diff --git a/internal/geonames/geonames.go b/internal/geonames/geonames.go
index f184425..ae1c9c8 100644
--- a/internal/geonames/geonames.go
+++ b/internal/geonames/geonames.go
@@ -339,6 +339,8 @@ func GetGeonameCountry(ctx context.Context, country string) ([]Geoname, error) {
 	u := fmt.Sprintf("http://download.geonames.org/export/zip/%s.zip", country)
 	resp, err = pester.Get(u)
 	if err != nil {
+		// Add re-try three times after failing first time
+		// This reduces the risk when network is lagy, we still have chance to re-try.
 		for i := 0; i < 3; i++ {
 			resp, err = pester.Get(u)
 			if err == nil {
diff --git a/internal/schema/migrations.go b/internal/schema/migrations.go
index bab4c17..2ec3bec 100644
--- a/internal/schema/migrations.go
+++ b/internal/schema/migrations.go
@@ -293,7 +293,7 @@ func migrationList(ctx context.Context, db *sqlx.DB, log *log.Logger, isUnittest
 						return errors.WithStack(err)
 					}
 					//fmt.Println("Geoname records: ", len(v))
-
+					// Max argument values of Postgres is about 54460. So the batch size for bulk insert is selected 4500*12 (ncol)
 					batch := 4500
 					n := len(v) / batch