planner: update some UTs from cost model1 to model2

executor/explainfor_test.go

@@ -443,6 +443,7 @@ func TestPointGetUserVarPlanCache(t *testing.T) {
 	tk.Session().Auth(&auth.UserIdentity{Username: "root", Hostname: "localhost", CurrentUser: true, AuthUsername: "root", AuthHostname: "%"}, nil, []byte("012345678901234567890"))
 
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("set @@tidb_enable_collect_execution_info=0;")
 	tk.Session().GetSessionVars().EnableClusteredIndex = variable.ClusteredIndexDefModeOn
 	tk.MustExec("drop table if exists t1")
@@ -461,12 +462,12 @@ func TestPointGetUserVarPlanCache(t *testing.T) {
 	tk.Session().SetSessionManager(&testkit.MockSessionManager{PS: ps})
 	tk.MustQuery(fmt.Sprintf("explain for connection %d", tkProcess.ID)).Check(testkit.Rows( // can use idx_a
 		`Projection_9 1.00 root  test.t1.a, test.t1.b, test.t2.a, test.t2.b`,
-		`└─IndexJoin_17 1.00 root  inner join, inner:TableReader_13, outer key:test.t2.a, inner key:test.t1.a, equal cond:eq(test.t2.a, test.t1.a)`,
-		`  ├─Selection_44(Build) 0.80 root  not(isnull(test.t2.a))`,
-		`  │ └─Point_Get_43 1.00 root table:t2, index:idx_a(a) `,
-		`  └─TableReader_13(Probe) 0.00 root  data:Selection_12`,
-		`    └─Selection_12 0.00 cop[tikv]  eq(test.t1.a, 1)`,
-		`      └─TableRangeScan_11 0.80 cop[tikv] table:t1 range: decided by [eq(test.t1.a, test.t2.a)], keep order:false, stats:pseudo`))
+		`└─MergeJoin_10 1.00 root  inner join, left key:test.t2.a, right key:test.t1.a`,
+		`  ├─Selection_42(Build) 10.00 root  eq(test.t1.a, 1)`,
+		`  │ └─TableReader_41 10.00 root  data:TableRangeScan_40`,
+		`  │   └─TableRangeScan_40 10.00 cop[tikv] table:t1 range:[1,1], keep order:true, stats:pseudo`,
+		`  └─Selection_39(Probe) 0.80 root  not(isnull(test.t2.a))`,
+		`    └─Point_Get_38 1.00 root table:t2, index:idx_a(a) `))
 
 	tk.MustExec("set @a=2")
 	tk.MustQuery("execute stmt using @a").Check(testkit.Rows(
@@ -477,12 +478,12 @@ func TestPointGetUserVarPlanCache(t *testing.T) {
 	tk.Session().SetSessionManager(&testkit.MockSessionManager{PS: ps})
 	tk.MustQuery(fmt.Sprintf("explain for connection %d", tkProcess.ID)).Check(testkit.Rows( // can use idx_a
 		`Projection_9 1.00 root  test.t1.a, test.t1.b, test.t2.a, test.t2.b`,
-		`└─IndexJoin_17 1.00 root  inner join, inner:TableReader_13, outer key:test.t2.a, inner key:test.t1.a, equal cond:eq(test.t2.a, test.t1.a)`,
-		`  ├─Selection_44(Build) 0.80 root  not(isnull(test.t2.a))`,
-		`  │ └─Point_Get_43 1.00 root table:t2, index:idx_a(a) `,
-		`  └─TableReader_13(Probe) 0.00 root  data:Selection_12`,
-		`    └─Selection_12 0.00 cop[tikv]  eq(test.t1.a, 2)`,
-		`      └─TableRangeScan_11 0.80 cop[tikv] table:t1 range: decided by [eq(test.t1.a, test.t2.a)], keep order:false, stats:pseudo`))
+		`└─MergeJoin_10 1.00 root  inner join, left key:test.t2.a, right key:test.t1.a`,
+		`  ├─Selection_42(Build) 10.00 root  eq(test.t1.a, 2)`,
+		`  │ └─TableReader_41 10.00 root  data:TableRangeScan_40`,
+		`  │   └─TableRangeScan_40 10.00 cop[tikv] table:t1 range:[2,2], keep order:true, stats:pseudo`,
+		`  └─Selection_39(Probe) 0.80 root  not(isnull(test.t2.a))`,
+		`    └─Point_Get_38 1.00 root table:t2, index:idx_a(a) `))
 	tk.MustQuery("execute stmt using @a").Check(testkit.Rows(
 		"2 4 2 2",
 	))

executor/showtest/show_test.go

@@ -775,6 +775,7 @@ func TestShowWarningsForExprPushdown(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec(`set tidb_cost_model_version=2`)
 	testSQL := `create table if not exists show_warnings_expr_pushdown (a int, value date)`
 	tk.MustExec(testSQL)
 
@@ -796,10 +797,10 @@ func TestShowWarningsForExprPushdown(t *testing.T) {
 	tk.MustExec("explain select * from show_warnings_expr_pushdown t where md5(value) = '2020-01-01'")
 	require.Equal(t, uint16(1), tk.Session().GetSessionVars().StmtCtx.WarningCount())
 	tk.MustQuery("show warnings").Check(testkit.RowsWithSep("|", "Warning|1105|Scalar function 'md5'(signature: MD5, return type: var_string(32)) is not supported to push down to tiflash now."))
-	tk.MustExec("explain select max(md5(value)) from show_warnings_expr_pushdown group by a")
+	tk.MustExec("explain select /*+ read_from_storage(tiflash[show_warnings_expr_pushdown]) */ max(md5(value)) from show_warnings_expr_pushdown group by a")
 	require.Equal(t, uint16(2), tk.Session().GetSessionVars().StmtCtx.WarningCount())
 	tk.MustQuery("show warnings").Check(testkit.RowsWithSep("|", "Warning|1105|Scalar function 'md5'(signature: MD5, return type: var_string(32)) is not supported to push down to tiflash now.", "Warning|1105|Aggregation can not be pushed to tiflash because arguments of AggFunc `max` contains unsupported exprs"))
-	tk.MustExec("explain select max(a) from show_warnings_expr_pushdown group by md5(value)")
+	tk.MustExec("explain select /*+ read_from_storage(tiflash[show_warnings_expr_pushdown]) */ max(a) from show_warnings_expr_pushdown group by md5(value)")
 	require.Equal(t, uint16(2), tk.Session().GetSessionVars().StmtCtx.WarningCount())
 	tk.MustQuery("show warnings").Check(testkit.RowsWithSep("|", "Warning|1105|Scalar function 'md5'(signature: MD5, return type: var_string(32)) is not supported to push down to tiflash now.", "Warning|1105|Aggregation can not be pushed to tiflash because groupByItems contain unsupported exprs"))
 	tk.MustExec("set tidb_opt_distinct_agg_push_down=0")

planner/core/cbo_test.go

@@ -264,6 +264,7 @@ func TestEmptyTable(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	testKit := testkit.NewTestKit(t, store)
 	testKit.MustExec("use test")
+	testKit.MustExec("set tidb_cost_model_version=2")
 	testKit.MustExec("drop table if exists t, t1")
 	testKit.MustExec("create table t (c1 int)")
 	testKit.MustExec("create table t1 (c1 int)")

planner/core/expression_rewriter_test.go

@@ -381,6 +381,7 @@ func TestMultiColInExpression(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test;")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists t1, t2")
 	tk.MustExec("create table t1(a int, b int)")
 	tk.MustExec("insert into t1 values(1,1),(2,null),(null,3),(4,4)")

planner/core/integration_test.go

@@ -615,6 +615,7 @@ func TestMPPJoin(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists d1_t")
 	tk.MustExec("create table d1_t(d1_k int, value int)")
 	tk.MustExec("insert into d1_t values(1,2),(2,3)")
@@ -6083,6 +6084,7 @@ func TestRejectSortForMPP(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t (id int, value decimal(6,3), name char(128))")
 	tk.MustExec("analyze table t")
@@ -6709,6 +6711,7 @@ func TestTiFlashFineGrainedShuffle(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("set @@tidb_isolation_read_engines = 'tiflash'")
 	tk.MustExec("set @@tidb_enforce_mpp = on")
 	tk.MustExec("drop table if exists t1;")

planner/core/physical_plan_test.go

@@ -54,6 +54,7 @@ func TestDAGPlanBuilderSimpleCase(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("set tidb_opt_limit_push_down_threshold=0")
 	var input []string
 	var output []struct {
@@ -599,6 +600,7 @@ func TestIndexJoinUnionScan(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("create table t (a int primary key, b int, index idx(a))")
 	tk.MustExec("create table tt (a int primary key) partition by range (a) (partition p0 values less than (100), partition p1 values less than (200))")
 	tk.MustExec(`set @@tidb_partition_prune_mode='` + string(variable.Static) + `'`)
@@ -720,6 +722,7 @@ func TestSemiJoinToInner(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 
 	var input []string
 	var output []struct {
@@ -976,6 +979,7 @@ func TestSemiJoinRewriteHints(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("create table t(a int, b int, c int)")
 
 	sessionVars := tk.Session().GetSessionVars()
@@ -1218,6 +1222,7 @@ func TestForceInlineCTE(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists t;")
 	tk.MustExec("CREATE TABLE `t` (`a` int(11));")
 	tk.MustExec("insert into t values (1), (5), (10), (15), (20), (30), (50);")
@@ -2111,6 +2116,7 @@ func TestSkewDistinctAgg(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("CREATE TABLE `t` (`a` int(11), `b` int(11), `c` int(11), `d` date)")
 	tk.MustExec("insert into t (a,b,c,d) value(1,4,5,'2019-06-01')")

planner/core/plan_cost_ver2.go

@@ -246,13 +246,14 @@ func (p *PhysicalIndexLookUpReader) getPlanCostVer2(taskType property.TaskType,
 	}
 	tableSideCost := divCostVer2(sumCostVer2(tableNetCost, tableChildCost), distConcurrency)
 
-	// double-read
+	// double-read: assume at least 1 row to double-read to avoid 0 double-read cost.
+	doubleReadRows := math.Max(indexRows, 1)
 	doubleReadCPUCost := newCostVer2(option, cpuFactor,
 		indexRows*cpuFactor.Value,
-		"double-read-cpu(%v*%v)", indexRows, cpuFactor)
+		"double-read-cpu(%v*%v)", doubleReadRows, cpuFactor)
 	batchSize := float64(p.ctx.GetSessionVars().IndexLookupSize)
 	taskPerBatch := 32.0 // TODO: remove this magic number
-	doubleReadTasks := indexRows / batchSize * taskPerBatch
+	doubleReadTasks := doubleReadRows / batchSize * taskPerBatch
 	doubleReadRequestCost := doubleReadCostVer2(option, doubleReadTasks, requestFactor)
 	doubleReadCost := sumCostVer2(doubleReadCPUCost, doubleReadRequestCost)
 

planner/core/rule_join_reorder_test.go

@@ -261,6 +261,7 @@ func TestJoinOrderHint4DifferentJoinType(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("drop table if exists t, t1, t2, t3, t4, t5, t6, t7, t8;")
 	tk.MustExec("create table t(a int, b int, key(a));")
 	tk.MustExec("create table t1(a int, b int, key(a));")

planner/core/rule_result_reorder_test.go

@@ -130,6 +130,7 @@ func TestOrderedResultModeOnSubQuery(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
+	tk.MustExec("set tidb_cost_model_version=2")
 	tk.MustExec("set tidb_enable_ordered_result_mode=1")
 	tk.MustExec("drop table if exists t1")
 	tk.MustExec("drop table if exists t2")

planner/core/testdata/analyze_suite_out.json

@@ -424,7 +424,7 @@
     "Name": "TestEmptyTable",
     "Cases": [
       "TableReader(Table(t)->Sel([le(test.t.c1, 50)]))",
-      "LeftHashJoin{TableReader(Table(t)->Sel([not(isnull(test.t.c1))]))->TableReader(Table(t1)->Sel([not(isnull(test.t1.c1))]))->HashAgg}(test.t.c1,test.t1.c1)",
+      "LeftHashJoin{TableReader(Table(t)->Sel([not(isnull(test.t.c1))]))->TableReader(Table(t1)->Sel([not(isnull(test.t1.c1))])->HashAgg)->HashAgg}(test.t.c1,test.t1.c1)",
       "LeftHashJoin{TableReader(Table(t)->Sel([not(isnull(test.t.c1))]))->TableReader(Table(t1)->Sel([not(isnull(test.t1.c1))]))}(test.t.c1,test.t1.c1)",
       "Dual"
     ]

planner/core/testdata/expression_rewriter_suite_out.json

@@ -7,10 +7,9 @@
         "Plan": [
           "HashJoin 2.25 root  inner join, equal:[eq(test.t1.a, test.t2.a) eq(test.t1.b, test.t2.b)]",
           "├─HashAgg(Build) 1.69 root  group by:test.t2.a, test.t2.b, funcs:firstrow(test.t2.a)->test.t2.a, funcs:firstrow(test.t2.b)->test.t2.b",
-          "│ └─TableReader 1.69 root  data:HashAgg",
-          "│   └─HashAgg 1.69 cop[tikv]  group by:test.t2.a, test.t2.b, ",
-          "│     └─Selection 2.25 cop[tikv]  not(isnull(test.t2.a)), not(isnull(test.t2.b))",
-          "│       └─TableFullScan 4.00 cop[tikv] table:t2 keep order:false",
+          "│ └─TableReader 2.25 root  data:Selection",
+          "│   └─Selection 2.25 cop[tikv]  not(isnull(test.t2.a)), not(isnull(test.t2.b))",
+          "│     └─TableFullScan 4.00 cop[tikv] table:t2 keep order:false",
           "└─TableReader(Probe) 2.25 root  data:Selection",
           "  └─Selection 2.25 cop[tikv]  not(isnull(test.t1.a)), not(isnull(test.t1.b))",
           "    └─TableFullScan 4.00 cop[tikv] table:t1 keep order:false"
@@ -37,10 +36,9 @@
         "Plan": [
           "HashJoin 1.69 root  inner join, equal:[eq(test.t2.a, test.t1.a) eq(test.t2.b, Column#7)]",
           "├─HashAgg(Build) 1.69 root  group by:test.t2.a, test.t2.b, funcs:firstrow(test.t2.a)->test.t2.a, funcs:firstrow(test.t2.b)->test.t2.b",
-          "│ └─TableReader 1.69 root  data:HashAgg",
-          "│   └─HashAgg 1.69 cop[tikv]  group by:test.t2.a, test.t2.b, ",
-          "│     └─Selection 2.25 cop[tikv]  not(isnull(test.t2.a)), not(isnull(test.t2.b))",
-          "│       └─TableFullScan 4.00 cop[tikv] table:t2 keep order:false",
+          "│ └─TableReader 2.25 root  data:Selection",
+          "│   └─Selection 2.25 cop[tikv]  not(isnull(test.t2.a)), not(isnull(test.t2.b))",
+          "│     └─TableFullScan 4.00 cop[tikv] table:t2 keep order:false",
           "└─HashAgg(Probe) 2.25 root  group by:test.t1.a, funcs:count(1)->Column#7, funcs:firstrow(test.t1.a)->test.t1.a",
           "  └─TableReader 3.00 root  data:Selection",
           "    └─Selection 3.00 cop[tikv]  not(isnull(test.t1.a))",