README.md

Rails SQL Query Tracker

sql_tracker tracks SQL queries by subscribing to Rails' sql.active_record event notifications.

It then aggregates and generates report to give you insights about all the sql queries happened in your Rails application.

Installation

Add this line to your application's Gemfile:

group :development, :test do
  ... ...
  gem 'sql_tracker'
end

And then execute:

$ bundle

Tracking

To start tracking, simply start your rails application server. When your server is shutting down, sql_tracker will dump all the tracking data into one or more json file(s) under the tmp folder of your application.

sql_tracker can also track sql queries when running rails tests (e.g. your controller or integration tests), it will dump the data after all the tests are finished.

Tracking Using a Block

It is also possible to track queries executed within a block. This method uses a new subscriber to sql.active_record event notifications for each invocation. Results using this method are not saved to a file.

query_data = SqlTracker.track do
  # Run some active record queries
end

query_data.values
# =>
# [{
#  :sql=>"SELECT * FROM users",
#  :count=>1,
#  :duration=>1.0,
#  :source=>["app/models/user.rb:12"]
# }]

Reporting

To generate report, run

sql_tracker tmp/sql_tracker-*.json

The output report looks like this:

==================================
Total Unique SQL Queries: 24
==================================
Count | Avg Time (ms)   | SQL Query                                                                                                 | Source
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
8     | 0.33            | SELECT `users`.* FROM `users` WHERE `users`.`id` = xxx LIMIT 1                                            | app/controllers/users_controller.rb:125:in `create'
      |                 |                                                                                                           | app/controllers/projects_controller.rb:9:in `block in update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
4     | 0.27            | SELECT `projects`.* FROM `projects` WHERE `projects`.`user_id` = xxx AND `projects`.`id` = xxx LIMIT 1    | app/controllers/projects_controller.rb:4:in `update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2     | 0.27            | UPDATE `projects` SET `updated_at` = xxx WHERE `projects`.`id` = xxx                                      | app/controllers/projects_controller.rb:9:in `block in update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2     | 1.76            | SELECT projects.* FROM projects WHERE projects.priority BETWEEN xxx AND xxx ORDER BY created_at DESC      | app/controllers/projects_controller.rb:35:in `index'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
... ...

By default, the report will be sorted by the total count of each query, you can also choose to sort it by average duration:

sql_tracker tmp/sql_tracker-*.json --sort-by=duration

Configurations

All the configurable variables and their defaults are list below:

SqlTracker::Config.enabled = true
SqlTracker::Config.tracked_paths = %w(app lib)
SqlTracker::Config.tracked_sql_command = %w(SELECT INSERT UPDATE DELETE)
SqlTracker::Config.output_path = File.join(Rails.root.to_s, 'tmp')

License

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