From abbd2cedff0760078a7c3253e2aa4066fadfca4c Mon Sep 17 00:00:00 2001
From: morrySnow <101034200+morrySnow@users.noreply.github.com>
Date: Wed, 27 Dec 2023 21:04:00 +0800
Subject: [PATCH] [fix](Nereids) merge limit should use bottom phase (#29142)

---
 .../nereids/rules/rewrite/MergeLimits.java    |  2 +-
 .../rules/rewrite/MergeLimitsTest.java        | 50 +++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/MergeLimits.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/MergeLimits.java
index 0621e70b70..e1428983c1 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/MergeLimits.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/MergeLimits.java
@@ -50,7 +50,7 @@ public class MergeLimits extends OneRewriteRuleFactory {
                             Math.min(upperLimit.getLimit(),
                                     Math.max(bottomLimit.getLimit() - upperLimit.getOffset(), 0)),
                             bottomLimit.getOffset() + upperLimit.getOffset(),
-                            upperLimit.getPhase(), bottomLimit.child()
+                            upperLimit.child().getPhase(), bottomLimit.child()
                     );
                 }).toRule(RuleType.MERGE_LIMITS);
     }
diff --git a/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/MergeLimitsTest.java b/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/MergeLimitsTest.java
index 9fcfd03e41..dbaeef6d79 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/MergeLimitsTest.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/MergeLimitsTest.java
@@ -17,6 +17,8 @@
 
 package org.apache.doris.nereids.rules.rewrite;
 
+import org.apache.doris.nereids.trees.plans.LimitPhase;
+import org.apache.doris.nereids.trees.plans.logical.LogicalLimit;
 import org.apache.doris.nereids.trees.plans.logical.LogicalOlapScan;
 import org.apache.doris.nereids.trees.plans.logical.LogicalPlan;
 import org.apache.doris.nereids.util.LogicalPlanBuilder;
@@ -44,4 +46,52 @@ class MergeLimitsTest implements MemoPatternMatchSupported {
                 .matches(
                         logicalLimit().when(limit -> limit.getLimit() == 2).when(limit -> limit.getOffset() == 5));
     }
+
+    @Test
+    void testMergeLimitsWithLocalUpperAndGlobalBottom() {
+        LogicalPlan logicalLimit = new LogicalLimit<>(2, 0, LimitPhase.LOCAL,
+                new LogicalLimit<>(10, 0, LimitPhase.GLOBAL, scan1));
+
+        PlanChecker.from(new ConnectContext(), logicalLimit).applyTopDown(new MergeLimits())
+                .matches(
+                        logicalLimit().when(limit -> limit.getLimit() == 2)
+                                .when(limit -> limit.getPhase() == LimitPhase.GLOBAL));
+    }
+
+    @Test
+    void testMergeLimitsWithLocalUpperAndLocalBottom() {
+        LogicalPlan logicalLimit = new LogicalLimit<>(2, 0, LimitPhase.LOCAL,
+                new LogicalLimit<>(10, 0, LimitPhase.LOCAL, scan1));
+
+        PlanChecker.from(new ConnectContext(), logicalLimit).applyTopDown(new MergeLimits())
+                .matches(
+                        logicalLimit().when(limit -> limit.getLimit() == 2)
+                                .when(limit -> limit.getPhase() == LimitPhase.LOCAL));
+    }
+
+    @Test
+    void testMergeLimitsWithGlobalUpperAndGlobalBottom() {
+        LogicalPlan logicalLimit = new LogicalLimit<>(2, 0, LimitPhase.GLOBAL,
+                new LogicalLimit<>(10, 0, LimitPhase.GLOBAL, scan1));
+
+        PlanChecker.from(new ConnectContext(), logicalLimit).applyTopDown(new MergeLimits())
+                .matches(
+                        logicalLimit().when(limit -> limit.getLimit() == 2)
+                                .when(limit -> limit.getPhase() == LimitPhase.GLOBAL));
+    }
+
+    @Test
+    void testMergeLimitsWithGlobalUpperAndLocalBottom() {
+        LogicalPlan logicalLimit = new LogicalLimit<>(2, 0, LimitPhase.GLOBAL,
+                new LogicalLimit<>(10, 0, LimitPhase.LOCAL, scan1));
+
+        PlanChecker.from(new ConnectContext(), logicalLimit).applyTopDown(new MergeLimits())
+                .matches(
+                        logicalLimit(
+                                logicalLimit()
+                                        .when(limit -> limit.getLimit() == 10)
+                                        .when(limit -> limit.getPhase() == LimitPhase.LOCAL))
+                                .when(limit -> limit.getLimit() == 2)
+                                .when(limit -> limit.getPhase() == LimitPhase.GLOBAL));
+    }
 }