diff --git a/pkg/service/sync_task.go b/pkg/service/sync_task.go
index 19d43a992..94a2bbebb 100644
--- a/pkg/service/sync_task.go
+++ b/pkg/service/sync_task.go
@@ -8,24 +8,33 @@ import (
 
 	"github.com/Masterminds/squirrel"
 	"github.com/jmoiron/sqlx"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
 // SyncTask defines the behaviors for syncing remote records
 type SyncTask struct {
-	Select     squirrel.SelectBuilder
-	Type       interface{}
-	BatchQuery func(ctx context.Context, startTime, endTime time.Time) (interface{}, chan error)
+	// Type is the element type of this sync task
+	// Since it will create a []Type slice from this type, you should not set pointer to this field
+	Type interface{}
+
+	// Select is the select query builder for querying db records
+	Select squirrel.SelectBuilder
+
+	// OnLoad is called when the records are loaded from the database
+	OnLoad func(objs interface{})
 
 	// ID is a function that returns the unique identity of the object
 	ID func(obj interface{}) string
 
 	// Time is a function that returns the time of the object
 	Time func(obj interface{}) time.Time
+
+	// BatchQuery is used for querying remote records.
+	BatchQuery func(ctx context.Context, startTime, endTime time.Time) (interface{}, chan error)
 }
 
 func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Time) error {
-
 	// query from db
 	recordSlice, err := selectAndScanType(ctx, db, sel.Select, sel.Type)
 	if err != nil {
@@ -37,10 +46,17 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 		recordSliceRef = recordSliceRef.Elem()
 	}
 
-	logrus.Debugf("loaded %d records", recordSliceRef.Len())
+	logrus.Debugf("loaded %d %T records", recordSliceRef.Len(), sel.Type)
 
 	ids := buildIdMap(sel, recordSliceRef)
-	sortRecords(sel, recordSliceRef)
+
+	if err := sortRecords(sel, recordSliceRef); err != nil {
+		return err
+	}
+
+	if sel.OnLoad != nil {
+		sel.OnLoad(recordSliceRef.Interface())
+	}
 
 	// default since time point
 	since := lastRecordTime(sel, recordSliceRef, startTime)
@@ -70,7 +86,7 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 				continue
 			}
 
-			logrus.Debugf("inserting %T: %+v", obj, obj)
+			logrus.Infof("inserting %T: %+v", obj, obj)
 			if err := insertType(db, obj); err != nil {
 				return err
 			}
@@ -82,19 +98,24 @@ func lastRecordTime(sel SyncTask, recordSlice reflect.Value, defaultTime time.Ti
 	since := defaultTime
 	length := recordSlice.Len()
 	if length > 0 {
-		since = sel.Time(recordSlice.Index(length - 1))
+		since = sel.Time(recordSlice.Index(length - 1).Interface())
 	}
 
 	return since
 }
 
-func sortRecords(sel SyncTask, recordSlice reflect.Value) {
+func sortRecords(sel SyncTask, recordSlice reflect.Value) error {
+	if sel.Time == nil {
+		return errors.New("time field is not set, can not sort records")
+	}
+
 	// always sort
 	sort.Slice(recordSlice.Interface(), func(i, j int) bool {
 		a := sel.Time(recordSlice.Index(i).Interface())
 		b := sel.Time(recordSlice.Index(j).Interface())
 		return a.Before(b)
 	})
+	return nil
 }
 
 func buildIdMap(sel SyncTask, recordSliceRef reflect.Value) map[string]struct{} {