actually needs to be 255 given unicode requirements

lms/djangoapps/notes/migrations/0001_initial.py

@@ -13,7 +13,7 @@ class Migration(SchemaMigration):
             ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
             ('user', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.User'])),
             ('course_id', self.gf('django.db.models.fields.CharField')(max_length=255, db_index=True)),
-            ('uri', self.gf('django.db.models.fields.CharField')(max_length=512, db_index=True)),
+            ('uri', self.gf('django.db.models.fields.CharField')(max_length=255, db_index=True)),
             ('text', self.gf('django.db.models.fields.TextField')(default='')),
             ('quote', self.gf('django.db.models.fields.TextField')(default='')),
             ('range_start', self.gf('django.db.models.fields.CharField')(max_length=2048)),
@@ -82,7 +82,7 @@ class Migration(SchemaMigration):
             'tags': ('django.db.models.fields.TextField', [], {'default': "''"}),
             'text': ('django.db.models.fields.TextField', [], {'default': "''"}),
             'updated': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'db_index': 'True', 'blank': 'True'}),
-            'uri': ('django.db.models.fields.CharField', [], {'max_length': '512', 'db_index': 'True'}),
+            'uri': ('django.db.models.fields.CharField', [], {'max_length': '255', 'db_index': 'True'}),
             'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
         }
     }

lms/djangoapps/notes/models.py

@@ -9,7 +9,7 @@ import json
 class Note(models.Model):
     user = models.ForeignKey(User, db_index=True)
     course_id = models.CharField(max_length=255, db_index=True)
-    uri = models.CharField(max_length=512, db_index=True)
+    uri = models.CharField(max_length=255, db_index=True)
     text = models.TextField(default="")
     quote = models.TextField(default="")
     range_start = models.CharField(max_length=2048)  # xpath string