* Favoring dependent: :delete_all over :destroy
The `dependent: :destroy` callback is slower than `dependent: :delete`
and `dependent: :delete_all`. We need only favor the `dependent:
:destroy` when there's callbacks that happen.
In the case of :destroy, ActiveRecord instantiates each object and then
runs destroy. Whereas in the case of :delete, ActiveRecord issues a SQL
command to delete the related files.
It is often "safer" to use :destroy, as it guarantees that you'll
instantiate the record and run it's callbacks. But sometimes you have
to go with the speed of SQL.
This relates to #14140. Note there is still more to consider, but given
that we're looking at moving from :destroy on all of an article's page
views to :delete, we might buy enough time in the callback.
* Removing redundancy of article destroy
Prior to this commit, `before_destroy_actions` called the `bust_cache`
method which in turn called `touch_actor_latest_article_updated_at` but
`bust_cache` did not pass the destroying parameter. Then
`before_destroy_actions` immediately called
`touch_actor_latest_article_updated_at` with `destroying: true`.
With this change, we remove one of those duplicate calls.
* Fixing specs regarding relationships
* Fixing specs regarding relationships
