[CALCITE-5832] Avoid cycle in relational nodes.

sap-contributions · Dec 13, 2023 · 34f2b3d · 34f2b3d
1 parent a6729b7
commit 34f2b3d
Showing 1 changed file with 11 additions and 17 deletions.
diff --git a/core/src/main/java/org/apache/calcite/plan/volcano/VolcanoPlanner.java b/core/src/main/java/org/apache/calcite/plan/volcano/VolcanoPlanner.java
@@ -70,17 +70,7 @@
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
-import java.util.ArrayDeque;
-import java.util.ArrayList;
-import java.util.Deque;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.IdentityHashMap;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.PriorityQueue;
-import java.util.Set;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -1107,13 +1097,17 @@ private boolean fixUpInputs(RelNode rel) {
       assert input instanceof RelSubset;
       final RelSubset subset = (RelSubset) input;
       RelSubset newSubset = canonize(subset);
-      newInputs.add(newSubset);
-      if (newSubset != subset) {
-        if (subset.set != newSubset.set) {
-          subset.set.parents.remove(rel);
-          newSubset.set.parents.add(rel);
+      if ( rel == subset.best) {
+        newInputs.add(input);
+      } else {
+        newInputs.add(newSubset);
+        if (newSubset != subset) {
+          if (subset.set != newSubset.set) {
+            subset.set.parents.remove(rel);
+            newSubset.set.parents.add(rel);
+          }
+          changeCount++;
         }
-        changeCount++;
       }
     }