JkSelf opened a new pull request, #11643:
URL: https://github.com/apache/incubator-gluten/pull/11643

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   ## What changes are proposed in this pull request?
   
   When offloading Hash Join to Velox, Gluten currently cannot fully leverage 
the performance benefits of the Hash Join Key Rewriting feature. In fact, 
enabling this feature can lead to performance degradation.
   
   During our optimization of BHJ—aimed at building the hash table only once 
per executor—we discovered that Dynamic Filter Push-down DFP is enabled when 
Key Rewriting is enabled. This occurs because the rewriting process introduces 
CAST(int AS long) expressions to both the Build and Probe sides within the 
Project operator. Since Velox only supports filter push-down on columns without 
complex expressions, these added casts block the optimization, resulting in a 
performance degradation.
   
   To address this, we have disabled the Key Rewriting feature specifically 
within the HashJoin#canRewriteAsLongType method.
   
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   ## How was this patch tested?
   
   Existing unit tests
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   ## Was this patch authored or co-authored using generative AI tooling?
   
   No
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