From 223d7a36ebdad1436e11a43fc2d3d9fac2feca64 Mon Sep 17 00:00:00 2001
From: minghong <englefly@gmail.com>
Date: Mon, 20 Mar 2023 13:04:29 +0800
Subject: [PATCH] adjust distribution stats derive, fix bug in join estimation
 (#17916)

---
 .../doris/nereids/cost/CostModelV1.java       | 23 +++++++++----------
 .../org/apache/doris/nereids/cost/CostV1.java |  5 ++--
 .../doris/nereids/stats/JoinEstimation.java   |  4 ++--
 3 files changed, 16 insertions(+), 16 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
index e415543bfa..e36a1b2aa6 100644
--- 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
@@ -60,8 +60,12 @@ class CostModelV1 extends PlanVisitor<Cost, PlanContext> {
 
     public static Cost addChildCost(Plan plan, Cost planCost, Cost childCost, int index) {
         Preconditions.checkArgument(childCost instanceof CostV1 && planCost instanceof CostV1);
-        double cost = planCost.getValue() + childCost.getValue();
-        return new CostV1(cost);
+        CostV1 childCostV1 = (CostV1) childCost;
+        CostV1 planCostV1 = (CostV1) planCost;
+        return new CostV1(childCostV1.getCpuCost() + planCostV1.getCpuCost(),
+                childCostV1.getMemoryCost() + planCostV1.getMemoryCost(),
+                childCostV1.getNetworkCost() + planCostV1.getNetworkCost(),
+                childCostV1.getPenalty() + planCostV1.getPenalty());
     }
 
     @Override
@@ -170,22 +174,17 @@ class CostModelV1 extends PlanVisitor<Cost, PlanContext> {
                     || childStatistics.getRowCount() > rowsLimit) {
                 return CostV1.of(Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE);
             }
-            /*
-            TODO：
-            srcBeNum and destBeNum are not available, assume destBeNum/srcBeNum = 1
-            1. cpu: row * destBeNum/srcBeNum
-            2. network: rows send = rows/srcBeNum * destBeNum.
-             */
             return CostV1.of(
-                    childStatistics.getRowCount(), // TODO:should multiply by destBeNum/srcBeNum
-                    childStatistics.getRowCount(), // only consider one BE, not the whole system.
-                    childStatistics.getRowCount() * instanceNumber); // TODO: remove instanceNumber when BE updated
+                    0,
+                    0,
+                    childStatistics.getRowCount());
+
         }
 
         // gather
         if (spec instanceof DistributionSpecGather) {
             return CostV1.of(
-                    childStatistics.getRowCount(),
+                    0,
                     0,
                     childStatistics.getRowCount());
         }
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostV1.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostV1.java
index 0b425d91c8..2747346390 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostV1.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/cost/CostV1.java
@@ -105,8 +105,9 @@ class CostV1 implements Cost {
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
-        sb.append((long) cpuCost).append("/").append((long) memoryCost).append("/").append((long) networkCost)
-                .append("/").append((long) penalty);
+        sb.append(cost).append("[").append((long) cpuCost).append("/")
+                .append((long) memoryCost).append("/").append((long) networkCost)
+                .append("/").append((long) penalty).append("]");
         return sb.toString();
     }
 }
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java
index e77c060bba..0e8516e00c 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java
@@ -39,9 +39,9 @@ public class JoinEstimation {
                 .sorted((a, b) -> {
                     double sub = a.second - b.second;
                     if (sub > 0) {
-                        return -1;
-                    } else if (sub < 0) {
                         return 1;
+                    } else if (sub < 0) {
+                        return -1;
                     } else {
                         return 0;
                     }