xiedeyantu commented on code in PR #4745:
URL: https://github.com/apache/calcite/pull/4745#discussion_r2692381943
##########
core/src/main/java/org/apache/calcite/plan/RelTraitSet.java:
##########
@@ -389,7 +389,14 @@ public RelTraitSet getDefaultSansConvention() {
*/
@SuppressWarnings("unchecked")
public <T extends RelCollation> @Nullable T getCollation() {
- return (@Nullable T) getTrait(RelCollationTraitDef.INSTANCE);
+ RelTrait trait = getTrait(RelCollationTraitDef.INSTANCE);
+ if (trait instanceof RelCompositeTrait) {
+ // If the trait is a composite trait, we return the first one as a
+ // representative trait. If RelCompositeTrait contain [[a, b], [a]].
+ // Selects [a,b] as it implies [a]; preserves the strongest ordering.
+ return (T) ((RelCompositeTrait) trait).trait(0);
Review Comment:
I think I need to revisit the RelCompositeTrait handling to see if I need to
add a new interface, as the current getCollation() seems insufficient.
--
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.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
