ds72-connectivity

englefly · Jul 29, 2024 · 766e5fa · 766e5fa
1 parent fe7b674
commit 766e5fa
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostModelV1.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostModelV1.java
@@ -349,13 +349,14 @@ public Cost visitPhysicalHashJoin(
 
         double leftRowCount = probeStats.getRowCount();
         double rightRowCount = buildStats.getRowCount();
+        int leftConnectivity = computeConnectivity(physicalHashJoin.left(), context);
+        int rightConnectivity = computeConnectivity(physicalHashJoin.right(), context);
+
         if ((long) leftRowCount == (long) rightRowCount) {
             // reorder by connectivity to be friendly to runtime filter.
             if (physicalHashJoin.getGroupExpression().isPresent()
                     && physicalHashJoin.getGroupExpression().get().getOwnerGroup() != null
                     && !physicalHashJoin.getGroupExpression().get().getOwnerGroup().isStatsReliable()) {
-                int leftConnectivity = computeConnectivity(physicalHashJoin.left(), context);
-                int rightConnectivity = computeConnectivity(physicalHashJoin.right(), context);
                 if (rightConnectivity < leftConnectivity) {
                     leftRowCount += 1;
                 }
@@ -371,6 +372,10 @@ public Cost visitPhysicalHashJoin(
                 leftRowCount += 1e-3;
             }
         }
+        if (!physicalHashJoin.getGroupExpression().get().getOwnerGroup().isStatsReliable()) {
+            // if a table with higher connectivity, move it to top-join. it is good for runtime filter.
+            leftRowCount -= rightConnectivity * probeStats.getWidthInJoinCluster();
+        }
 
         /*
         pattern1: L join1 (Agg1() join2 Agg2())