viirya commented on a change in pull request #32586:
URL: https://github.com/apache/spark/pull/32586#discussion_r635480379
##########
File path:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/EquivalentExpressions.scala
##########
@@ -167,7 +167,25 @@ class EquivalentExpressions {
* Returns all the equivalent sets of expressions.
*/
def getAllEquivalentExprs: Seq[Seq[Expression]] = {
- equivalenceMap.values.map(_.toSeq).toSeq
+ equivalenceMap.values.map(_.toSeq).toSeq.sortBy(_.head)(new
ExpressionOrdering)
+ }
+
+ /**
+ * Orders [Expression] by parent/child relations. The child expression is
smaller
+ * than parent expression. If there is child-parent relationships among the
subexpressions,
+ * we want the child expressions come first than parent expressions, so we
can replace
+ * child expressions in parent expressions with subexpression evaluation.
+ */
+ class ExpressionOrdering extends Ordering[Expression] {
+ override def compare(x: Expression, y: Expression): Int = {
+ if (x.semanticEquals(y)) {
+ 0
+ } else if (x.find(_.semanticEquals(y)).isDefined) {
+ 1
+ } else {
+ -1
Review comment:
Discussed offline. Thanks for the concern. I renamed the ordering class
and added more comment.
--
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:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
