Attendance

Speed up your Active Record query performance by not loading Active Record objects when calling present?. Inspired by this tweet thread.

While this change is astoundingly small (in code terms) it might not be a good fit for 100% of apps (see the caveats section). This was already discussed then committed and eventually removed from the Rails codebase.

If this gem has legs and lots of people like it then it's a good proxy for a test run of changing the default rails behavior. If everyone hates it, then no harm, remove the gem from your Gemfile.

Add this line to your application's Gemfile:

gem 'attendance'

And then execute:

$ bundle

Or install it yourself as:

$ gem install attendance

That's it. Now when you call present? on an ActiveRecord::Relation or an ActiveRecord::Associations::CollectionProxy object, it will not load it into memory:

Without attendance:

User.where(github: 'schneems').present?
  User Load (1.5ms)  SELECT "users".* FROM "users" WHERE "users"."github" = $1  [["github", "schneems"]]
=> true

With attendance:

User.where(github: 'schneems').present?
  User Exists (1.2ms)  SELECT  1 AS one FROM "users" WHERE "users"."github" = $1 LIMIT $2  [["github", "schneems"], ["LIMIT", 1]]

Note: The SQL query only returns back true/false (SELECT 1) instead of the whole object.

It monkeypatches ActiveRecord::Relation and ActiveRecord::Associations::CollectionProxy to alias blank? to empty?.

We're not entirely sure if this is always a good idea or not, and it may cause extra queries.

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/schneems/attendance. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Attendance project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.