added some comments.

vesoft-inc · Nov 17, 2022 · c6b9b39 · c6b9b39
1 parent 571caa9
commit c6b9b39
Showing 1 changed file with 16 additions and 6 deletions.
diff --git a/src/graph/optimizer/rule/PushFilterDownAggregateRule.cpp b/src/graph/optimizer/rule/PushFilterDownAggregateRule.cpp
@@ -89,13 +89,23 @@ StatusOr<OptRule::TransformResult> PushFilterDownAggregateRule::transform(
   newFilterNode->setCondition(newCondition);
 
   // Exchange planNode
-  newAggNode->setOutputVar(oldFilterNode->outputVar());  // ~ok
-  newFilterNode->setInputVar(oldAggNode->inputVar());    // ok
+  // before exchanging:
+  //  newAggNode's inputs and outputs are clone of the oldAggNode
+  DCHECK_EQ(newAggNode->inputVar(), oldAggNode->inputVar());
+  DCHECK_EQ(newAggNode->outputVar(), oldAggNode->outputVar());
+  //  newFilterNode's inputs and outputs are clone of the oldFilterNode
+  DCHECK_EQ(newFilterNode->inputVar(), oldFilterNode->inputVar());
+  DCHECK_EQ(newFilterNode->outputVar(), oldFilterNode->outputVar());
+
+  // newAggNode shall inherit the output of the oldFilterNode
+  newAggNode->setOutputVar(oldFilterNode->outputVar());
+  // newFilterNode shall inherit the input of the oldAggNode
+  newFilterNode->setInputVar(oldAggNode->inputVar());
   DCHECK_EQ(oldAggNode->outputVar(), oldFilterNode->inputVar());
-  // newAggNode->setInputVar(oldAggNode->outputVar());
-  newAggNode->setInputVar(oldAggNode->inputVar());
-  // newFilterNode->setOutputVar(oldAggNode->outputVar());
-  newFilterNode->setOutputVar(newAggNode->inputVar());
+  // newAggNode's input shall be newFilterNode's output
+  newAggNode->setInputVar(newFilterNode->outputVar());
+  // newFilterNode's output does not need to be changed
+  // it inheris the output from oldFilterNode as its clone
 
   // Push down filter's optGroup and embed newAggGroupNode into old filter's
   // Group