Add index to project_id on the project_registries table

db_geo/migrate/20170302005747_add_index_to_project_id_on_project_registries.rb

+class AddIndexToProjectIdOnProjectRegistries < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def change
+    add_concurrent_index :project_registries, :project_id
+  end
+end

db_geo/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170206203234) do
+ActiveRecord::Schema.define(version: 20170302005747) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -21,4 +21,6 @@ ActiveRecord::Schema.define(version: 20170206203234) do
     t.datetime "last_repository_successful_sync_at"
     t.datetime "created_at", null: false
   end
+
+  add_index "project_registries", ["project_id"], name: "index_project_registries_on_project_id", using: :btree
 end