Fast Fail for Missing Indexes (EXPLAIN sanity check)

                  namespace :perf do
  desc 'Explain a hot query to verify it uses indexes'
  task explain_hot_query: :environment do
    sql = Snip.where('score > ?', 100).order(active_at: :desc).limit(20).to_sql
    plan = ApplicationRecord.connection.execute("EXPLAIN #{sql}").values.join("
")
    puts plan
  end
end