I am trying to optimize my site to do this, I want to know which action causes more requests than others. In any case, to find out the number of database deletions made in one step ?
I found that these gems are very useful for checking problems and optimizing queries
This stone will do exactly what you need: show the number of db requests issued per action:
https://github.com/makandra/query_diet
You can look at the rails log to see how many and how many requests are running for each request. But usually his pain goes through the journal every time to see which request takes time.
I usually use newrelic gem in development to see which actions take longer and will try to optimize queries. See http://newrelic.com/docs/ruby/developer-mode for more information on newrelic in the development model.
Also based on the version of the database and the rails there are other gems ( https://github.com/flyerhzm/bullet ) that tells how the requests are executed in a particular request.