cloud-fan commented on a change in pull request #27252: [SPARK-29231][SQL]
Constraints should be inferred from cast equality constraint
URL: https://github.com/apache/spark/pull/27252#discussion_r378184866
##########
File path:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/QueryPlanConstraints.scala
##########
@@ -62,11 +62,17 @@ trait ConstraintHelper {
*/
def inferAdditionalConstraints(constraints: Set[Expression]):
Set[Expression] = {
var inferredConstraints = Set.empty[Expression]
- constraints.foreach {
+ // IsNotNull should be constructed by `constructIsNotNullConstraints`.
+ val predicates = constraints.filterNot(_.isInstanceOf[IsNotNull])
+ predicates.foreach {
case eq @ EqualTo(l: Attribute, r: Attribute) =>
- val candidateConstraints = constraints - eq
+ val candidateConstraints = predicates - eq
inferredConstraints ++= replaceConstraints(candidateConstraints, l, r)
inferredConstraints ++= replaceConstraints(candidateConstraints, r, l)
+ case eq @ EqualTo(l @ Cast(_: Attribute, _, _), r: Attribute) =>
+ inferredConstraints ++= replaceConstraints(predicates - eq, r, l)
Review comment:
according to https://github.com/apache/spark/pull/27252/files#r378111623
If we have `cast(a, ...) = b` and `b = 1`, we can definitely infer `cast(a,
...) = 1`.
If we have `cast(a, ...) = b` and `a = 1`, seems we can also infer `cast(1,
...) = b`.
But I'm a bit unsure about how to do it. We may need a variant of
`replaceConstraints`, which holds an expression builder "e => cast(e, ...) =
b". It looks for attribute `a`, and replace it with `cast(1, ...) = b`.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to 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]
