Question

I have a table that I’d like to keep pruned to the 500 most recent rows. What’s the most efficient way to do this in rails?

Answer 1

One way to do it:

class MyModel
  after_create do
    self.class.prune(500)
  end

  def self.prune(max)
    if count > max
      order('created_at DESC').offset(max).each do |model|
        model.destroy
      end
    end
  end
end

The prune class method could also be added to ActiveRecord::Base if you want to use that on multiple models.