[GitHub] [spark] wangyum commented on a change in pull request #34051: [SPARK-36809][SQL] Remove broadcast for InSubqueryExec used in DPP

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wangyum commented on a change in pull request #34051:
URL: https://github.com/apache/spark/pull/34051#discussion_r716439637



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File path: sql/core/src/main/scala/org/apache/spark/sql/execution/dynamicpruning/PartitionPruning.scala
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@@ -172,8 +172,7 @@ object PartitionPruning extends Rule[LogicalPlan] with PredicateHelper with Join
       // We can't reuse the broadcast because the join type doesn't support broadcast,
       // and doing DPP means running an extra query that may have significant overhead.
       // We need to make sure the pruning side is very big so that DPP is still worthy.
-      canBroadcastBySize(otherPlan, conf) &&

Review comment:
       I'm thinking could we remove it to make `PartitionPruning` more clear. This is because this approach has 2 disadvantages:
   1. Disable `spark.sql.optimizer.dynamicPartitionPruning.reuseBroadcastOnly`.
   2. The filtering side will be evaluated 2 times. For example: https://github.com/apache/spark/pull/29726#issuecomment-780266596
   
   
   Instead, we can use bloom filter join pruning. It has 2 advantages:
   1. Do not need consider broadcast.
   2. Reuse shuffle exchange to avoid the filtering side evaluate 2 times. For example: https://github.com/apache/spark/pull/33914#issuecomment-913120675




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