override def getIncompatibleReasons(): Seq[String] = Seq(
- "Some cast operations between specific type pairs may produce different
results than Spark." +
- " Refer to the compatibility guide for the full matrix of supported cast
operations.")
-
- override def getUnsupportedReasons(): Seq[String] = Seq(
- "Not all cast type combinations are supported. Unsupported casts fall back
to Spark.")
+ // Note: `getIncompatibleReasons` / `getUnsupportedReasons` are
intentionally not
+ // overridden here. The per-pair `isSupported` matrix is the canonical
source of cast
+ // reasons: `cast.md` is generated directly from it (see
`GenerateDocs.writeCastMatrixForMode`)
+ // and EXPLAIN surfaces the per-pair reason via `getSupportLevel`. A single
static sentence
+ // would only duplicate the matrix and risk drifting from it.
override def getSupportLevel(cast: Cast): SupportLevel = {
if (cast.child.isInstanceOf[Literal]) {
- // casting from literal is compatible because we delegate to Spark
- // further data type checks will be performed by CometLiteral
+ // A cast whose child is a literal is folded by Spark at planning time
via `cast.eval()`
+ // (see `convert`), so the cast never executes natively and the result
matches Spark by
+ // definition. `CometLiteral` then validates the resulting literal's
data type.
Compatible()
} else {
isSupported(cast.child.dataType, cast.dataType, cast.timeZoneId,
evalMode(cast))
@@ -254,7 +258,8 @@ object CometCast extends CometExpressionSerde[Cast] with
CometExprShim {
val allowNegativeScale = SQLConf.get
.getConfString("spark.sql.legacy.allowNegativeScaleOfDecimal",
"false")
.toBoolean
- if (allowNegativeScale) Compatible() else Incompatible()
+ if (allowNegativeScale) Compatible()
+ else Incompatible(Some(negativeScaleDecimalToStringReason))
case _: DecimalType =>
// Compatible across all eval modes: LEGACY uses
cast_decimal128_to_utf8 which
// replicates Java BigDecimal.toString() (scientific notation when
adj_exp < -6);
diff --git a/spark/src/test/scala/org/apache/comet/CometCastSuite.scala
b/spark/src/test/scala/org/apache/comet/CometCastSuite.scala
index 6c93481fe0..c527858507 100644
--- a/spark/src/test/scala/org/apache/comet/CometCastSuite.scala
+++ b/spark/src/test/scala/org/apache/comet/CometCastSuite.scala
@@ -787,11 +787,8 @@ class CometCastSuite extends CometTestBase with
AdaptiveSparkPlanHelper {
}
withSQLConf("spark.sql.legacy.allowNegativeScaleOfDecimal" -> "false") {
assert(
- CometCast.isSupported(
- negScaleType,
- DataTypes.StringType,
- None,
- CometEvalMode.LEGACY) == Incompatible())
+ CometCast.isSupported(negScaleType, DataTypes.StringType, None,
CometEvalMode.LEGACY) ==
+ Incompatible(Some(CometCast.negativeScaleDecimalToStringReason)))
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
