[CALCITE-7274] Code Review

Author: NobiGo

core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java

@@ -3103,12 +3103,25 @@ protected RelNode createJoin(
           p.id, requiredCols, joinType);
     }
 
-    final RelNode node =
+    RelNode node =
         relBuilder.push(leftRel)
             .push(rightRel)
             .join(joinType, joinCond)
             .build();
 
+    final CorrelationUse correlationUseInJoin = getCorrelationUse(bb, node);
+    if (correlationUseInJoin != null) {
+      assert correlationUseInJoin.r instanceof Join;
+      Join joinRelTemp = (Join) correlationUseInJoin.r;
+      node =
+          LogicalJoin.create(joinRelTemp.getLeft(),
+              joinRelTemp.getRight(),
+              joinRelTemp.getHints(),
+              joinRelTemp.getCondition(),
+              ImmutableSet.of(correlationUseInJoin.id),
+              joinRelTemp.getJoinType());
+    }
+
     // If join conditions are pushed down, update the leaves.
     if (node instanceof Project) {
       final Join newJoin = (Join) node.getInputs().get(0);
@@ -3377,7 +3390,7 @@ private void convertJoin(Blackboard bb, SqlJoin join) {
     }
     condition = simplifyPredicate(condition);
 
-    RelNode joinRel;
+    final RelNode joinRel;
     if (joinType == JoinType.ASOF || joinType == JoinType.LEFT_ASOF) {
       SqlNode sqlMatchCondition =
           requireNonNull(((SqlAsofJoin) join).getMatchCondition(),
@@ -3395,18 +3408,6 @@ private void convertJoin(Blackboard bb, SqlJoin join) {
       joinRel =
           createJoin(fromBlackboard, leftRel, rightRel, condition,
               convertJoinType(joinType));
-      final CorrelationUse p = getCorrelationUse(bb, joinRel);
-      if (joinRel instanceof Join && p != null) {
-        assert p.r instanceof Join;
-        Join joinRelTemp = (Join) p.r;
-        joinRel =
-            LogicalJoin.create(joinRelTemp.getLeft(),
-                joinRelTemp.getRight(),
-                joinRelTemp.getHints(),
-                joinRelTemp.getCondition(),
-                ImmutableSet.of(p.id),
-                joinRelTemp.getJoinType());
-      }
     }
     relBuilder.push(joinRel);
     relBuilder.project(relBuilder.fields());