https://github.com/the-rubies-way/random-rails
The most performed gem to get random record you ever seen! Available for Ruby on Rails with PostgreSQL right now!
https://github.com/the-rubies-way/random-rails
activerecord performance postgresql rails-perfomance random ruby ruby-on-rails sql
Last synced: 8 months ago
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The most performed gem to get random record you ever seen! Available for Ruby on Rails with PostgreSQL right now!
- Host: GitHub
- URL: https://github.com/the-rubies-way/random-rails
- Owner: the-rubies-way
- License: mit
- Created: 2023-07-14T05:57:01.000Z (almost 3 years ago)
- Default Branch: master
- Last Pushed: 2025-10-09T15:34:24.000Z (9 months ago)
- Last Synced: 2025-10-13T21:36:48.936Z (9 months ago)
- Topics: activerecord, performance, postgresql, rails-perfomance, random, ruby, ruby-on-rails, sql
- Language: Ruby
- Homepage:
- Size: 99.6 KB
- Stars: 23
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
[](https://github.com/the-rubies-way/random-rails/actions/workflows/linter.yml)
[](https://github.com/the-rubies-way/random-rails/actions/workflows/test.yml)
[](https://rubygems.org/gems/random-rails)
# RandomRails
🚀 The most performant way to get random records from ActiveRecord. Supports **PostgreSQL**, **MySQL**, and **SQLite** with intelligent strategy selection to replace slow `ORDER BY RANDOM()` queries.
## Why RandomRails?
Traditional `ORDER BY RANDOM()` queries become extremely slow on large tables because they require sorting the entire dataset. RandomRails solves this by using:
- **TABLESAMPLE BERNOULLI** for PostgreSQL (ultra-fast on large tables)
- **Efficient offset-based sampling** for all databases
- **Intelligent strategy selection** based on table size and database type
- **Configurable sampling methods** for different use cases
## Performance Comparison
Real-world benchmark results comparing RandomRails with traditional methods (10 iterations each):
| Sample Size | `ORDER BY RANDOM()` | `User.random()` | `User.sample()` | Performance Gain |
| --------------- | --------------------- | ----------------- | ----------------- | ----------------------- |
| 1,000 users | 3.8359s | **0.2157s** | 347.1409s | **17.79x faster** |
| 10,000 users | 6.1273s | **2.7313s** | 369.7583s | **2.24x faster** |
| 100,000 users | 31.578s | **3.6968s** | 369.4334s | **8.54x faster** |
| 1,000,000 users | 171.497s | **5.3441s** | 373.6102s | **32.09x faster** |
**Key Takeaways:**
- RandomRails consistently outperforms `ORDER BY RANDOM()` by 2-32x
- Performance advantage increases dramatically with table size
- Traditional `User.sample()` method performs poorly at scale
## Installation
Add to your Gemfile:
```ruby
gem "random-rails"
```
Or install directly:
```bash
gem install random-rails
```
## Examples
### Basic Usage
Get a single random record:
```ruby
User.random
# => #
```
Get multiple random records:
```ruby
User.random(count: 5)
# => [#, #, ...]
```
Chain with other ActiveRecord methods:
```ruby
User.where(active: true).random(count: 3)
# => [#, ...]
```
### Advanced Usage
#### Sampling Strategies
RandomRails provides multiple sampling strategies:
```ruby
# Auto-select best strategy (default)
User.random(strategy: :auto)
# Force TABLESAMPLE (PostgreSQL only)
User.random(strategy: :tablesample, precision: 1.0)
# Use efficient offset-based sampling
User.random(strategy: :offset)
# Fallback to ORDER BY RANDOM()
User.random(strategy: :order_by)
```
#### Configuration
Configure RandomRails globally:
```ruby
# config/initializers/random_rails.rb
RandomRails.configure do |config|
config.default_strategy = :auto # Default sampling strategy
config.tablesample_threshold = 10_000 # Use TABLESAMPLE for tables larger than this
config.cache_table_sizes = true # Cache table size estimates
config.precision = 1.0 # Default TABLESAMPLE precision
end
```
#### Database-Specific Features
##### PostgreSQL
- Uses `TABLESAMPLE BERNOULLI` for large tables (> 10k records by default)
- Falls back to offset method for smaller tables
- Fast table size estimation using `pg_class`
##### MySQL
- Uses efficient offset-based sampling
- Table size estimation via `information_schema`
- Fallback to `ORDER BY RAND()` when needed
##### SQLite
- Offset-based sampling for optimal performance
- Graceful handling of table size estimation
- Compatible with in-memory databases
## Benchmarks
RandomRails automatically selects the best strategy for your database and table size. The benchmarks above demonstrate real-world performance improvements across different table sizes, with RandomRails consistently delivering superior performance through intelligent strategy selection:
- **Small tables**: Uses efficient offset-based sampling
- **Large tables (PostgreSQL)**: Leverages `TABLESAMPLE BERNOULLI` for optimal performance
- **All databases**: Falls back to optimized methods when needed
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` 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 the created tag, and push the `.gem` file to [rubygems.org](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/the-rubies-way/random-rails. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [code of conduct](https://github.com/the-rubies-way/random-rails/blob/master/CODE_OF_CONDUCT.md).
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
## Code of Conduct
Everyone interacting in the ActiveRecord::Random project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/the-rubies-way/random-rails/blob/master/CODE_OF_CONDUCT.md).
## Thanks for your support!
[
](https://github.com/railsjazz)