From b3dc913a8c031cdacca58d4220e8912fcc1ed515 Mon Sep 17 00:00:00 2001
From: minghong <zhouminghong@selectdb.com>
Date: Thu, 7 Aug 2025 11:58:05 +0800
Subject: [PATCH 1/2] pick

---
 .../doris/nereids/stats/StatsCalculator.java      | 15 +++++++++++----
 .../java/org/apache/doris/qe/SessionVariable.java | 14 ++++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
index b088ed0dccfa46..9949cf3669e020 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
@@ -117,6 +117,7 @@
 import org.apache.doris.nereids.types.DataType;
 import org.apache.doris.nereids.types.coercion.CharacterType;
 import org.apache.doris.qe.ConnectContext;
+import org.apache.doris.qe.SessionVariable;
 import org.apache.doris.statistics.AnalysisManager;
 import org.apache.doris.statistics.ColumnStatistic;
 import org.apache.doris.statistics.ColumnStatisticBuilder;
@@ -1200,16 +1201,22 @@ public static Optional<String> disableJoinReorderIfStatsInvalid(List<CatalogRela
             double rowCount = calculator.getTableRowCount(scan);
             // row count not available
             if (rowCount == -1) {
-                LOG.info("disable join reorder since row count not available: "
-                        + scan.getTable().getNameWithFullQualifiers());
-                return Optional.of("table[" + scan.getTable().getName() + "] row count is invalid");
+                try {
+                    context.getConnectContext().getSessionVariable()
+                            .setVarOnce(SessionVariable.DISABLE_JOIN_REORDER, "true");
+                    LOG.info("disable join reorder since table row count is not available :"
+                            + scan.getTable().getName());
+                } catch (Exception e) {
+                    LOG.error("disable NereidsJoinReorderOnce failed", e);
+                }
             }
             if (scan instanceof OlapScan) {
                 // ndv abnormal
                 Optional<String> reason = calculator.checkNdvValidation((OlapScan) scan, rowCount);
                 if (reason.isPresent()) {
                     try {
-                        ConnectContext.get().getSessionVariable().disableNereidsJoinReorderOnce();
+                        ConnectContext.get().getSessionVariable()
+                                .setVarOnce(SessionVariable.DISABLE_JOIN_REORDER, "true");
                         LOG.info("disable join reorder since col stats invalid: "
                                 + reason.get());
                     } catch (Exception e) {
diff --git a/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java b/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java
index 515f90cd81f83d..4d7099983801a4 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java
@@ -3079,5 +3079,19 @@ public boolean isEnableCooldownReplicaAffinity() {
         return enableCooldownReplicaAffinity;
     }
 
+    /**
+     *
+     * @return true iff set success
+     */
+    public boolean setVarOnce(String varName, String value) {
+        try {
+            setIsSingleSetVar(true);
+            VariableMgr.setVar(this, new SetVar(varName, new StringLiteral(value)));
+            return true;
+        } catch (DdlException e) {
+            LOG.warn("set onece {} = {} failed", varName, value);
+            return false;
+        }
+    }
 }
 

From 0e93ffbe82bb1a64f15177d46d51d233c4941b35 Mon Sep 17 00:00:00 2001
From: minghong <zhouminghong@selectdb.com>
Date: Thu, 7 Aug 2025 12:32:20 +0800
Subject: [PATCH 2/2] fix

---
 .../java/org/apache/doris/nereids/stats/StatsCalculator.java     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
index 9949cf3669e020..103461b0008316 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java
@@ -1209,6 +1209,7 @@ public static Optional<String> disableJoinReorderIfStatsInvalid(List<CatalogRela
                 } catch (Exception e) {
                     LOG.error("disable NereidsJoinReorderOnce failed", e);
                 }
+                return Optional.of("table[" + scan.getTable().getName() + "] row count is invalid");
             }
             if (scan instanceof OlapScan) {
                 // ndv abnormal