How to skip transaction in ActiveRecord for INSERT ONLY statement?

Question

Look at this example:

2.1.3 :001 > Stat.create!
   (0.1ms)  BEGIN
  SQL (0.3ms)  INSERT INTO `stats` (`created_at`, `updated_at`) VALUES (\'2015-03-16 11:         


        

Answer 1

The problem here is that you want to modify behavior for a class-level method. This is inherently not thread-safe, at the very least for concurrent transactions for other Stat objects. A simple workaround would be to flag the instance as not requiring a transaction:

class Stat < ActiveRecord::Base
  attr_accessor :skip_transaction

  def with_transaction_returning_status
    if skip_transaction
      yield
    else
      super
    end
  end
end

Stat.create! skip_transaction: true

If you are running on a single threaded framework, and therefore aren't concerned with suspending transactions for Stat objects during this time, you can use class level methods and wrap the call like so:

class Stat < ActiveRecord::Base
  def self.transaction(*args)
    if @skip_transaction
      yield
    else
      super
    end
  end

  def self.skip_transaction
    begin
      @skip_transaction = true
      yield
    ensure
      @skip_transaction = nil
    end
  end
end

Stat.skip_transaction { Stat.create! }