The script updates 10,000 rows at a time, committing after each one. This should limit the distrubtion to the environment as only the rows being updated will be locked.

It is likely those rows will not have a conflicting update at the same time since the records are older than 3 days.

migrations/versions/0082_set_international.py

@@ -1,6 +1,6 @@
 """empty message
 
-Revision ID: set_notifications_international
+Revision ID: 0082_set_international
 Revises: 0080_fix_rate_start_date
 Create Date: 2017-05-05 15:26:34.621670
 
@@ -9,7 +9,7 @@ Create Date: 2017-05-05 15:26:34.621670
 # revision identifiers, used by Alembic.
 from datetime import datetime
 
-revision = 'set_notifications_international'
+revision = '0082_set_international'
 down_revision = '0080_fix_rate_start_date'
 
 from alembic import op
@@ -19,14 +19,17 @@ import sqlalchemy as sa
 def upgrade():
     conn = op.get_bind()
     start = datetime.utcnow()
-    all_notifications = "select id from notifications where international is null limit 1000"
+    all_notifications = "select id from notification_history where international is null limit 10000"
 
     results = conn.execute(all_notifications)
     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(all_notifications))
-        conn.commit()
         results = conn.execute(all_notifications)
         res = results.fetchall()
     end = datetime.utcnow()