From 2c2d52bc1a01cdf22b4263629f9374a9ef5aa33b Mon Sep 17 00:00:00 2001
From: nitao <badboynt@126.com>
Date: Fri, 13 Sep 2024 00:53:56 +0800
Subject: [PATCH] support order by limit optimization for non-sorted columns
 (#18753)

support order by limit optimization for non-sorted columns

Approved by: @heni02, @aressu1985, @ouyuanning
---
 pkg/sql/plan/message.go                     |  3 ---
 test/distributed/cases/optimizer/top.result | 22 +++++++++++++++++++++
 test/distributed/cases/optimizer/top.test   |  3 +++
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/pkg/sql/plan/message.go b/pkg/sql/plan/message.go
index 82f71a65b9d8..8b4d7f1b8e67 100644
--- a/pkg/sql/plan/message.go
+++ b/pkg/sql/plan/message.go
@@ -78,9 +78,6 @@ func (builder *QueryBuilder) handleMessgaeFromTopToScan(nodeID int32) {
 	if orderByCol.Col.RelPos != scanNode.BindingTags[0] {
 		return
 	}
-	if GetSortOrder(scanNode.TableDef, orderByCol.Col.ColPos) != 0 {
-		return
-	}
 
 	msgTag := builder.genNewMsgTag()
 	msgHeader := &plan.MsgHeader{MsgTag: msgTag, MsgType: int32(message.MsgTopValue)}
diff --git a/test/distributed/cases/optimizer/top.result b/test/distributed/cases/optimizer/top.result
index b25276e52bd2..4ebc763b294a 100644
--- a/test/distributed/cases/optimizer/top.result
+++ b/test/distributed/cases/optimizer/top.result
@@ -172,6 +172,28 @@ c1    c2    c3    c1    c2    c3
 899983    899983    899983    899983    899983    899983
 899982    899982    899982    899982    899982    899982
 899981    899981    899981    899981    899981    899981
+explain select * from t1 order by c2 limit 10 offset 20;
+AP QUERY PLAN ON MULTICN(4 core)
+Project
+  ->  Sort
+        Sort Key: t1.c2 INTERNAL
+        Limit: 10, Offset: 20
+        Send Message: [tag 1 , type MsgTopValue]
+        ->  Table Scan on d1.t1
+              Sort Key: c2 INTERNAL
+              Recv Message: [tag 1 , type MsgTopValue]
+select * from t1 order by c2 limit 10 offset 20;
+c1    c2    c3
+21    21    21
+22    22    22
+23    23    23
+24    24    24
+25    25    25
+26    26    26
+27    27    27
+28    28    28
+29    29    29
+30    30    30
 drop table if exists t1;
 create table t1 (a int primary key, b int);
 insert into t1 select result, result from generate_series (1, 800000)g;
diff --git a/test/distributed/cases/optimizer/top.test b/test/distributed/cases/optimizer/top.test
index 4037b75d1d07..cfa67a173cf9 100644
--- a/test/distributed/cases/optimizer/top.test
+++ b/test/distributed/cases/optimizer/top.test
@@ -27,6 +27,9 @@ select * from t1,t2 where t1.c1=t2.c1 and t2.c2 between 33333 and 555555 order b
 -- @separator:table
 explain select * from t1,t2 where t1.c1=t2.c1  order by t1.c1 desc limit 10 offset 10;
 select * from t1,t2 where t1.c1=t2.c1 and t2.c2  order by t1.c1 desc limit 10 offset 10;
+-- @separator:table
+explain select * from t1 order by c2 limit 10 offset 20;
+select * from t1 order by c2 limit 10 offset 20;
 drop table if exists t1;
 create table t1 (a int primary key, b int);
 insert into t1 select result, result from generate_series (1, 800000)g;