Credits: migration performance

api/funkwhale_api/music/migrations/0037_track_credit.py

@@ -6,17 +6,15 @@ import django.db.models.deletion
 
 
 def populate_track_credit(apps, schema_editor):
-    from funkwhale_api.music.models import Credit
-
     TrackCredit = apps.get_model("music", "TrackCredit")
     Track = apps.get_model("music", "Track")
 
-    for tk in Track.objects.all():
-        tc = TrackCredit()
-        tc.artist = tk.artist
-        tc.track = tk
-        tc.credit = Credit.MAIN
-        tc.save()
+    tracks = Track.objects.values('artist__id', 'id').iterator()
+    credits = [
+        TrackCredit(artist_id=track['artist__id'], track_id=track['id'], credit="main")
+        for track in tracks
+    ]
+    TrackCredit.objects.bulk_create(credits)
 
 
 def rewind(apps, schema_editor):