Revert migration causing timeouts on staging

db/post_migrate/20210526222715_backfill_draft_status_on_merge_requests.rb

 # frozen_string_literal: true
 
 class BackfillDraftStatusOnMergeRequests < ActiveRecord::Migration[6.0]
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  INDEX_NAME = "tmp_index_merge_requests_draft_and_status"
-
-  disable_ddl_transaction!
+  # include Gitlab::Database::MigrationHelpers
 
+  # Marking these as no-op as the original contents caused timeouts on
+  #   staging. Removing the code here per
+  #   #https://docs.gitlab.com/ee/development/deleting_migrations.html#how-to-disable-a-data-migration
+  # =>
   def up
-    add_concurrent_index :merge_requests, :id,
-      where: "draft = false AND state_id = 1 AND ((title)::text ~* '^\\[draft\\]|\\(draft\\)|draft:|draft|\\[WIP\\]|WIP:|WIP'::text)",
-      name: INDEX_NAME
-
-    update_column_in_batches(:merge_requests, :draft, true, batch_size: 100) do |table, query|
-      query
-        .where(table[:state_id].eq(1))
-        .where(table[:draft].eq(false))
-        .where(table[:title].matches_regexp('^\\[draft\\]|\\(draft\\)|draft:|draft|\\[WIP\\]|WIP:|WIP', false))
-    end
-
-    remove_concurrent_index_by_name :merge_requests, INDEX_NAME
+    # no-op
   end
 
   def down
-    remove_concurrent_index_by_name :merge_requests, INDEX_NAME
+    # no-op
   end
 end

spec/migrations/backfill_draft_status_on_merge_requests_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-require Rails.root.join('db', 'post_migrate', '20210526222715_backfill_draft_status_on_merge_requests.rb')
-
-RSpec.describe BackfillDraftStatusOnMergeRequests, :migration do
-  let(:namespaces)     { table(:namespaces) }
-  let(:projects)       { table(:projects) }
-  let(:merge_requests) { table(:merge_requests) }
-
-  let(:group)   { namespaces.create!(name: 'gitlab', path: 'gitlab') }
-  let(:project) { projects.create!(namespace_id: group.id) }
-
-  let(:draft_prefixes) { ["[Draft]", "(Draft)", "Draft:", "Draft", "[WIP]", "WIP:", "WIP"] }
-
-  def create_merge_request(params)
-    common_params = {
-      target_project_id: project.id,
-      target_branch: 'feature1',
-      source_branch: 'master'
-    }
-
-    merge_requests.create!(common_params.merge(params))
-  end
-
-  context "for MRs with #draft? == true titles but draft attribute false" do
-    before do
-      draft_prefixes.each do |prefix|
-        (1..4).each do |n|
-          merge_request = create_merge_request(title: "#{prefix} This is a title", state_id: n)
-          merge_request.update_columns(draft: false)
-        end
-      end
-    end
-
-    it "updates all open draft merge request's draft field to true" do
-      mr_count = merge_requests.all.count
-
-      expect { disable_migrations_output { migrate! } }
-        .to change { MergeRequest.where(draft: false).count }
-        .from(mr_count).to(mr_count - draft_prefixes.length)
-    end
-  end
-end