小编mar*_*ers的帖子

pluck当只需要一两个字段时，我一直默认使用，但我最近对性能差异进行了基准测试，并且勇气丢失了：

ActiveRecord::Base.logger.level = 1
n = 5000
Benchmark.bm do |x|
  x.report('Country.all:              ') { n.times { Country.all } }
  x.report('Country.unscoped:         ') { n.times { Country.unscoped } }
  x.report('base priority_order:      ') { n.times { Country.unscoped.with_translations(I18n.locale).order(list_at_top:   :desc).order(:name) } }
  x.report('.includes(:translations): ') { n.times { Country.unscoped.with_translations(I18n.locale).order(list_at_top: :desc).order(:name).includes(:translations) } }
  x.report('.pluck(:name):            ') { n.times { Country.unscoped.with_translations(I18n.locale).order(list_at_top: :desc).order(:name).includes(:translations).pluck(:name) } }
  x.report('.pluck(:name) only:       ') { n.times { Country.unscoped.with_translations(I18n.locale).order(list_at_top: :desc).order(:name).pluck(:name) } }
end

# Results
=begin
                                  user     system      total        real
  Country.all:                0.990000   0.020000   1.010000 (  1.023518)
  Country.unscoped: …