planner: refine explain info for batch cop (#20360)

executor/builder.go

@@ -2516,26 +2516,6 @@ func containsLimit(execs []*tipb.Executor) bool {
 	return false
 }
 
-// When allow batch cop is 1, only agg / topN uses batch cop.
-// When allow batch cop is 2, every query uses batch cop.
-func (e *TableReaderExecutor) setBatchCop(v *plannercore.PhysicalTableReader) {
-	if e.storeType != kv.TiFlash || e.keepOrder {
-		return
-	}
-	switch e.ctx.GetSessionVars().AllowBatchCop {
-	case 1:
-		for _, p := range v.TablePlans {
-			switch p.(type) {
-			case *plannercore.PhysicalHashAgg, *plannercore.PhysicalStreamAgg, *plannercore.PhysicalTopN, *plannercore.PhysicalHashJoin:
-				e.batchCop = true
-			}
-		}
-	case 2:
-		e.batchCop = true
-	}
-	return
-}
-
 func buildNoRangeTableReader(b *executorBuilder, v *plannercore.PhysicalTableReader) (*TableReaderExecutor, error) {
 	tablePlans := v.TablePlans
 	if v.StoreType == kv.TiFlash {
@@ -2570,8 +2550,8 @@ func buildNoRangeTableReader(b *executorBuilder, v *plannercore.PhysicalTableRea
 		plans:          v.TablePlans,
 		tablePlan:      v.GetTablePlan(),
 		storeType:      v.StoreType,
+		batchCop:       v.BatchCop,
 	}
-	e.setBatchCop(v)
 	e.buildVirtualColumnInfo()
 	if containsLimit(dagReq.Executors) {
 		e.feedback = statistics.NewQueryFeedback(0, nil, 0, ts.Desc)

planner/core/common_plans.go

@@ -1059,7 +1059,11 @@ func (e *Explain) explainPlanInRowFormat(p Plan, taskType, driverSide, indent st
 			return errors.Errorf("the store type %v is unknown", x.StoreType)
 		}
 		storeType = x.StoreType.Name()
-		err = e.explainPlanInRowFormat(x.tablePlan, "cop["+storeType+"]", "", childIndent, true)
+		taskName := "cop"
+		if x.BatchCop {
+			taskName = "batchCop"
+		}
+		err = e.explainPlanInRowFormat(x.tablePlan, taskName+"["+storeType+"]", "", childIndent, true)
 	case *PhysicalIndexReader:
 		err = e.explainPlanInRowFormat(x.indexPlan, "cop[tikv]", "", childIndent, true)
 	case *PhysicalIndexLookUpReader:

planner/core/initialize.go

@@ -15,6 +15,7 @@ package core
 
 import (
 	"github.com/pingcap/tidb/expression"
+	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/planner/property"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
@@ -418,6 +419,21 @@ func (p PhysicalTableReader) Init(ctx sessionctx.Context, offset int) *PhysicalT
 	if p.tablePlan != nil {
 		p.TablePlans = flattenPushDownPlan(p.tablePlan)
 		p.schema = p.tablePlan.Schema()
+		if p.StoreType == kv.TiFlash && !p.GetTableScan().KeepOrder {
+			// When allow batch cop is 1, only agg / topN uses batch cop.
+			// When allow batch cop is 2, every query uses batch cop.
+			switch ctx.GetSessionVars().AllowBatchCop {
+			case 1:
+				for _, plan := range p.TablePlans {
+					switch plan.(type) {
+					case *PhysicalHashAgg, *PhysicalStreamAgg, *PhysicalTopN:
+						p.BatchCop = true
+					}
+				}
+			case 2:
+				p.BatchCop = true
+			}
+		}
 	}
 	return &p
 }

planner/core/integration_test.go

@@ -582,8 +582,8 @@ func (s *testIntegrationSerialSuite) TestAggPushDownEngine(c *C) {
 	tk.MustQuery("desc select approx_count_distinct(a) from t").Check(testkit.Rows(
 		"StreamAgg_16 1.00 root  funcs:approx_count_distinct(Column#5)->Column#3",
 		"└─TableReader_17 1.00 root  data:StreamAgg_8",
-		"  └─StreamAgg_8 1.00 cop[tiflash]  funcs:approx_count_distinct(test.t.a)->Column#5",
-		"    └─TableFullScan_15 10000.00 cop[tiflash] table:t keep order:false, stats:pseudo"))
+		"  └─StreamAgg_8 1.00 batchCop[tiflash]  funcs:approx_count_distinct(test.t.a)->Column#5",
+		"    └─TableFullScan_15 10000.00 batchCop[tiflash] table:t keep order:false, stats:pseudo"))
 
 	tk.MustExec("set @@session.tidb_isolation_read_engines = 'tikv'")
 

planner/core/physical_plans.go

@@ -75,6 +75,9 @@ type PhysicalTableReader struct {
 	// StoreType indicates table read from which type of store.
 	StoreType kv.StoreType
 
+	// BatchCop = true means the cop task in the physical table reader will be executed in batch mode(use in TiFlash only)
+	BatchCop bool
+
 	IsCommonHandle bool
 
 	// Used by partition table.
@@ -143,6 +146,7 @@ func (p *PhysicalTableReader) Clone() (PhysicalPlan, error) {
 	}
 	cloned.physicalSchemaProducer = *base
 	cloned.StoreType = p.StoreType
+	cloned.BatchCop = p.BatchCop
 	cloned.IsCommonHandle = p.IsCommonHandle
 	if cloned.tablePlan, err = p.tablePlan.Clone(); err != nil {
 		return nil, err