Improve index for calendar query

Add action, target_type, and created_at to the index to improve query
for user's activities

Changelog: performance

db/post_migrate/20211122033501_improve_index_on_events_for_calendar.rb

+# frozen_string_literal: true
+
+class ImproveIndexOnEventsForCalendar < Gitlab::Database::Migration[1.0]
+  INDEX_NAME = 'index_events_author_id_project_id_action_target_type_created_at'
+
+  def up
+    prepare_async_index :events, [:author_id, :project_id, :action, :target_type, :created_at], name: INDEX_NAME
+  end
+
+  def down
+    unprepare_async_index :events, [:author_id, :project_id, :action, :target_type, :created_at], name: INDEX_NAME
+  end
+end

db/schema_migrations/20211122033501

+e010b4c12ae8203d9ea8a4c2035be5e7165aba0030f4d5fd0b0f978f84748707
\ No newline at end of file

lib/gitlab/contributions_calendar.rb

@@ -29,13 +29,13 @@ module Gitlab
       # project_features for the (currently) 3 different contribution types
       date_from = @contributor_time_instance.now.years_ago(1)
       repo_events = event_created_at(date_from, :repository)
-        .where(action: :pushed)
+        .where(action: :pushed, target_type: nil)
       issue_events = event_created_at(date_from, :issues)
         .where(action: [:created, :closed], target_type: "Issue")
       mr_events = event_created_at(date_from, :merge_requests)
         .where(action: [:merged, :created, :closed], target_type: "MergeRequest")
       note_events = event_created_at(date_from, :merge_requests)
-        .where(action: :commented)
+        .where(action: :commented, target_type: "Note")
 
       events = Event
         .select("date(created_at + #{date_interval}) AS date", 'COUNT(*) AS num_events')