tootlab-mastodon/db/migrate/20170322021028_add_lowercase_index_to_accounts.rb

class AddLowercaseIndexToAccounts < ActiveRecord::Migration[5.0]
  def up
    execute 'CREATE INDEX index_accounts_on_username_and_domain_lower ON accounts (lower(username), lower(domain))'
  end

  def down
    remove_index :accounts, name: 'index_accounts_on_username_and_domain_lower'
  end
end