Question

I’m slowly transitioning from beginning rails to an intermediate level. In my quest I’m running into problems in the amount of time it’s taking for certain queries to load.

I’m wondering if someone could point out a few things that might improve the performance of my Index Action Query.

Running Rails 3.2.0, ruby 1.9.3p194, and MySQL

Right now I’m listing all institutions (around 7000) and it’s taking 10 sec’s to load …

My Index Action

  def index
    @institution = Institution.includes(:state).all
  end

View

<tbody>
    <% @institution.each do |c| %>
    <tr>
        <td><%= c.company %></td>
        <td><%= c.state.name %></td>
        <td><%= number_to_human(c.assets) %></td>
        <td><%= c.hadademo %></td>
        <td><%= c.datebecameclient %></td>
        <td><%= c.clientorprospect %></td>
        <% if current_user.admin? %>
            <td><%= link_to 'Edit', edit_institution_path(c), :class => 'btn btn-mini btn-warning'  %></td>
        <% end %>
    </tr>
    <% end %>
</tbody>

Institution Model

class Institution < ActiveRecord::Base
  attr_accessible :company, :phone, :clientdate, :street, :city, :state_id, :zip, :source, :source2, :demodate1, :demodate2, :demodate3, :client, :prospect, :notcontacted, :solveid
  belongs_to :state
  has_many :users, :through => :company_reps
  has_many :company_reps


  def points
    points_for_client + points_for_demodate1
  end

  def hadademo
    if demodate3.present?
        demodate3.to_date
    elsif demodate2.present?    
        demodate2.to_date
    elsif demodate1.present?    
        demodate1.to_date
    else
        "No Demo"
    end 
  end

  def datebecameclient
    if clientdate.present?
        clientdate.to_date
    else
        "Not a Client"
    end 
  end

  def clientorprospect
      if client?
            "Client"
        elsif prospect? 
            "Prospect"
        else
            "No Contact"
        end 
  end

  def points_for_demodate1
    if demodate1.present? && demodate1 >= Date.new(2012, 2, 23) or demodate2.present? && demodate2 >= Date.new(2012, 2, 23) or demodate3.present? && demodate3 >= Date.new(2012, 2, 23)
      1
    else
      0
    end
  end

  def clientcount
    if client?
      1
    else
      0
    end
  end

  def points_for_client
    if client?
      10 / users.count
    else
      0
    end
  end


end

Using Jquery Datatables

jQuery ->
    $("#institutions").dataTable
      sDom: "<'row-fluid'<'span6'l><'span6'f>r>t<'row-fluid'<'span6'i><'span6'p>>"
      sPaginationType: "bootstrap"

Log File

Started GET "/institutions" for xxx.xxx.xxx.xxx at 2012-11-13 02:51:47 +0000
Processing by InstitutionsController#index as HTML
  Rendered layouts/_messages.html.erb (1.2ms)
  Rendered institutions/index.html.erb within layouts/application (37190.3ms)
  Rendered layouts/_messages.html.erb (0.1ms)
  Rendered layouts/_navbar.html.erb (17.0ms)
Completed 200 OK in 43334ms (Views: 37983.7ms | ActiveRecord: 340.7ms)
  Rendered institutions/index.html.erb within layouts/application (34329.1ms)
  Rendered layouts/_messages.html.erb (0.1ms)
  Rendered layouts/_navbar.html.erb (23.3ms)
Completed 200 OK in 38824ms (Views: 34374.8ms | ActiveRecord: 82.2ms)

Answer 1

If you look at the log you can see that all of the time is being spent on rendering your view, not the actual query. You will definitely want to implement view or action caching to speed this up.

The official docs will point you in the right direction.