sessionctx: add validation for tidb_enable_plan_replayer_continues_capture

executor/executor_test.go

@@ -204,6 +204,15 @@ func TestPlanReplayerCapture(t *testing.T) {
 func TestPlanReplayerContinuesCapture(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
+
+	tk.MustExec("set @@global.tidb_enable_historical_stats='OFF'")
+	_, err := tk.Exec("set @@global.tidb_enable_plan_replayer_continues_capture='ON'")
+	require.Error(t, err)
+	require.Equal(t, err.Error(), "tidb_enable_historical_stats should be enabled before enabling tidb_enable_plan_replayer_continues_capture")
+
+	tk.MustExec("set @@global.tidb_enable_historical_stats='ON'")
+	tk.MustExec("set @@global.tidb_enable_plan_replayer_continues_capture='ON'")
+
 	prHandle := dom.GetPlanReplayerHandle()
 	tk.MustExec("delete from mysql.plan_replayer_status;")
 	tk.MustExec("use test")

sessionctx/variable/sysvar.go

@@ -1188,12 +1188,29 @@ var defaultSysVars = []*SysVar{
 	/* The system variables below have GLOBAL and SESSION scope  */
 	{Scope: ScopeGlobal | ScopeSession, Name: TiDBEnablePlanReplayerContinuesCapture, Value: BoolToOnOff(false), Type: TypeBool,
 		SetSession: func(s *SessionVars, val string) error {
+			historicalStatsEnabled, err := s.GlobalVarsAccessor.GetGlobalSysVar(TiDBEnableHistoricalStats)
+			if err != nil {
+				return err
+			}
+			if !TiDBOptOn(historicalStatsEnabled) && TiDBOptOn(val) {
+				return errors.Errorf("%v should be enabled before enabling %v", TiDBEnableHistoricalStats, TiDBEnablePlanReplayerContinuesCapture)
+			}
 			s.EnablePlanReplayedContinuesCapture = TiDBOptOn(val)
 			return nil
 		},
 		GetSession: func(vars *SessionVars) (string, error) {
 			return BoolToOnOff(vars.EnablePlanReplayedContinuesCapture), nil
 		},
+		Validation: func(vars *SessionVars, s string, s2 string, flag ScopeFlag) (string, error) {
+			historicalStatsEnabled, err := vars.GlobalVarsAccessor.GetGlobalSysVar(TiDBEnableHistoricalStats)
+			if err != nil {
+				return "", err
+			}
+			if !TiDBOptOn(historicalStatsEnabled) && TiDBOptOn(s) {
+				return "", errors.Errorf("%v should be enabled before enabling %v", TiDBEnableHistoricalStats, TiDBEnablePlanReplayerContinuesCapture)
+			}
+			return s, nil
+		},
 	},
 	{Scope: ScopeGlobal | ScopeSession, Name: TiDBEnablePlanReplayerCapture, Value: BoolToOnOff(true), Type: TypeBool,
 		SetSession: func(s *SessionVars, val string) error {