RailsConsoleBenchmark

A Ruby gem for profiling a block of code from the Rails (or plain Ruby) console. It measures wall time, SQL query count, and memory allocation, then displays the results in a formatted terminal table.

• Wall time — measured via Process.clock_gettime(Process::CLOCK_MONOTONIC), reported in milliseconds (3 decimal places).
• SQL query count — tracked via ActiveSupport::Notifications when ActiveRecord is present. SCHEMA and CACHE queries are excluded.
• Memory allocation — total allocated and retained memory reported via memory_profiler. Memory profiling runs on the first iteration only.
• Multi-iteration support — run the block N times and get min/max/mean/total statistics.
• Rails-optional — works in plain Ruby projects with no ActiveRecord dependency.
• Rails console auto-integration — a Railtie makes RailsConsoleBenchmark available automatically in rails console when bundled in a Rails app.

Add to your application's Gemfile:

bundle add rails_console_benchmark

Or install directly:

gem install rails_console_benchmark

RailsConsoleBenchmark::Tracker.measure do
  MyModel.where(active: true).to_a
end

Example output:

+------------------+------------+
| Metric           | Value      |
+------------------+------------+
| Wall Time (ms)   | 42.371     |
| SQL Queries      | 1          |
| Allocated Memory | 512.00 KB  |
| Retained Memory  | 4.00 KB    |
+------------------+------------+

RailsConsoleBenchmark::Tracker.measure(10) do
  MyModel.where(active: true).to_a
end

Example output:

+------------------+--------+--------+---------+---------+
| Metric           | Min    | Max    | Mean    | Total   |
+------------------+--------+--------+---------+---------+
| Wall Time (ms)   | 38.112 | 56.903 | 44.210  | 442.100 |
| SQL Queries      | 1      | 1      | 1.0     | 10      |
| Allocated Memory | 512.00 KB | 512.00 KB | 512.00 KB | 512.00 KB |
| Retained Memory  | 4.00 KB   | 4.00 KB   | 4.00 KB   | 4.00 KB   |
+------------------+--------+--------+---------+---------+

Memory figures are from the first iteration only, so min/max/mean/total all show the same value.

When ActiveSupport::Notifications is not defined, the SQL Queries row displays N/A.

When the gem is added to a Rails app's Gemfile, a Railtie automatically registers with Rails so RailsConsoleBenchmark is available in rails console without a manual require:

# No require needed — just use it:
RailsConsoleBenchmark::Tracker.measure { MyModel.all.to_a }

• Ruby >= 3.2.0
• memory_profiler ~> 1.0
• terminal-table ~> 3.0
• Rails / ActiveRecord is optional

After checking out the repo, run bin/setup to install dependencies. Then run rake spec to run the test suite. You can also run bin/console for an interactive prompt.

To install the gem locally:

bundle exec rake install

To release a new version, update VERSION in version.rb and run:

bundle exec rake release

This creates a git tag, pushes commits and the tag, and publishes the .gem file to rubygems.org.

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

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

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