AfterMigrate

Automatically run database maintenance after Rails migrations

after_migrate detects tables touched during rails db:migrate (or related tasks) and runs the appropriate optimizer commands:

• PostgreSQL → ANALYZE (affected tables or all) + optional VACUUM
• SQLite → PRAGMA optimize (or VACUUM + ANALYZE)
• MySQL → ANALYZE TABLE

Stale statistics and fragmentation after schema changes silently hurt query performance.
after_migrate fixes it - automatically and precisely.

Because every migration deserves a cleanup.

• Smart detection of affected tables (CREATE/ALTER/INSERT/UPDATE/DELETE/etc.)
• Zero false positives - ignores views, columns, system tables, and complex joins
• Configurable via environment variables or initializer block
• Supports db:migrate, db:rollback, db:migrate:redo
• No monkey-patching of ActiveRecord core classes
• Works in development, test, CI, and production
• Rails 7.0+ / Ruby 3.2+ only

Add to your Gemfile:

gem 'after_migrate'

Then run:

bundle install

The gem activates automatically. No code required for default behavior.

Out of the box, it runs ANALYZE on only the tables touched during the migration (PostgreSQL default).

Create config/initializers/after_migrate.rb:

AfterMigrate.configure do |config|
  # Enable/disable the gem
  config.enabled = true

  # Log what’s happening
  config.verbose = true

  # Run VACUUM on affected tables (PostgreSQL only)
  config.vacuum = false

  # Choose ANALYZE strategy
  # "only_affected_tables" - default, precise
  # "all_tables"           - full database analyze
  # "none"                 - skip ANALYZE entirely
  config.analyze = "only_affected_tables"

  # Enhance rake tasks (runs maintenance after db:migrate etc.)
  # Set to false in test env if needed
  config.rake_tasks_enhanced = true
end

Bug reports, feature requests, and pull requests are very welcome!

https://github.com/moskvin/after_migrate

This project is available under the MIT License.