Performance on selecting all columns instead of specified attributes

Is there a reason the _model_class queries all columns?

https://github.com/cerebris/jsonapi-resources/blob/bf4b4cd7d79da453372880068e167066f0d05f47/lib/jsonapi/active_relation_resource.rb#L286-L288

This is a huge performance impact on models with many columns that may not ever be used by the resource.

It seems for performance reasons it makes sense to only select the attributes defined in the JSONAPI::Resource class.

A workaround for now is to override each resource using .select to retrieve only the fields that are specifically defined.

attributes :name, :address

def self.records(_options = {})
  super.select(self.fields)
end

This should also take into account sparse fieldsets parameters, which would further limit which columns are selected.

Inizia in lib/jsonapi/active_relation_resource.rb, nella query _model_class collegata, e segui come vengono rappresentati gli attributi di Resource e gli sparse fieldsets. Il lavoro è completato quando queste query selezionano solo i campi necessari per la resource e il fieldset richiesto, preservando il comportamento esistente dei records e coprendo i percorsi di query pertinenti.