From 0cddaf4699bb1e75e46c8fd981f4677918c0c662 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Thu, 8 Jun 2023 20:49:02 +0800
Subject: [PATCH 1/8] fixup

---
 .../clustertablestest/cluster_tables_test.go  | 134 ++++++++++++++++++
 1 file changed, 134 insertions(+)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index bbe0bfc891376..7285cd4c2286d 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -879,6 +879,140 @@ func TestMDLView(t *testing.T) {
 	}
 }
 
+func TestQuickBinding(t *testing.T) {
+	s := new(clusterTablesSuite)
+	s.store, s.dom = testkit.CreateMockStoreAndDomain(t)
+	s.rpcserver, s.listenAddr = s.setUpRPCService(t, "127.0.0.1:0", nil)
+	s.httpServer, s.mockAddr = s.setUpMockPDHTTPServer()
+	s.startTime = time.Now()
+	defer s.httpServer.Close()
+	defer s.rpcserver.Stop()
+	tk := s.newTestKitWithRoot(t)
+	require.NoError(t, tk.Session().Auth(&auth.UserIdentity{Username: "root", Hostname: "%"}, nil, nil, nil))
+
+	tk.MustExec("use test")
+	tk.MustExec(`create table t1 (pk int, a int, b int, c int, primary key(pk), key k_a(a), key k_bc(b, c))`)
+
+	type testCase struct {
+		template                string
+		expectedHint            string
+		dmlAndSubqueryTemplates []string
+	}
+	defaultDMLAndSubqueryTemplates := []string{
+		//"select a from (%v) tx where tx.a<1", // TODO: support sub query
+		"insert into t1 %v",
+		// TODO: more templates
+	}
+	testCases := []testCase{
+		{`select /*+ use_index(t1, k_a) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_a) */ * from t1 where a<?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_a) */ * from t1 where a in (?, ?, ?) and b<?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_bc) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_bc) */ * from t1 where a<?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_bc) */ * from t1 where a in (?, ?, ?) and b<?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
+	}
+
+	removeHint := func(sql string) string {
+		b := strings.Index(sql, "/*+")
+		e := strings.Index(sql, "*/")
+		if b != -1 && e != -1 {
+			sql = sql[:b] + sql[e+2:]
+		}
+		return sql
+	}
+	randValue := func() string {
+		switch rand.Intn(4) {
+		case 0:
+			return "0"
+		case 1:
+			return "-9999999999999"
+		case 2:
+			return "9999999999999"
+		default:
+			width := 100000
+			return strconv.Itoa(width - rand.Intn(width*2))
+		}
+	}
+	fillValues := func(sql string) string {
+		for strings.Contains(sql, "?") {
+			sql = strings.Replace(sql, "?", randValue(), 1)
+		}
+		return sql
+	}
+	genPrepSQL := func(sql string) (prepStmt, setStmt, execStmt string) {
+		sql = removeHint(sql)
+		prepStmt = fmt.Sprintf("prepare st from '%v'", sql)
+		nParam := strings.Count(sql, "?")
+		var x, y []string
+		for i := 0; i < nParam; i++ {
+			x = append(x, fmt.Sprintf("@a%d=%v", i, randValue()))
+			y = append(y, fmt.Sprintf("@a%d", i))
+		}
+		setStmt = fmt.Sprintf("set %v", strings.Join(x, ", "))
+		execStmt = fmt.Sprintf("execute st using %v", strings.Join(y, ", "))
+		return
+	}
+
+	// test general queries and prepared / execute statements
+	for _, tc := range testCases {
+		stmtsummary.StmtSummaryByDigestMap.Clear()
+		firstSQL := fillValues(tc.template)
+		tk.MustExec(firstSQL)
+		result := tk.MustQuery(`select plan_hint, digest, plan_digest from information_schema.statements_summary`).Rows()
+		planHint, sqlDigest, planDigest := result[0][0].(string), result[0][1].(string), result[0][2].(string)
+		require.Equal(t, tc.expectedHint, planHint)
+		tk.MustExec(fmt.Sprintf(`create session binding from history using plan digest '%v'`, planDigest))
+
+		// normal test
+		sqlWithoutHint := removeHint(tc.template)
+		for i := 0; i < 5; i++ {
+			stmtsummary.StmtSummaryByDigestMap.Clear()
+			testSQL := fillValues(sqlWithoutHint)
+			tk.MustExec(testSQL)
+			tk.MustQuery(`select @@last_plan_from_binding`).Check(testkit.Rows("1"))
+			// has the same plan-digest
+			tk.MustQuery(fmt.Sprintf(`select plan_digest from information_schema.statements_summary where digest='%v'`, sqlDigest)).Check(testkit.Rows(planDigest))
+		}
+
+		// test with prepared / execute protocol
+		for i := 0; i < 5; i++ {
+			stmtsummary.StmtSummaryByDigestMap.Clear()
+			prepStmt, setStmt, execStmt := genPrepSQL(tc.template)
+			tk.MustExec(prepStmt)
+			tk.MustExec(setStmt)
+			tk.MustExec(execStmt)
+			tk.MustQuery(`select @@last_plan_from_binding`).Check(testkit.Rows("1"))
+			// has the same plan-digest
+			tk.MustQuery(fmt.Sprintf(`select plan_digest from information_schema.statements_summary where digest='%v'`, sqlDigest)).Check(testkit.Rows(planDigest))
+		}
+
+		tk.MustExec(fmt.Sprintf(`drop session binding for %s`, firstSQL))
+	}
+
+	for _, tc := range testCases {
+		for _, temp := range tc.dmlAndSubqueryTemplates {
+			temp = fmt.Sprintf(temp, tc.template)
+			stmtsummary.StmtSummaryByDigestMap.Clear()
+			firstSQL := fillValues(tc.template)
+			tk.MustExec(firstSQL)
+			result := tk.MustQuery(`select plan_hint, digest, plan_digest from information_schema.statements_summary`).Rows()
+			_, sqlDigest, planDigest := result[0][0].(string), result[0][1].(string), result[0][2].(string)
+			tk.MustExec(fmt.Sprintf(`create session binding from history using plan digest '%v'`, planDigest))
+
+			// normal test
+			sqlWithoutHint := removeHint(tc.template)
+			for i := 0; i < 5; i++ {
+				stmtsummary.StmtSummaryByDigestMap.Clear()
+				testSQL := fillValues(sqlWithoutHint)
+				tk.MustExec(testSQL)
+				tk.MustQuery(`select @@last_plan_from_binding`).Check(testkit.Rows("1"))
+				// has the same plan-digest
+				tk.MustQuery(fmt.Sprintf(`select plan_digest from information_schema.statements_summary where digest='%v'`, sqlDigest)).Check(testkit.Rows(planDigest))
+			}
+		}
+	}
+}
+
 func TestCreateBindingFromHistory(t *testing.T) {
 	s := new(clusterTablesSuite)
 	s.store, s.dom = testkit.CreateMockStoreAndDomain(t)

From 5849a0c55eac8bfd64a68aff8a2f406d9c4f1519 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 12:10:41 +0800
Subject: [PATCH 2/8] fixup

---
 infoschema/test/clustertablestest/cluster_tables_test.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index 7285cd4c2286d..dbec1a6a76417 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -989,6 +989,7 @@ func TestQuickBinding(t *testing.T) {
 		tk.MustExec(fmt.Sprintf(`drop session binding for %s`, firstSQL))
 	}
 
+	// test with DML and sub-query
 	for _, tc := range testCases {
 		for _, temp := range tc.dmlAndSubqueryTemplates {
 			temp = fmt.Sprintf(temp, tc.template)
@@ -1009,6 +1010,8 @@ func TestQuickBinding(t *testing.T) {
 				// has the same plan-digest
 				tk.MustQuery(fmt.Sprintf(`select plan_digest from information_schema.statements_summary where digest='%v'`, sqlDigest)).Check(testkit.Rows(planDigest))
 			}
+
+			tk.MustExec(fmt.Sprintf(`drop session binding for %s`, firstSQL))
 		}
 	}
 }

From 6402afa5636278c8ea805557db48101669920241 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 12:20:17 +0800
Subject: [PATCH 3/8] fixup

---
 .../test/clustertablestest/cluster_tables_test.go   | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index dbec1a6a76417..652fb3a36c99e 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -892,6 +892,7 @@ func TestQuickBinding(t *testing.T) {
 
 	tk.MustExec("use test")
 	tk.MustExec(`create table t1 (pk int, a int, b int, c int, primary key(pk), key k_a(a), key k_bc(b, c))`)
+	tk.MustExec(`create table t2 (a int, b int, c int, key k_a(a), key k_bc(b, c))`) // no primary key
 
 	type testCase struct {
 		template                string
@@ -904,12 +905,12 @@ func TestQuickBinding(t *testing.T) {
 		// TODO: more templates
 	}
 	testCases := []testCase{
-		{`select /*+ use_index(t1, k_a) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
-		{`select /*+ use_index(t1, k_a) */ * from t1 where a<?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
-		{`select /*+ use_index(t1, k_a) */ * from t1 where a in (?, ?, ?) and b<?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
-		{`select /*+ use_index(t1, k_bc) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
-		{`select /*+ use_index(t1, k_bc) */ * from t1 where a<?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
-		{`select /*+ use_index(t1, k_bc) */ * from t1 where a in (?, ?, ?) and b<?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
+		// access path selection with use_index
+		{`select /*+ use_index(t1, k_a) */ * from t1 where b=?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, k_bc) */ * from t1 where a=?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1, primary) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` )", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t1) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` )", defaultDMLAndSubqueryTemplates},
+		{`select /*+ use_index(t2) */ * from t2 where a=? and b=?`, "use_index(@`sel_1` `test`.`t2` )", nil},
 	}
 
 	removeHint := func(sql string) string {

From 1106d7068e19f6cb903915b57d7fd3d25dea9bb2 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 12:27:58 +0800
Subject: [PATCH 4/8] fixup

---
 infoschema/test/clustertablestest/cluster_tables_test.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index 652fb3a36c99e..180c3aa0f8534 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -905,10 +905,11 @@ func TestQuickBinding(t *testing.T) {
 		// TODO: more templates
 	}
 	testCases := []testCase{
-		// access path selection with use_index
+		// access path selection with use_index / ignore_index
 		{`select /*+ use_index(t1, k_a) */ * from t1 where b=?`, "use_index(@`sel_1` `test`.`t1` `k_a`)", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t1, k_bc) */ * from t1 where a=?`, "use_index(@`sel_1` `test`.`t1` `k_bc`)", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t1, primary) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` )", defaultDMLAndSubqueryTemplates},
+		{`select /*+ ignore_index(t1, k_a, k_bc) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` ), ignore_index(`t1` `k_a`, `k_bc`)", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t1) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` )", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t2) */ * from t2 where a=? and b=?`, "use_index(@`sel_1` `test`.`t2` )", nil},
 	}

From c68a6561012614fd35c58c6f4f984b0d8b870972 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 14:39:45 +0800
Subject: [PATCH 5/8] fixup

---
 infoschema/test/clustertablestest/cluster_tables_test.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index 180c3aa0f8534..4fafb29f72ef2 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -996,14 +996,14 @@ func TestQuickBinding(t *testing.T) {
 		for _, temp := range tc.dmlAndSubqueryTemplates {
 			temp = fmt.Sprintf(temp, tc.template)
 			stmtsummary.StmtSummaryByDigestMap.Clear()
-			firstSQL := fillValues(tc.template)
+			firstSQL := fillValues(temp)
 			tk.MustExec(firstSQL)
 			result := tk.MustQuery(`select plan_hint, digest, plan_digest from information_schema.statements_summary`).Rows()
 			_, sqlDigest, planDigest := result[0][0].(string), result[0][1].(string), result[0][2].(string)
 			tk.MustExec(fmt.Sprintf(`create session binding from history using plan digest '%v'`, planDigest))
 
 			// normal test
-			sqlWithoutHint := removeHint(tc.template)
+			sqlWithoutHint := removeHint(temp)
 			for i := 0; i < 5; i++ {
 				stmtsummary.StmtSummaryByDigestMap.Clear()
 				testSQL := fillValues(sqlWithoutHint)

From 44a2f94ad6df1c8e282a29b3a2f2f5998bafb751 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 15:15:07 +0800
Subject: [PATCH 6/8] fixup

---
 infoschema/test/clustertablestest/cluster_tables_test.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index 4fafb29f72ef2..ff7a44025f91d 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -912,6 +912,12 @@ func TestQuickBinding(t *testing.T) {
 		{`select /*+ ignore_index(t1, k_a, k_bc) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` ), ignore_index(`t1` `k_a`, `k_bc`)", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t1) */ * from t1 where a=? and b=?`, "use_index(@`sel_1` `test`.`t1` )", defaultDMLAndSubqueryTemplates},
 		{`select /*+ use_index(t2) */ * from t2 where a=? and b=?`, "use_index(@`sel_1` `test`.`t2` )", nil},
+
+		// aggregation
+		{`select /*+ hash_agg(), use_index(t1, primary) */ count(*) from t1 where a<?`, "hash_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
+		{`select /*+ hash_agg(), use_index(t1, primary) */ count(*), b from t1 where a<? group by b`, "hash_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
+		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*) from t1 where a<?`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
+		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*), b from t1 where a<? group by b`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
 	}
 
 	removeHint := func(sql string) string {

From a4092c5f4607fff743bb630eadbb451ae95909f5 Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 15:19:21 +0800
Subject: [PATCH 7/8] fixup

---
 infoschema/test/clustertablestest/cluster_tables_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index ff7a44025f91d..ea4335636bede 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -918,6 +918,7 @@ func TestQuickBinding(t *testing.T) {
 		{`select /*+ hash_agg(), use_index(t1, primary) */ count(*), b from t1 where a<? group by b`, "hash_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
 		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*) from t1 where a<?`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
 		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*), b from t1 where a<? group by b`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
+		{`select a+b+? from (select /*+ stream_agg() */ count(*) as a from t1) tt1, (select /*+ hash_agg() */ count(*) as b from t1) tt2`, "stream_agg(@`sel_2`), use_index(@`sel_2` `test`.`t1` `k_a`), hash_agg(@`sel_3`), use_index(@`sel_3` `test`.`t1` `k_a`)", nil},
 	}
 
 	removeHint := func(sql string) string {

From de2209105b195fdf19e1145a13043e57d8d2205c Mon Sep 17 00:00:00 2001
From: qw4990 <zhangyuanjia@pingcap.com>
Date: Fri, 9 Jun 2023 15:47:28 +0800
Subject: [PATCH 8/8] fixup

---
 .../test/clustertablestest/cluster_tables_test.go    | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/infoschema/test/clustertablestest/cluster_tables_test.go b/infoschema/test/clustertablestest/cluster_tables_test.go
index ea4335636bede..05abcc6dac68a 100644
--- a/infoschema/test/clustertablestest/cluster_tables_test.go
+++ b/infoschema/test/clustertablestest/cluster_tables_test.go
@@ -919,6 +919,18 @@ func TestQuickBinding(t *testing.T) {
 		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*) from t1 where a<?`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
 		{`select /*+ stream_agg(), use_index(t1, primary) */ count(*), b from t1 where a<? group by b`, "stream_agg(@`sel_1`), use_index(@`sel_1` `test`.`t1` )", nil},
 		{`select a+b+? from (select /*+ stream_agg() */ count(*) as a from t1) tt1, (select /*+ hash_agg() */ count(*) as b from t1) tt2`, "stream_agg(@`sel_2`), use_index(@`sel_2` `test`.`t1` `k_a`), hash_agg(@`sel_3`), use_index(@`sel_3` `test`.`t1` `k_a`)", nil},
+
+		// 2-way hash joins
+		{`select /*+ hash_join(t1, t2), use_index(t1), use_index(t2) */ t1.* from t1, t2 where t1.a=t2.a and t1.a<?`, "hash_join(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+		// not support, fix them later on
+		//{`select /*+ hash_join_build(t1), use_index(t1), use_index(t2) */ * from t1, t2 where t1.a=t2.a and t1.a<?`, "hash_join_build(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+		//{`select /*+ hash_join_build(t2), use_index(t1), use_index(t2) */ * from t1, t2 where t1.a=t2.a and t1.a<?`, "hash_join_build(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+		//{`select /*+ hash_join_probe(t1), use_index(t1), use_index(t2) */ * from t1, t2 where t1.a=t2.a and t1.a<?`, "hash_join_build(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+		//{`select /*+ hash_join_probe(t2), use_index(t1), use_index(t2) */ * from t1, t2 where t1.a=t2.a and t1.a<?`, "hash_join_build(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+
+		// 2-way merge joins
+		{`select /*+ merge_join(t1, t2), use_index(t1), use_index(t2) */ t1.* from t1, t2 where t1.a=t2.a and t1.a<?`, "merge_join(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` ), use_index(@`sel_1` `test`.`t2` )", nil},
+		{`select /*+ merge_join(t1, t2), use_index(t1, k_a), use_index(t2, k_a) */ t1.* from t1, t2 where t1.a=t2.a and t1.a<?`, "merge_join(@`sel_1` `test`.`t1`), use_index(@`sel_1` `test`.`t1` `k_a`), use_index(@`sel_1` `test`.`t2` `k_a`)", nil},
 	}
 
 	removeHint := func(sql string) string {