Push down derived tables under route when possible

go/test/endtoend/vtgate/queries/derived/derived_test.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2022 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package misc
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"vitess.io/vitess/go/test/endtoend/cluster"
+	"vitess.io/vitess/go/test/endtoend/utils"
+)
+
+func start(t *testing.T) (utils.MySQLCompare, func()) {
+	mcmp, err := utils.NewMySQLCompare(t, vtParams, mysqlParams)
+	require.NoError(t, err)
+
+	deleteAll := func() {
+		tables := []string{"music"}
+		for _, table := range tables {
+			_, _ = mcmp.ExecAndIgnore("delete from " + table)
+		}
+	}
+
+	deleteAll()
+
+	return mcmp, func() {
+		deleteAll()
+		mcmp.Close()
+		cluster.PanicHandler(t)
+	}
+}
+
+func TestDerivedTableWithOrderByLimit(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into music(id, user_id) values(1,1), (2,5), (3,1), (4,2), (5,3), (6,4), (7,5)")
+	mcmp.Exec("insert into user(id, name) values(1,'toto'), (2,'tata'), (3,'titi'), (4,'tete'), (5,'foo')")
+
+	mcmp.Exec("select /*vt+ PLANNER=Gen4 */ music.id from music join (select id,name from user order by id limit 2) as d on music.user_id = d.id")
+}
+
+func TestDerivedAggregationOnRHS(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into music(id, user_id) values(1,1), (2,5), (3,1), (4,2), (5,3), (6,4), (7,5)")
+	mcmp.Exec("insert into user(id, name) values(1,'toto'), (2,'tata'), (3,'titi'), (4,'tete'), (5,'foo')")
+
+	mcmp.Exec("set sql_mode = ''")
+	mcmp.Exec("select /*vt+ PLANNER=Gen4 */ d.a from music join (select id, count(*) as a from user) as d on music.user_id = d.id group by 1")
+}
+
+func TestDerivedRemoveInnerOrderBy(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into music(id, user_id) values(1,1), (2,5), (3,1), (4,2), (5,3), (6,4), (7,5)")
+	mcmp.Exec("insert into user(id, name) values(1,'toto'), (2,'tata'), (3,'titi'), (4,'tete'), (5,'foo')")
+
+	mcmp.Exec("select /*vt+ PLANNER=Gen4 */ count(*) from (select user.id as oui, music.id as non from user join music on user.id = music.user_id order by user.name) as toto")
+}
+
+func TestDerivedTableWithHaving(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into music(id, user_id) values(1,1), (2,5), (3,1), (4,2), (5,3), (6,4), (7,5)")
+	mcmp.Exec("insert into user(id, name) values(1,'toto'), (2,'tata'), (3,'titi'), (4,'tete'), (5,'foo')")
+
+	mcmp.Exec("set sql_mode = ''")
+
+	// this is probably flaky? the id returned from the derived table could be any of the ids from user.
+	// works on my machine (TM)
+	mcmp.Exec("select  /*vt+ PLANNER=Gen4 */ * from (select id from user having count(*) >= 1) s")
+}
+
+func TestDerivedTableColumns(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into user(id, name) values(1,'toto'), (2,'tata'), (3,'titi'), (4,'tete'), (5,'foo')")
+	mcmp.AssertMatches(`SELECT /*vt+ PLANNER=gen4 */ t.id FROM (SELECT id FROM user) AS t(id) ORDER BY t.id DESC`, `[[INT64(5)] [INT64(4)] [INT64(3)] [INT64(2)] [INT64(1)]]`)
+}

go/test/endtoend/vtgate/mysql80/derived/main_test.go → go/test/endtoend/vtgate/queries/derived/main_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2021 The Vitess Authors.
+Copyright 2022 The Vitess Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,83 +14,41 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package derived
+package misc
 
 import (
+	_ "embed"
 	"flag"
+	"fmt"
 	"os"
 	"testing"
 
+	"vitess.io/vitess/go/test/endtoend/utils"
+
 	"vitess.io/vitess/go/mysql"
 	"vitess.io/vitess/go/test/endtoend/cluster"
 )
 
 var (
 	clusterInstance *cluster.LocalProcessCluster
 	vtParams        mysql.ConnParams
-	KeyspaceName    = "ks_union"
-	Cell            = "test_union"
-	SchemaSQL       = `create table t1(
-	id1 bigint,
-	id2 bigint,
-	primary key(id1)
-) Engine=InnoDB;
-
-create table t1_id2_idx(
-	id2 bigint,
-	keyspace_id varbinary(10),
-	primary key(id2)
-) Engine=InnoDB;
-`
-
-	VSchema = `
-{
-  "sharded": true,
-  "vindexes": {
-    "hash": {
-      "type": "hash"
-    },
-    "t1_id2_vdx": {
-      "type": "consistent_lookup_unique",
-      "params": {
-        "table": "t1_id2_idx",
-        "from": "id2",
-        "to": "keyspace_id"
-      },
-      "owner": "t1"
-    }
-  },
-  "tables": {
-    "t1": {
-      "column_vindexes": [
-        {
-          "column": "id1",
-          "name": "hash"
-        },
-        {
-          "column": "id2",
-          "name": "t1_id2_vdx"
-        }
-      ]
-    },
-    "t1_id2_idx": {
-      "column_vindexes": [
-        {
-          "column": "id2",
-          "name": "hash"
-        }
-      ]
-    }
-  }
-}`
+	mysqlParams     mysql.ConnParams
+	keyspaceName    = "ks_derived"
+	cell            = "test_derived"
+
+	//go:embed schema.sql
+	schemaSQL string
+
+	//go:embed vschema.json
+	vschema string
 )
 
 func TestMain(m *testing.M) {
 	defer cluster.PanicHandler(nil)
 	flag.Parse()
 
 	exitCode := func() int {
-		clusterInstance = cluster.NewCluster(Cell, "localhost")
+		clusterInstance = cluster.NewCluster(cell, "localhost")
 		defer clusterInstance.Teardown()
 
 		// Start topo server
@@ -101,12 +59,10 @@ func TestMain(m *testing.M) {
 
 		// Start keyspace
 		keyspace := &cluster.Keyspace{
-			Name:      KeyspaceName,
-			SchemaSQL: SchemaSQL,
-			VSchema:   VSchema,
+			Name:      keyspaceName,
+			SchemaSQL: schemaSQL,
+			VSchema:   vschema,
 		}
-		clusterInstance.VtGateExtraArgs = []string{"--schema_change_signal"}
-		clusterInstance.VtTabletExtraArgs = []string{"--queryserver-config-schema-change-signal", "--queryserver-config-schema-change-signal-interval", "0.1"}
 		err = clusterInstance.StartKeyspace(*keyspace, []string{"-80", "80-"}, 1, true)
 		if err != nil {
 			return 1
@@ -123,6 +79,15 @@ func TestMain(m *testing.M) {
 			Host: clusterInstance.Hostname,
 			Port: clusterInstance.VtgateMySQLPort,
 		}
+
+		// create mysql instance and connection parameters
+		conn, closer, err := utils.NewMySQL(clusterInstance, keyspaceName, schemaSQL)
+		if err != nil {
+			fmt.Println(err)
+			return 1
+		}
+		defer closer()
+		mysqlParams = conn
 		return m.Run()
 	}()
 	os.Exit(exitCode)

go/test/endtoend/vtgate/queries/derived/schema.sql

@@ -0,0 +1,13 @@
+create table user
+(
+    id            bigint,
+    name varchar(255),
+    primary key (id)
+) Engine = InnoDB;
+
+create table music
+(
+    id            bigint,
+    user_id bigint,
+    primary key (id)
+) Engine = InnoDB;

go/test/endtoend/vtgate/queries/derived/vschema.json

@@ -0,0 +1,26 @@
+{
+  "sharded": true,
+  "vindexes": {
+    "user_index": {
+      "type": "hash"
+    }
+  },
+  "tables": {
+    "user": {
+      "column_vindexes": [
+        {
+          "column": "id",
+          "name": "user_index"
+        }
+      ]
+    },
+    "music": {
+      "column_vindexes": [
+        {
+          "column": "user_id",
+          "name": "user_index"
+        }
+      ]
+    }
+  }
+}

go/vt/sqlparser/ast.go

@@ -56,12 +56,14 @@ type (
 		AddOrder(*Order)
 		SetOrderBy(OrderBy)
 		GetOrderBy() OrderBy
+		GetLimit() *Limit
 		SetLimit(*Limit)
 		SetLock(lock Lock)
 		SetInto(into *SelectInto)
 		SetWith(with *With)
 		MakeDistinct()
 		GetColumnCount() int
+		GetColumns() SelectExprs
 		Commented
 	}
 

go/vt/sqlparser/ast_funcs.go

@@ -852,6 +852,11 @@ func (node *Select) SetLimit(limit *Limit) {
 	node.Limit = limit
 }
 
+// GetLimit gets the limit
+func (node *Select) GetLimit() *Limit {
+	return node.Limit
+}
+
 // SetLock sets the lock clause
 func (node *Select) SetLock(lock Lock) {
 	node.Lock = lock
@@ -877,6 +882,11 @@ func (node *Select) GetColumnCount() int {
 	return len(node.SelectExprs)
 }
 
+// GetColumns gets the columns
+func (node *Select) GetColumns() SelectExprs {
+	return node.SelectExprs
+}
+
 // SetComments implements the SelectStatement interface
 func (node *Select) SetComments(comments Comments) {
 	node.Comments = comments.Parsed()
@@ -964,6 +974,16 @@ func (node *Union) SetLimit(limit *Limit) {
 	node.Limit = limit
 }
 
+// GetLimit gets the limit
+func (node *Union) GetLimit() *Limit {
+	return node.Limit
+}
+
+// GetColumns gets the columns
+func (node *Union) GetColumns() SelectExprs {
+	return node.Left.GetColumns()
+}
+
 // SetLock sets the lock clause
 func (node *Union) SetLock(lock Lock) {
 	node.Lock = lock