Update the script to set the international flag to do the notifications and notification_history in separate loops.

It takes about 1.5 minutes to update 27,000 notifications and 27,000 notification_history. The update is a row level lock so will only affect updates to the same row.
This is unlikely as the data being updated should be older than 3 days.
The second scripts updates the table to set international as not null, to make the model.

migrations/versions/0082_set_international.py

@@ -1,40 +1,45 @@
 """empty message
 
 Revision ID: 0082_set_international
-Revises: 0080_fix_rate_start_date
+Revises: 0081_noti_status_as_enum
 Create Date: 2017-05-05 15:26:34.621670
 
 """
+from datetime import datetime
+from alembic import op
 
 # revision identifiers, used by Alembic.
-from datetime import datetime
-
 revision = '0082_set_international'
-down_revision = '0080_fix_rate_start_date'
+down_revision = '0081_noti_status_as_enum'
-
-from alembic import op
-import sqlalchemy as sa
 
 
 def upgrade():
     conn = op.get_bind()
     start = datetime.utcnow()
-    all_notifications = "select id from notification_history where international is null limit 10000"
+    notification_history = "select id from notification_history where international is null limit 10000"
 
-    results = conn.execute(all_notifications)
+    results = conn.execute(notification_history)
     res = results.fetchall()
 
-    conn.execute("update notifications set international = False where id in ({})".format(all_notifications))
-    conn.execute("update notification_history set international = False where id in ({})".format(all_notifications))
-
     while len(res) > 0:
-        conn.execute("update notifications set international = False where id in ({})".format(all_notifications))
+        conn.execute("update notification_history set international = False where id in ({})".format(
-        conn.execute("update notification_history set international = False where id in ({})".format(all_notifications))
+            notification_history))
-        results = conn.execute(all_notifications)
+        results = conn.execute(notification_history)
         res = results.fetchall()
+
+    notifications = "select id from notifications where international is null limit 10000"
+    results2 = conn.execute(notifications)
+    res2 = results2.fetchall()
+    while len(res2) > 0:
+        conn.execute("update notifications set international = False where id in ({})".format(notifications))
+
+        results2 = conn.execute(notifications)
+        res2 = results2.fetchall()
+
     end = datetime.utcnow()
     print("Started at: {}   ended at: {}".format(start, end))
 
+
 def downgrade():
     # There is no way to downgrade this update.
     pass