in point get use case, tuning on plan cache will cause performance drop

[lance6716]

Enhancement

diff --git i/pkg/bindinfo/session_handle_test.go w/pkg/bindinfo/session_handle_test.go
index 5d5bc3d7bb..1d61094767 100644
--- i/pkg/bindinfo/session_handle_test.go
+++ w/pkg/bindinfo/session_handle_test.go
@@ -29,6 +29,7 @@ import (
 	"github.com/pingcap/tidb/pkg/server"
 	"github.com/pingcap/tidb/pkg/testkit"
 	"github.com/pingcap/tidb/pkg/util/stmtsummary"
+	"github.com/pingcap/tidb/pkg/util/tracing"
 	"github.com/stretchr/testify/require"
 )
 
@@ -228,6 +229,36 @@ func TestBaselineDBLowerCase(t *testing.T) {
 	))
 }
 
+func TestComparePointGet(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("CREATE TABLE sbtest1 (" +
+		"`id` int NOT NULL AUTO_INCREMENT," +
+		"`k` int NOT NULL DEFAULT '0'," +
+		"`c` char(120) NOT NULL DEFAULT ''," +
+		"`pad` char(60) NOT NULL DEFAULT ''," +
+		"PRIMARY KEY (`id`)," +
+		"KEY `k_1` (`k`))")
+
+	ctx := context.Background()
+	duration := time.Duration(0)
+	ctx = context.WithValue(ctx, tracing.TestDurationCtxKey("test"), &duration)
+	repeat := 10_000
+	for range repeat {
+		tk.MustQueryWithContext(ctx, "select * from sbtest1 where id = 123")
+	}
+	t.Logf("average optimize time for point get: %v", duration/time.Duration(repeat))
+
+	tk.MustExec(`prepare stmt1 from 'select * from sbtest1 where id = ?'`)
+	tk.Exec("set @a = 123")
+	duration = 0
+	for range repeat {
+		tk.MustQueryWithContext(ctx, "execute stmt1 using @a")
+	}
+	t.Logf("average optimize time for point get with prepared statement: %v", duration/time.Duration(repeat))
+}
+
 func TestShowGlobalBindings(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 
diff --git i/pkg/planner/optimize.go w/pkg/planner/optimize.go
index 1c1f06fd6c..9534c19540 100644
--- i/pkg/planner/optimize.go
+++ w/pkg/planner/optimize.go
@@ -133,6 +133,13 @@ func getPlanFromNonPreparedPlanCache(ctx context.Context, sctx sessionctx.Contex
 
 // Optimize does optimization and creates a Plan.
 func Optimize(ctx context.Context, sctx sessionctx.Context, node *resolve.NodeW, is infoschema.InfoSchema) (plan base.Plan, slice types.NameSlice, retErr error) {
+	durP, ok := ctx.Value(tracing.TestDurationCtxKey("test")).(*time.Duration)
+	if ok {
+		now := time.Now()
+		defer func() {
+			*durP += time.Since(now)
+		}()
+	}
 	defer tracing.StartRegion(ctx, "planner.Optimize").End()
 	sessVars := sctx.GetSessionVars()
 	pctx := sctx.GetPlanCtx()
@@ -428,7 +435,7 @@ func allowInReadOnlyMode(sctx planctx.PlanContext, node ast.Node) (bool, error)
 	switch node.(type) {
 	// allow change variables (otherwise can't unset read-only mode)
 	case *ast.SetStmt,
-		// allow analyze table
+	// allow analyze table
 		*ast.AnalyzeTableStmt,
 		*ast.UseStmt,
 		*ast.ShowStmt,
diff --git i/pkg/util/tracing/util.go w/pkg/util/tracing/util.go
index 4e5346a503..d03011c900 100644
--- i/pkg/util/tracing/util.go
+++ w/pkg/util/tracing/util.go
@@ -101,6 +101,8 @@ func StartRegion(ctx context.Context, regionType string) Region {
 	}
 }
 
+type TestDurationCtxKey string
+
 // StartRegionEx returns Region together with the context.
 // Recommended usage is
 //

result

    session_handle_test.go:251: average optimize time for point get: 15.743µs
    session_handle_test.go:259: average optimize time for point get with prepared statement: 52.823µs

[lance6716]

If the optimize time can be reduced to

    session_handle_test.go:253: average optimize time for point get: 16.34µs
    session_handle_test.go:267: average optimize time for point get with prepared statement: 8.001µs

in a sysbench point_select test, QPS can be improved from ~100k to ~108k.