migration to delete user output

u need to run “vacuum full submission” to reduce db file size

submission/migrations/0009_delete_user_output.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+def delete_user_output(apps, schema_editor):
+    Submission = apps.get_model("submission", "Submission")
+    for item in Submission.objects.all():
+        if "data" in item.info and isinstance(item.info["data"], list):
+            for index in range(len(item.info["data"])):
+                item.info["data"][index]["output"] = ""
+        item.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('submission', '0008_submission_ip'),
+    ]
+
+    operations = [
+        migrations.RunPython(delete_user_output, reverse_code=migrations.RunPython.noop)
+    ]