Add index on labels title

db/migrate/20160920160832_add_index_to_labels_title.rb

+class AddIndexToLabelsTitle < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def change
+    add_concurrent_index :labels, :title
+  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: 20160915042921) do
+ActiveRecord::Schema.define(version: 20160920160832) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -521,6 +521,7 @@ ActiveRecord::Schema.define(version: 20160915042921) do
   add_index "labels", ["priority"], name: "index_labels_on_priority", using: :btree
   add_index "labels", ["project_id"], name: "index_labels_on_project_id", using: :btree
+  add_index "labels", ["title"], name: "index_labels_on_title", using: :btree
   create_table "lfs_objects", force: :cascade do |t|
     t.string   "oid",                  null: false