maropu commented on a change in pull request #23726: [SPARK-26812][SQL] Report
correct nullability for complex datatypes in Union
URL: https://github.com/apache/spark/pull/23726#discussion_r253499819
##########
File path:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala
##########
@@ -230,9 +231,19 @@ case class Union(children: Seq[LogicalPlan]) extends
LogicalPlan {
}
// updating nullability to make all the children consistent
- override def output: Seq[Attribute] =
- children.map(_.output).transpose.map(attrs =>
- attrs.head.withNullability(attrs.exists(_.nullable)))
+ override def output: Seq[Attribute] = {
+ children.map(_.output).transpose.map { attrs =>
+ val firstAttr = attrs.head
+ val outAttr = try {
+ firstAttr.withDataType(attrs.map(_.dataType).reduce(StructType.merge))
+ } catch {
+ // If the data types are not compatible (eg. Decimals with different
precision/scale)
+ // return the first type
Review comment:
All type compatibly checks should be in `resolved`?
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
