[GitHub] [spark] cloud-fan commented on a diff in pull request #41046: [SPARK-43376][SQL] Improve reuse subquery with table cache

["cloud-fan (via GitHub)" <gi...@apache.org>]

cloud-fan commented on code in PR #41046:
URL: https://github.com/apache/spark/pull/41046#discussion_r1185323728


##########
sql/core/src/main/scala/org/apache/spark/sql/execution/adaptive/ReuseAdaptiveSubquery.scala:
##########
@@ -33,10 +33,13 @@ case class ReuseAdaptiveSubquery(
 
     plan.transformAllExpressionsWithPruning(_.containsPattern(PLAN_EXPRESSION)) {
       case sub: ExecSubqueryExpression =>
-        val newPlan = reuseMap.getOrElseUpdate(sub.plan.canonicalized, sub.plan)
-        if (newPlan.ne(sub.plan)) {
-          sub.withNewPlan(ReusedSubqueryExec(newPlan))
-        } else {
+        // `InsertAdaptiveSparkPlan` compiles subquery for each exprId, then the java object
+        // is always `eq` if two subqueries have same exprId.
+        // Check if the subquery can be reused manually instead of call `getOrElseUpdate`.
+        reuseMap.get(sub.plan.canonicalized).map { subquery =>
+          sub.withNewPlan(ReusedSubqueryExec(subquery))
+        }.getOrElse {
+          reuseMap.put(sub.plan.canonicalized, sub.plan)

Review Comment:
   do we have atomicity concerns?



-- 
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: reviews-unsubscribe@spark.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org