canvas-lms/db/migrate/20180327092617_add_submissi...

30 lines
1.1 KiB
Ruby

# frozen_string_literal: true
#
# Copyright (C) 2018 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
class AddSubmissionDateIndex < ActiveRecord::Migration[5.1]
tag :predeploy
disable_ddl_transaction!
def change
return if index_name_exists?(:submissions, "index_submissions_on_user_and_greatest_dates")
add_index :submissions, "user_id, GREATEST(submitted_at, created_at)", name: "index_submissions_on_user_and_greatest_dates", algorithm: :concurrently
end
end