Add index to resource_milestone_events

changelogs/unreleased/38096-add-index-on-resource-milestone-events-created-at-pd.yml

+---
+title: Add index for created_at of resource_milestone_events
+merge_request: 28929
+author:
+type: performance

db/migrate/20200406135648_add_index_to_created_at_on_resource_milestone_events.rb

+# frozen_string_literal: true
+
+class AddIndexToCreatedAtOnResourceMilestoneEvents < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  INDEX_NAME = 'index_resource_milestone_events_created_at'
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :resource_milestone_events, :created_at, name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name :resource_milestone_events, INDEX_NAME
+  end
+end

db/structure.sql

@@ -10036,6 +10036,8 @@ CREATE INDEX index_resource_label_events_on_merge_request_id ON public.resource_
 
 CREATE INDEX index_resource_label_events_on_user_id ON public.resource_label_events USING btree (user_id);
 
+CREATE INDEX index_resource_milestone_events_created_at ON public.resource_milestone_events USING btree (created_at);
+
 CREATE INDEX index_resource_milestone_events_on_issue_id ON public.resource_milestone_events USING btree (issue_id);
 
 CREATE INDEX index_resource_milestone_events_on_merge_request_id ON public.resource_milestone_events USING btree (merge_request_id);
@@ -13069,6 +13071,7 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200403184110
 20200403185127
 20200403185422
+20200406135648
 20200407094005
 20200407094923
 \.