Add index on ci_builds.updated_at

changelogs/unreleased/add_index_on_ci_builds_updated_at.yml

+---
+title: Add index on ci_builds.updated_at
+merge_request: 10870
+author: blackst0ne

db/migrate/20170423064036_add_index_on_ci_builds_updated_at.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddIndexOnCiBuildsUpdatedAt < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :ci_builds, :updated_at
+  end
+
+  def down
+    remove_concurrent_index :ci_builds, :updated_at if index_exists?(:ci_builds, :updated_at)
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170419001229) do
+ActiveRecord::Schema.define(version: 20170423064036) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -241,6 +241,7 @@ ActiveRecord::Schema.define(version: 20170419001229) do
   add_index "ci_builds", ["status", "type", "runner_id"], name: "index_ci_builds_on_status_and_type_and_runner_id", using: :btree
   add_index "ci_builds", ["status"], name: "index_ci_builds_on_status", using: :btree
   add_index "ci_builds", ["token"], name: "index_ci_builds_on_token", unique: true, using: :btree
+  add_index "ci_builds", ["updated_at"], name: "index_ci_builds_on_updated_at", using: :btree
 
   create_table "ci_pipelines", force: :cascade do |t|
     t.string "ref"