Merge branch 'cycle-notification_history-table' of github.com:alphagov/notifications-api into cycle-notification_history-table

app/dao/notifications_dao.py

@@ -372,6 +372,14 @@ def insert_notification_history_delete_notifications(
           ON CONFLICT ON CONSTRAINT notification_history_pkey
           DO NOTHING
     """
+    # Insert data into the pivot table as well. Only needed while we are trying to cycle the history table.
+    insert_pivot_query = """
+           insert into notification_history_pivot
+            SELECT * from NOTIFICATION_ARCHIVE
+             ON CONFLICT ON CONSTRAINT notification_history_pivot_pkey
+             DO NOTHING
+       """
+
     delete_query = """
         DELETE FROM notifications
         where id in (select id from NOTIFICATION_ARCHIVE)
@@ -390,6 +398,8 @@ def insert_notification_history_delete_notifications(
 
     db.session.execute(insert_query)
 
+    db.session.execute(insert_pivot_query)
+
     db.session.execute(delete_query)
 
     db.session.execute("DROP TABLE NOTIFICATION_ARCHIVE")

database_maintenance/cycle_notification_history.sql

@@ -22,7 +22,7 @@ END
 $$;
 
 DROP TRIGGER IF EXISTS update_pivot on notification_history;
--- may need to cancel the autovacuum
+-- Following may be blocked if running vacuum.
 -- select pg_cancel_backend(pid);
 CREATE TRIGGER update_pivot AFTER UPDATE OF notification_status, billable_units, updated_at, sent_by, sent_at ON notification_history
 FOR EACH ROW

migrations/versions/0321_notification_history_pivot.py

@@ -0,0 +1,23 @@
+"""
+
+Revision ID: 0321_notification_history_pivot
+Revises: 0320_optimise_notifications
+Create Date: 2020-03-26 11:16:12.389524
+
+"""
+import os
+
+from alembic import op
+
+revision = '0321_notification_history_pivot'
+down_revision = '0320_optimise_notifications'
+environment = os.environ['NOTIFY_ENVIRONMENT']
+
+
+def upgrade():
+    op.execute('CREATE TABLE notification_history_pivot AS SELECT * FROM notification_history WHERE 1=2')
+    op.execute('ALTER TABLE notification_history_pivot ADD PRIMARY KEY (id)')
+
+
+def downgrade():
+    op.execute('DROP TABLE notifications_history_pivot')